1 Heredity and Evolution

CONCEPT MAP
(1)
Heredity
governed by Mendel’s law
Darwin’s theory of Evolution

Evidences of Evolution

I. II. III. IV. V. VI.

Morphological Anatomical Vestigial Paleontological Connecting Embryological
Evidences Evidences Organs Evidences Links Evidences

(2)

Scientist and Year Discovery / Contribution

1 Gregor Johann Mendel, 1886 Series of experiments on pea plant to explain inheritance of characters.
2 Hugo de Vries, 1901 Reasons behind sudden changes.
3 Walter and Sutton, 1902 Paired chromosomes in grasshopper cells.
4 Ostwald Avery, Maclyn, McCarthy All living organisms have genetic material in the form of DNA.
and Colin Macleod (1944) (except viruses)
5 Francois Jacob and Jack Monad, 1961 A model process of protein synthesis with the help of DNA in
bacterial cells.
6 Dr. Har Govind Khorana, 1968 Discovering of triplet codons.
7 Willard Libby, 1960 Developed carbon dating method.
8 Charles Robert Darwin, (1809 - 1882) Proposed the theory of evolution.
9 Jean - Baptiste Lamarck, (1744 - 1829) Activities of the organisms are responsible for their evolution.

(3) Central Dogma of life

DNA

Replication
Reverse
transcription
Transcription

mRNA mRNATranslation Proteins

NUCLEUS CYTOPLASM

(5)
6 Master Key Science and Technology Part-2 (Std. X)

Points to Remember:
● Heredity and hereditary changes
- Heredity is the transfer of biological characters from one generation to another with the help of genes.
- Johann Gregor Mendel is pioneer of modern genetics.
- In 1901, mutational theory was given by Hugo de Vries.
- In 1902, paired chromosomes in the cells of grasshopper were observed by Walter Sutton.'
- In 1944, all living organisms except viruses have DNA as genetic material was proved
by trio of scientists Ostwald Avery, Maclyn McCarthy and Colin MacLeod.
- In 1961, a model was proposed for process of protein synthesis with the help of DNA by Francois Jacob
and Jack Monad.
- Science of heredity is useful for diagnosis, treatment and prevention of heredity disorders, production
of hybrid varieties of animals and plants and in industrial processes in which microbes are used.
● Transcription, Translation and Translocation
- Information about protein synthesis is stored in the DNA and synthesis of appropriate proteins as per
requirement is necessary for body. These proteins are synthesized by DNA through RNA. This is called
as 'Central Dogma'.
- Process of RNA synthesis is called as 'Transcription'.
- The code for each amino acid consists of three nucleotides. It is called as 'Triplet codon'.
- Dr. Har Govind Khorana, made an important contribution in discovery of triplet codons for 20 amino
acids.
- As per the message on mRNA, amino acids are supplied by the tRNA. For this purpose,
tRNA has 'anticodon' having complementary sequence to the codon on mRNA. This is called ‘Translation.’
- The ribosome keeps on moving from one end of mRNA to other end by the distance of one tripletcodon.
This is called 'Translocation' such many chains come together to form complex proteins.
- These proteins control various functions in the body of living organisms and their appearance too.
- Sometimes any nucleotide of the gene changes its position, that causes a minor change which is nothing
but the mutation.
● Evolution
- Formation of new species due to changes in specific characters of several generations of living organ
isms as a response to natural selection is called as evolution.
- 3.5 billion years ago, life had been non-existent on the earth.
First primitive type of cells may have been formed from the mixture of different types of organic and
inorganic compounds.
- There may have been some differences among those cells and according to the principle of natural
selection, some may have shown good growth and some may have perished which could not adjust
with the surrounding.
● Evidences of evolution :
- Morphological evidences : Various similarities like structure of mouth in animals and leaf
Heredity and Evolution 7

shape in plants indicate that there are some similarities in those groups and hence, it proves that their
origin must be same and must have common ancestors.
- Anatomical evidences : There is similarity in structure of bones and bony joints in organs of each of
human, cat, bat and whale. This similarity indicates that those animals may have common ancestors.
- Vestigial organs: Degenerated or underdeveloped useless organs of organisms are called as vestigial
organs. Various vestigial organs like tail bone (coccyx), wisdom teeth and body hair are present in human
beings.
- Paleontological evidences: Remnants and impressions of organisms remain preserved underground.
These are called as fossils.The time passed since the death of a plant or animal can be calculated by
measuring the radioactivity of C-14 and ratio of C-14 to C-12 present in their body. This is called '
carbondating'. It is used in paleontology and anthropology for determining the age of human fossils
and manuscripts.
- Embryological evidences: Comparative study of embryonic developmental stages of various vertebrates
shows that all embryos show similarity during initial stages and those similarities decrease gradually.
● Darwin’s theory of natural selection.
- Charles Darwin published the theory of natural selection which preaches the survival of the fittest.
- Darwin had published a book titled 'Origin of Species'.
● Lamarckism
- Jean-Baptiste Lamarck proposed that morphological changes occurring in living organisms are
responsible for evolution and the reason behind those morphological changes is activities or laziness of
that organism.
- Development of organs due to specific activities or their degeneration due to no use at all was widely
accepted but transfer of those characters from generation to generation was rejected. Because it had been
verified many times that modifications brought in us are not transferred to next generation and thereby,
Lamarck's theory was disproved.
● Speciation
- Formation of new species of plants and animals is the effect of evolution.
- Geographical or reproductive isolation also leads to speciation.
● Human evolution
- Humans are said to have evolved from ancient animals like lemur approximately 7 crore years ago.
- There has been consistent evolution in man since then.
- Apes which started to live on land as forest declined showed gradual developement.
- Their lumbar bones developed, their posture changed and they started using hands.
- These apes then grew up in size and became more intelligent.
- The first human like animal recorded was “Ramapithecus”ape from East Africa.
- Development of apes continued with development of their brains and discovery of fire.
- These developed apes were called as Homo sapiens.
- Neanderthal man was the first Homo sapiens.
- Since then the evolution has been faster.
8 Master Key Science and Technology Part-2 (Std. X)

*Q.1. (A) 2. Complete the statements by choosing

MASTER KEY QUESTION SET - 1 correct options from bracket.
Q.1. (A) 1. Fill in the blanks and rewrite the (Gene, Mutation, Translocation, Transcription,
statements: Gradual development, Appendix)
(1) is pioneer of the modern genetics. (1) The causality behind the sudden changes was
(2) is the transfer of biological understood due to principle of
characters from one generation to another via Hugo de Vries.
genes. (2) The proof for the fact that protein synthesis
(3) Each mRNA is made up of thousands of . occurs through was given by George
(4) Vertebrates have slowly originated from Beadle and Edward Tatum.
. (3) Transfer of information from molecule of DNA to
(5) is the connecting link between mRNA is called as process.
annelida and arthopoda. (4) Evolution means .
(6) Darwin had published a book titled . (5) Vestigial organ present in human
(7) man can be considered as the first body is the proof of evolution.
example of wise man. Ans. (1) Mutation (2) Gene (3) Transcription
(8) is produced as per the sequence of (4) Gradual development (5) Appendix
nucleotides on DNA.
Q.1. (A) 3. Find the odd one out:
(9) There is in RNA instead of thymine of
(1) Transcription, translation, translocation,
DNA.
transpiration.
(10) The code for each amino acid consists of three
Ans. Transpiration - Others are processes of
nucleotides, called as .
complex protein synthesis.
(11) , a scientist of Indian origin
discovered triplet codons for 20 amino acids. (2) Appendix, muscles of ear pinna, wisdom teeth,
long neck of giraffe.
(12) Ribosome keeps moving from one end of mRNA
to other end by the distance of one triplet codon. Ans. Long neck of Giraffe - Others are vestigial organs
This is called as . (3) Cocyx, intestine, wisdom teeth, appendix.
(13) Sometimes, any nucleotide of the gene changes Ans. Intestine - It is a fully functional organ in humans,
its position which cause a minor change which is while others are vestigial organs.
called .
Q.1. (A) 4. Match the columns:
(14) Carbon dating method is developed by .
(15) Ape-like animals reached the South and North- (1) Column ‘A’ Column ‘B’
East Asia and finally evolved into . (1) Walter Sutton (a) All living
(16) The first human-like animals with erect posture organisms have
evolved about years ago. DNA (1944)
(17) First record of human-like animal is in the form
(2) Ostwald Avery, (b) P
 rocess of protein
of ape from East Africa.
Mclyn Mccarthy synthesis (1961)
(18) Human walking with erect posture was evolved and Colin
about years ago.
MacLeod
(19) The evolved about 50 thousand years
(3) Francois Jacob (c) Triplet codons for
ago.
and Jack Monad 20 amino acids
(20) About years ago, wise-man started to
practice agriculture.
Ans. (1) Johann Gregor Mendel (2) Heredity (3) triplet (4) Dr. Har Govind (d) Carbon dating
codons (4) invertebrates (5) Peripatus (6) Origin Khorana
of Species (7) Neanderthal (8) mRNA (9) Uracil (5) Willard Libby (e) Paired
(10) triplet codon (11) Dr. Har Govind Khorana chromosomes
(12) translocation (13) mutation (14) Willard Libby in the cells (1902)
(15) gibbon and orangutan (16) 2 crore
(f) Mutation
(17) Ramapithecus (18) 15 lakh (19) Cro-Magnon man
(20) 10 thousand Ans. (1 – e); (2 – a); (3 – b); (4 – c); (5 – d)
Heredity and Evolution 9

(2) Column ‘A’ Column ‘B’ strands of DNA are used in the process of protein
synthesis. (9) False. The process of RNA synthesis is
(1) Aves and (a) Mesozoic era
Mammals called as transcription. (10) True (11) True (12) True
(13) False. Peripatus is a connecting link between
(2) Reptiles (b) Cenozoic era
annelida and arthropoda. (14) True (15) True
(3) Reptiles, (c) Paleozoic era
amphibia, pisces Q.1. (A) 6. Name the following
(1) First record of human like animal in the form of
Ans. (1 – b); (2 – a); (3 – c)
ape from East Africa.
Q.1. (A) 5. State whether the following statements Ans. Ramapithecus
True or False. Correct the false statements.
(2) He called his concept as principle of ‘use or
(1) Complex proteins control various functions in the disuse of organs’.
body of living organisms and their appearance
Ans. Jean-Baptiste Lamarck
too.
(3) Example indicating that mammals are evolved
(2) Mutation may cause the genetic disorders like
from reptiles and amphibians from fishes.
sickle cell anemia.
Ans. Duck billed platypus, Lungfish
(3) Muscles of ear pinna, which are useful to human,
are useless in monkeys for movement of ear Q.1. (A) 7. Complete the analogy:
pinna. (1) Similarities in characters: Morphological
(4) Evolution is a gradual change occurring in living evidence :: Similarities in structure of bones and
organisms over a long duration. joints : ................................ .
(5) Waltor Sutton is the pioneer of modern genetics. Ans. Anatomical Evidences - Similarities in characters
(6) Ostwald Avery, Mclyn McCarthy and Colin and similarities is structure of bones and joints
Macleod proposed a model for process of protein indicates similar origin with common ancestors.
synthesis with the help of DNA in bacterial cells (2) Similarities in initial stages : ................. .................
(7) Information about protein synthesis is stored in :: Organisms remain preserved underground :
the RNA. Paleontological evidences.
(8) Both the strands of DNA are used in the process Ans. Embryological evidence - In Embryological
of protein synthesis. evidences similarities in initial stages indicate
(9) The process of RNA synthesis is called common origin of animals whereas, Paleotological
translation. evidences have organisms remained preserved
(10) Amino acids are supplied by tRNA . underground.
(11) First living material has been formed in the ocean. (3) ................. ................. : 1,50,000 years ago ::
Cro-Magnon man : 50,000 years ago.
(12) Appendix is useless to humans.
Ans. Neanderthal man - Cro-magnon man evolved
(13) Duckbill platypus is a connecting link between
about 50,000 years ago whereas Neanderthal
annelida and arthropoda.
man evolved about 15,00,000 years ago.
(14) Geographical or reproductive isolation leads to
speciation. (4) 1,00,00,000 years ago : ................. ................. ::
40,000 years ago : Australopithecus.
(15) About 10 thousand years ago, wise man started to
practice agriculture. Ans. Ramapithecus - In the journey of human,
Ramapithecus was evolved 1,00,00000 years ago
Ans. (1) True (2) True (3) False. Muscles of ear pinna,
while Australopithecus was evolved 40,00,000
which are useless to human are useful in monkeys
years ago.
for movement of ear pinna. (4) True (5) False. Johann
Gregor Mendel is the pioneer of modern genetics. Q.1. (B) Choose and write the correct option:
(6) False. French geneticists Francois Jacob and
(1) proved that except viruses, all living
Jack Monad proposed a model for process of protein
organisms have DNA as their genetic material.
synthesis with the help of DNA in bacterial cells.
(a) Ostwald Avery (b) Mclyn McCarthy
(7) False. Information about protein synthesis is
stored in the DNA. (8) False. Only one of the two (c) Colin MacLeod (d) All of these
10 Master Key Science and Technology Part-2 (Std. X)

(2) proposed a model for protein synthesis organisms as a response to natural selection is
with the help of DNA in bacterial cells. called as evolution.
(a) Johann Gregor Mendel (3) Vestigial organs
(b) Walter and Sutton Ans. Degenerated or underdeveloped useless organs
(c) Francois Jacob and Jack Monad of organisms are called as vestigial organs.
(d) Hugo de Vries (4) Carbon dating method
(3) Information about protein synthesis is stored in Ans. The time passed since the death of a plant or
the . animal can be calculated by measuring the
(a) mitochondria (b) DNA radioactivity of C-14 and ratio of C-14 to C-12
(c) RNA (d) ribosomes present in their body. This is carbon dating
(4) brings in the coded message from the method.
DNA. (5) Ancestry of acquired characters
(a) mRNA (b) tRNA (c) rRNA (d) Ribosomes Ans. The living organism can transfer the characters
(5) As per the message on mRNA, amino acids are which it has acquired, to the next generation.
supplied by tRNA. This is called as ………………. This is called Ancestry of acquired characters.
(a) Transcription (b) Translation (6) Central Dogma
(c) Translocation (d) Transportation Ans. Information about protein synthesis is stored
(6) is a gradual change occurring in living in the DNA and synthesis of appropriate
organisms over a long duration. proteins as per requirement is necessary for body.
(a) Evolution (b) Mutation These proteins are synthesized by DNA through
RNA. This is called Central Dogma.
(c) Variation (d) Heredity
(7) Transcription
(7) The theory of natural selection was proposed by
. Ans. The process of RNA synthesis is called as
Transcription.
(a) Mendel (b) Lamarck
(8) Triplet codon
(c) Charles Darwin (d) Hugo de Vries
Ans. The code for each amino acid consists of three
(8) Carbon dating method measures the radioactivity
nucleotides. It is called as Triplet codon.
of C-14 and the ratio of present in the
organism’s body. (9) Translation
(a) C-12 to C-14 (b) C-6 to C-7 Ans. As per the message on mRNA, amino acids are
supplied by the tRNA. For this purpose, tRNA
(c) C-14 to C-12 (d) C-14 to O-16
has ‘anticodon’ having complementary sequence
(9) Mammals have evolved from
to the codon on mRNA. This is called Translation.
(a) aves (b) reptiles
(10) Translocation
(c) amphibians (d) fishes
Ans. The ribosome keeps on moving from one end of
(10) is not a vestigial organ in man. mRNA to other end by the distance of one triplet
(a) Appendix (b) Wisdom tooth codon. This is called Translocation.
(c) Body hair (d) Duodenum (11) Mutation
Ans. (1) (d) All of these (2) (c) Francois Jacob and Jack Ans. Any sudden change that occurs in the
Monad (3) (b) DNA (4) (a) m RNA (5) (b) Translation nucleotide sequence of a gene, causing a minor
(6) (a) Evolution (7) (c) Charles Darwin (8) (c) C-14 or considerable change in the characters of an
to C-12 (9) (b) reptiles (10) (d) Duodenum individual is called mutation.
Q.2.1. Define the following: (12) Fossils
(1) Heredity Ans. Fossils are remnants and impressions of
Ans. Heredity is the transfer of biological characters organisms that remain preserved underground.
from one generation to another via genes. (13) Speciation
(2) Evolution Ans. The formation of new species of plants and
Ans. Formation of new species due to changes in animals as an effect of evolution is termed as
specific characters of several generations of living speciation.
Heredity and Evolution 11

Q.2.2. Write short notes: (vi) Similarly, geographical or reproductive isolation

*(1) Connecting link also leads to speciation.
Ans. *(4) Lamarckism
(i) Some plants and animals show some Ans.
morphological characters by which they can be (i) Jean-Baptiste Lamarck proposed that
related to two different groups; hence, they are morphological changes occurring in living
called connecting links. organisms are responsible for evolution and the
(ii) E.g. In Peripatus, characters like segmented body, reason behind those morphological changes is
thin cuticle and parapodia are present like activities or laziness of that organism.
annelida and worms. Similarly, these animals (ii) The neck of giraffe has become too long due to
show tracheal respiration and open circulatory browsing on leaves of tall plants by extending
system similar to arthropods. This indicates that their neck for several generations.
Peripatus is the connecting link between annelida
(iii) Shoulders of ironsmith have become very strong
and arthropoda.
due to frequent hammering movements.
(iii) Similarly, Duck Billed Platypus lays eggs like
(iv) Wings of birds like emu and ostrich have become
reptiles but shows relationship with mammals
weak due to no use.
too due to presence of mammary glands and hair.
(v) Legs of the birds like swan and duck have
(iv) Lung fish performs respiration with lungs
become useful for swimming due to living in
irrespective of being a fish.
water.
(v) These examples indicate that mammals have
evolved from reptiles and amphibians from (vi) Snakes have lost their legs by modification in
fishes. their body for burrowing habit.

*(2) Embryology (vii) All these examples are types of acquired

characters and are transferred from one
Ans.
generation to another This is called as theory of
(i) Embryology is the science which deals with the inheritance of acquired characters or Lamarckism.
study of development of an organism from an
(viii) Development of organs due to specific
embryo.
activities or their degeneration due to no use
(ii) Comparative study of embryonic developmental
at all was widely accepted but transfer of those
stages of various vertebrates shows that all
characters from generation to generation was
embryos have extreme similarities during initial
rejected.
stages.
(ix) Because it had been verified many times that
(iii) Those similarities decrease gradually.
modifications brought in us are not transferred
(iv) Similarities in initial stages indicate the common
to next generation and thereby Lamarck’s theory
origin for all these animals.
was disproved.
(3) Speciation
Ans. *(5) Dawin’s theory of natural selection
(i) Formation of new species of plants and Ans.
animals through the effect of evolution is called as (i) Charles Darwin, an English biologist published
speciation. the theory of natural selection, which preaches
(ii) Species is the group of organisms that can the survival of the fittest.
produce fertile individuals through natural (ii) According to him, all organisms reproduce
reproduction.
prolifically.
(iii) Each species grow in specific geographical
(iii) These organisms compete with each other and
conditions. Their food, habitat, reproductive
only those organisms who show modification,
ability and period is different.
sustain long.
(iv) Genetic variations are responsible for formation
of new species from earlier one. (iv) Natural selection also plays important role
because nature selects only those organisms
(v) Besides, geographical and reproductive changes
which are fit to live and the rest perish.
are also responsible.
12 Master Key Science and Technology Part-2 (Std. X)

(v) These sustained and selected organisms *(2) What do we call to the process of transfer of
reproduce and give rise to new species with own physical and mental characters from parents to
specific characteristics. the progeny? (Can you recall; Textbook Page No. 1.)
(vi) This theory was widely accepted for long Ans. The process of transfer of physical and mental
duration, however it had some objections to it. characters from parents to the progeny is called
heredity.
(vii) Irrespective of all these objections, Darwin’s work
on evolution has been a milestone. *(3) Which are the components of DNA molecule?
(Can you recall; Textbook Page No. 1)
*(6) Evolution
Ans. DNA has three types of chemical components:
Ans. (1) phosphate (2) a sugar called deoxyribose
(i) Evolution is a gradual change occurring in living (3) four nitrogenous bases-adenine, guanine,
organisms over a long duration. cytosine and thymine.
(ii) This is a very slow-going process through which *(4) What is the function of the appendix of
development of organisms is achieved. our digestive system? (Can you recall; Textbook
(iii) All the stages in changes occurred in various Page No. 3)
components ranging from stars and planets Ans.
in space to the biosphere present on the earth (i) The appendix is a vestigial organ that was once
should be included in the study of evolution. used by our herbivorous ancestors.
(iv) Formation of new species due to changes in (ii) It was found that in herbivorous vertebrates the
specific characters of several generations of appendix is comparatively larger and it helped
living organisms as a response to natural in the digestion of tough herbivorus food such as
selection is called as evolution. the bark of a tree.
(iii) It is also supposed to be a store house of good
(v) Different theories about origin and evolution
bacteria.
of life have been proposed till today of which
theory of gradual development of living *(5) Are our wisdom teeth really useful for chewing
the food? (Can you recall; Textbook Page No. 3)
organisms is accepted.
Ans. No, people do not need wisdom teeth now for
(vi) According to this theory, first living material
chewing the food but earlier they were used for
(Protoplasm) has been formed in the ocean. In due
chewing tough plants which were important part
course of time, unicellular organism was formed.
of the human diet.
(vii) Gradual changes took place in unicellular *(6) Why did the huge animals like dinosaur become
organisms from which larger and more complex extinct? (Can you recall; Textbook Page No. 3)
organisms were formed. Duration of all these
Ans. Inspite of the fact that the cause for dinosaur
changes is about 300 crore years. extinction is still a mystery, following events
(viii) Changes and development in living organisms could have played a role.
has been all round and multi-dimensional (i) Gas seeping and ash evolving from volcanoes
and this led to evolution of different types of suffocated most of the dinosaurs.
organisms. (ii) The entire population of dinosaur may have been
Hence, this overall process is called as evolution wiped out due to diseases.
which is organizational. (iii) The dinosaurs could not survive after a big
(ix) Progressive development of plants and animals meteorite crashed into earth, drastically changing
from the ancestors having different structural the climatic conditions.
and functional organization is called evolution. (iv) Imbalances in food chain leads to starvation of
Q.2.3. Answer in short: the dinosaurs.
*(1) Which component of the cellular nucleus *(7) Why are many species of animals and birds
of living organisms carries hereditary getting extinct? (Can you recall; Textbook Page No. 3)
characters? (Can you recall; Textbook Page No. 1.) Ans.
Ans. Cellular nucleus of living organisms contains (i) Animals and birds extinction may be caused by
the genetic material like DNA, which carries natural occurrences such as climatic heating or
hereditary characters. cooling or changes in sea levels.
Heredity and Evolution 13

(ii) Habitat destruction as farming land expands *(12) Observe the following images and note the
and forests are cut-down. This is the main similarities between given animal images and
cause along with pollution and over fishing or plant images. (Try this; Textbook page 4)
hunting. Ans. Animal Images: We see similarities in the
(8) What objections were raised against Darwin’s structure of mouth, position of eyes, ear pinnae,
theory of natural selection? distribution of hair on their bodies, etc.
Ans. Following are some of the main objections
raised against Darwin’s theory of natural
selection:
(i) Natural selection is not the only factor responsible
for evolution.
(ii) Darwin did not mention any explanation about
useful and useless modifications.
(iii) There is no explanation about slow changes and
abrupt changes.
*(9) Explain the meaning of genetic disorders and
give names of some disorders. (Can you recall;
Textbook Page No. 1) Fig. 1.1: Morphological evidences

Ans. Plant Images : We see similarities in the shape of

leaves, its venation, petiole, colour of their leaves,
(i) Genetic disorders is a problem caused genetically
position and the manner in which the fruits hang
due to mutations in the gene. It is present from from the branches, etc.
birth. Types are rare and affect one in million.
Q.3.1. Read the following statements and justify
(ii) Diabetes, obesity, infertility, cleft palate, heart the same in your own words with the help of
disease, hemophilia , sickle cell anaemia are some suitable examples.
of the genetic disorders. *(1) Human evolution began approximately 7 crore
*(10) Which are the different organs in body of years ago.
organisms? (Can you recall; Textbook Page No. 4.) Ans.

Ans. (i) Last dinosaurs disappeared approximately seven

crore years ago.
(i) In digestive system - (Mouth, Stomach, Liver,
(ii) At that time, monkey like animals were said to be
Pancreas, intestines, etc.)
evolved from some ancestors who were more or
(ii) Skeletal system - (Bones) less similar to the modern lemurs.
(iii) Circulatory system - (Heart, Arteries, Veins, etc.) (iii) Thus, human evolution began approximately
seven crore years ago.
(iv) Respiratory system - (Diaphragm, Lungs, Larynx,
*(2) Geographical and reproductive isolation leads
etc) are some of the organs in an organism.
to speciation.
*(11) Is each of the organs useful to organism? (Can
Ans.
you recall; Textbook Page No. 4.)
(i) Species is the group of organisms that can produce
Ans. fertile individuals through natural reproduction.
(i) Most of the organs are useful to organisms. At (ii) Each species grows in specific geographical
the same time few organs may be present now condition. Their food, habitat, reproductive
but they have lost their function in the process of ability and period is different.
evolution. (iii) Along with genetic variation, geographical
(ii) In human beings, appendix, tail-bone (coccyx), and reproductive changes are responsible for
formation of new species.
wisdom teeth and body hair are not useful now.
14 Master Key Science and Technology Part-2 (Std. X)

(iv) Hence, geographical and reproductive isolation (ii) B - Translation. According to the message on
leads to speciation. mRNA, amino acids are supplied by tRNA and for
*(3) Study of fossils is an important aspect of study this, tRNA has anticodon having complementary
of evolution. sequence of the codon on mRNA. This is called
Ans. translation.
(i) Large number of organisms got buried due to Q.3.3. Draw neat and labelled diagrams of:
disasters like flood, earthquake, volcano, etc. (1) Transcription
(ii) Remnants and impressions of such organisms
remain preserved underground. These are called RNA Polymerase RNA Nucleotides
as fossils.
(iii) With help of carbon-dating technique, it is easy to
determine the age of fossils.
(iv) Once the age of fossil has been determined, it
becomes easy to deduce information about other
erstwhile organisms.
(v) Hence, study of fossils is an important aspect of Transcription
study of evolution.
*(4) There is evidences of fatal science among Fig. 1.2: Transcription
chordates. (2) Translation and Translocation
Ans.
(i) It is believed that chordates have originated from Nucleus
invertebrates.
(ii) It is difficult to find out from which invertebrate
group the chordates were developed.
tRNA mRNA
(iii) Chordate ancestors were soft bodied animals,
hence they were not preserved as fossils. Amino acid
(iv) Thus, there is evidences of fatal science among Ribosome
chordates.
Q.3.2. Complete the following chart:
*(1) mRNA Initial codon
Morphological Paleontological
Fig. 1.3: Translation and Translocation
(3) Mutation
Evidences
of Evolution Main Sequence

Similarities in Vestigial organs

bone structure
Replacement
(2) Complete the flow chart by writing the answers
for ‘A’ and ‘B’ and define them:

DNA A mRNA B Chains of Amino Acids

Ans.
(i) A - Transcription. The process of RNA synthesis
is called transcription. Fig. 1.4: Mutation
Heredity and Evolution 15

Q.3.4. Observe the figure and answer the questions given below:
(1)

Fig. 1.5. Development of Human Brain

(a) What is the picture about? (2)

Ans. It is about the changes in the development of
(4)
Human brain.
Cenozoic
(b) What does the picture of the last man indicate to era
us and what was he called?
Ans. The picture of the last man indicates that the man (3) Mesozoic
era
is wisest of all as his brain is most developed. He
(2)
was called as Homo sapiens.
(c) How did the change happen from first man to
Paleozo-
the last man as shown in the picture?
ic era
Ans. Evolution of the upright man continued in the
direction of developing its brain 20 lakh years (1)
ago upto this age. Many discoveries were made
like fire, practice of agriculture, rearing cattle-
Fig. 1.6: Structure of ground level and fossils
herds, establishing cities, etc. about 10000 years
ago. Cultural development and art of writing (a) Label parts 1 to 4
Ans. 1 - Invertebrates, 2 - Pisces, Amphibia, Reptiles,
developed about 5000 years ago.
3 - Reptiles, 4 - Mammals, Aves
Modern sciences and industrial society developed (b) What is the evidence of evolution shown in the
in recent 200-400 years. picture?
Ans. Paleontological evidence is shown in the picture
by the study of fossil found in the layers of the
ground.
(c) What is Carbon dating?
Ans. (i) Carbon dating is a method used in determining
the age of fossils and manuscripts (ii) The time
16 Master Key Science and Technology Part-2 (Std. X)

passed since the death of a plant or animal can be (i) DNA is made up of nucleotide molecules. A
calculated by measuring the radioactivity of C-14 and phosphate group, a sugar group and a nitrogen
the ratio of C - 14 and C - 12 present in their body. base are present in each nucleotide.
(3) (ii) The nitrogen base is of four types. cytosine (C),
guanine(G), thymine (T), and adenine(A).
(iii) The order in which there nitrogen bases are
present determines the genetic code.
(iv) Human DNA has around 3 billion bases and most
X of the bases are the same in all human beings.
(v) The order of nitrogen, bases forms genes which
instructs cells how to prepare proteins.
(vi) Nucleotides are joined together to form two long
strands that twist to create a structure called a
double helix.
Fig. 1.7
(vii) Adenine pairs with thymine and guanine pairs
(a) Identify the part labelled as ‘X’ with cytosine.
Ans. The part labelled as X is Wisdomtooth. (viii) DNA is coiled tightly to form chromosomes
(b) Name the type of organ shown in the given which are found inside the nucleus.
picture. Various types of RNA
Ans. Vestigial organ.
(c) State any two other examples of such organs in mRNA
humans.
Ans. Other examples of vestigial organs in humans are
coccyx, muscle of ear pinna, body hail, appendix, etc.
Q.4.1. Answer in detail:
*(1) Sketch and explain the structure of DNA and
various types of RNA. (Can you recall; Textbook
Page No. 1)
Ans.

Cytosine
C rRNA
NH2

N
N O
H
Guanine
O
G
NH
N
Base pair NH2
N N
H
Adenine A
H 2N
N
N
N
N
H
Thymine T
O
H3C tRNA
NH
helix of
sugar- N O
phosphates H
Fig. 1.9: Types of RNA
Nucleobases of
(i) Types of RNA are mRNA, rRNA and tRNA.
DNA
(ii) Ribonucleic acid (RNA) is a nucleotide polymer,
DNA (Deoxyribose Nucleic Acid)
which is made of ribose sugar, a phosphate and
Fig. 1.8: Structure of DNA bases such as adenine, guanine, cytosine and uracil.
Heredity and Evolution 17

(iii) The ribose sugar of RNA has a hydroxyl (vi) The message contains the codes for amino acids.
group and it is absent in DNA. RNA has a The code for each amino acid consist of three
structure similar to DNA . nucleotides. It is called as triplet codons.
(iv) rRNA : It is a component of the ribosome (vii) mRNA is made up of thousands of triplet
organelle and helps in protein synthesis codons.
(v) mRNA : It carries information of protein (viii) As per the message on mRNA, amino acids are
synthesis from genes to the ribosomes. supplied by the tRNA.
(ix) For this purpose, tRNA has ‘anticodon’
(vi) tRNA : It carries amino acids up to the ribosomes.
having complementary sequence to the codon on
*(2) How are the hereditary changes responsible for mRNA. This is called as ‘translation’.
evolution? (x) The amino acids brought in by tRNA are
Ans. bonded together by peptide bonds with the help
(i) Formation of new species due to changes in of rRNA.
specific characters of several generations of (xi) During this process, the ribosome keeps on
living organisms as a response to natural moving from one end of the mRNA to the other
selection is called as evolution. end by the distance of one triplet codon. This is
called as ‘translocation’.
(ii) At present, crores of species of plants, range from (xii) Many such chains come together to form
Chlorella to Banyan tree and animals ranging complex proteins.
Amoeba to giant whale are existing on earth. *(4) Explain the theory of evolution and mention
(iii) First primitive cell may have been formed from the proof supporting it.
the mixture of different types of organic and Ans.
inorganic compounds. (i) According to the theory of evolution, first living
(iv) There may have been some differences among material (protoplasm) has been formed in ocean.
these cells and according to the principle of (ii) In due course of time, unicellular organism was
natural selection, some may have shown good formed.
growth and some may have perished which (iii) Gradually, changes occurred in the unicellular
could not adjust with surrounding. organism from which larger and more complex
(v) Sustaining and selected organisms can perform organisms were formed.
reproduction and thereby, give rise to the new (iv) All those changes were slow and gradual.
species with their own specific characters. Duration of all these changes is about 300 crore
*(3) Explain the process of formation of complex years.
proteins. (v) Changes and development in living organisms
has been all round and multi-dimensional
Ans.
and this led to evolution of different types of
(i) Information about protein synthesis is stored in organisms.
the DNA. Synthesis of appropriate proteins as (vi) Hence, this overall process is called as evolution
per requirement is necessary for the body. which is organizational.
(ii) These proteins are synthesized by DNA through (vii) Progressive development of plants and animals
the RNA. This is called as The Central Dogma of from the ancestors having different structural
life. and functional organization is called evolution.
(iii) mRNA is produced as per the sequence of (viii) To support the theory of evolution, various types
nucleotides on DNA. Only one of the two strands of evidences are available.
of DNA are used in this process. (ix) Inspite of many adaptive differences in
(iv) The sequence of nucleotides in mRNA being protoplasm and cell, the manifestation of life
produced is always complementary to the DNA processes like growth, reproduction, metabolism
strand used for synthesis. This process of RNA are essentially same in all organisms.
synthesis is called transcription. (x) Morphological evidences support the theory. It
(v) The mRNA formed in the nucleus comes in is seen that all plants have stem, root, leaf and
cytoplasm. It brings in the coded message from are green in colour and those having green
DNA. colour carry out photosynthesis. Similarly, it is
18 Master Key Science and Technology Part-2 (Std. X)

seen that animals have appendages, eyes, nose, *(6) Define fossil. Explain importance of fossils as
ears, etc. proof of evolution.
(xi) Anatomical evidences like the bone structure of a Ans.
human arm, a bulls leg, a bat’s wing and a whale (i) Remnants and impressions of organisms which
fin have similar structures attributing that they get buried remain preserved underground.
have developed from common ancestors. These are called as fossils. Study of fossils is an
(xii) Vestigial organs like tail bone or coccyx present important aspect of study of evolution.
in humans indicate the link between humans (ii) Carbon consumption of animals and plants stops
who have lost a tail and monkeys who have a tail. after death and since then, only the decaying
(xiii) At embryological level, similarities are observed process of C-14 occurs continuously.
during initial stage which indicates common (iii) In case of dead bodies of plants and animals,
origin.
instead of remaining constant, the ratio between
(xiv) Thus, there are a few evidences which support C-14 and C-12 changes continuously as C-12 is
the fact that evolution is sequential. non-radioactive.
*(5) Explain with suitable examples importance of (iv) The time passed since the death of a plant or
anatomical evidences in evolution. animal can be calculated by measuring the
Ans. radioactivity of C-14 and the ratio of C-14 to C-12
(i) There doesn’t seem any superficial similarity present in their body.
between a human hand, a cat’s foreleg, flipper of
(v) This is carbon dating method. It is used in
a whale and patagium of a bat.
determining the age of human fossils and
(ii) Use of each of these structures is different in manuscripts.
respective animals.
(vi) Once the age of fossil has been determined, it
(iii) However, there is a similarity in structure of
becomes easy to deduce information about other
bones and bony joints in organs of each of these
erstwhile organisms.
animals.
It seem that vertebrates have been slowly
(iv) This similarity indicates that these animals show
originated from invertebrates.
anatomical evolution.

*(7) Write the evolutionary history of modern man.

Ans.
Cro-Magnon
40,00000 Years ago

man 50,000
Australopithecus

erect posture

Years ago
Skilled Human

Neanderthal
Ancient animals like lemurs

Man with

Years ago
15,00,000

Years ago
2,50,00000 Years ago

Ramapithecus

1,50,000
Years ago
20,00,000
1,00,00000
Years ago
7,00,00000 Years ago

Dryopithecus
4,00,00000 Years ago
Egyptopithecus

Fig. 1.10: Journey of human

Heredity and Evolution 19

(i) Approximately seven crore years ago, monkey *(8) Define heredity. Explain the mechanism of
like animals are said to be evolved from some hereditary changes.
ancestors who were more or less similar to the Ans.
modern lemurs. (i) Heredity is the transfer of biological characters
(ii) Tail of these monkey like animals of Africa is said from one generation to another via genes.
to have disappeared about 4 crore years ago. (ii) Living organisms can produce new individuals
like themselves due to genes only and some
(iii) Evolution of some of the 2 crore years old species
of those genes are transmitted to the next
of apes seems to have occurred in different ways.
generation without any changes.
They had to use their hands more for eating food
(iii) Due to this, some of the characters of parents are
and other work.
transmitted to their offsprings.
(iv) First human like animal recorded was
(iv) However, sometimes sudden changes occur in
‘Ramapithecus’ ape from East Africa.
those genes.
(v) This ape grew up in size and became more (v) Sometimes any nucleotide of the gene changes its
intelligent and evolved about 40 lakh years ago. position and that causes a minor change which is
(vi) Skilled humans appeared to be the member of called as mutation.
genus Homo. (vi) Some mutations may be minor but some may be
(vii) About 15 lakh years ago, humans walking with considerable.
erect posture evolved and existed in China and E.g. Mutation may cause the genetic disorder like
Indonesia of Asian continent. sickle cell anaemia.
(viii) Evolution of upright man continued in the (9) Explain with the help of a flow chart the theory
direction of developing its brain for the period of of Evolution.
about 1 lakh years. Ans.
(ix) Brain of 50 thousand year old man had been No life 3.5 million years ago
sufficiently evolved to the extent that it could
be considered as member of the class-wise-man Simple Elements
(Homo sapiens).
(x) Neanderthal man can be considered as the Formation of compounds
example of wise-man.
(xi) The Cro-Magnon man evolved about Formation of Complex compounds in Oceans
50 thousand years ago and afterwards, this
evolution had been faster than the earlier. Formation of organic proteins, nucleic acids
*(7) Define vestigial organs. Write names of some
vestigial organs in human body and write Formation of Protoplasm
the names of those animals in whom same
organs are functional.
Unicellular organisms
Ans.
(i) Degenerated or underdeveloped useless
Multicellular organisms
organs of organisms are called as vestigial
organs.
Larger and complex organisms
(ii) Appendix is a vestigial organ in humans, but is
fully functional in ruminants.
Different plants and animals
(iii) Muscles of ear pinna are vestigial in humans but
are useful in monkey for movement of ear pinna.
20 Master Key Science and Technology Part-2 (Std. X)

Q.4.2. (1) Observe the picture and answer the questions: Q.4.2. (2)
(1)

(2)

(3)
Fig. 1.11. Lamarckism

(a) The picture depicts a theory of use or disuse of

organs. Name it.
Ans. The name of the theory is Lamarckism.
(b) Name the scientist who proposed it.
Ans. Jean - Baptiste Lamarck proposed this theory. Fig. 1.12: Some animals with special characteristics
(c) Give one example and explain the theory with its (a) Observe the picture and identify each organisms.
help. Ans. (i) 1 - Duckbill platypus, 2 - Lungfish, 3 - Peripatus
Ans. Lamarck said that the morphological changes (b) Explain their role in proving the process of
evolution.
occur gradually either due to specific activities
Ans.
or laziness of a particular organism eg. Giraffe’s
(i) Duckbill platypus lays eggs like reptiles and
neck is long due to browning on leaves of tall has hair and mammals glands like mammals
plants by extending its neck. and therefore it is a link between reptiles and
(d) Why was this theory disproved? mammals.
(ii) Lungfish is a fish but breathes with lungs therefore
Ans. Lamarck’s theory of inheritance of acquired
it is a link between amphibians and pisces.
characters was disproved because the (iii) Peripatus is a connecting link between Phylum
modifications brought about in an individual are Annelida and Arthropoda with segmented body,
not transferred to the next generation. parapodia-like appendages and thin cuticle
(Annelida) and breathes through trachea with
open circulatory system (Arthropoda).

vvv
Heredity and Evolution 21

ASSIGNMENT - 1
Time : 1 Hr. Marks : 20

Q.1 (A) Answer the following: (3)

1. Fill in the blanks.
(a) The code for each amino acid consist of three nucleotides called .................. .
(b) Darwin had published a book titled .................. .
2. Example indicating mammals are evolved from reptiles.
Q.1. (B) Choose and write the correct option: (2)
(1) Information about protein synthesis is stored in the ..................
(a) mitochondria (b) DNA (c) RNA (d) ribosomes
(2) is not a vestigial organ in Human.
(a) Appendix (b) Wisdom tooth (c) Body hair (d) Duodenum
Q. 2. Answer the following (Any 2) (4)
(1) Give reason : Geographical and reproductive isolation of organisms gradually leads to speciation.
(2) What is carbon dating method?
(3) Complete the flow chart.

Evidences of Evolution

Q. 3. Answer the following (Any 2) (6)
(1) Write short note on connecting link.
(2) With the help of diagram explain different types of RNA.
(3) Study of fossil is an important aspect of study of evolution. Explain.
Q.4. Answer in detail (Any 1) (5)
1

4 5

(a) Identify 6 state its function. Label parts 1, 2, 3, 4 & 5.

(b) Which two processes are shown in this diagram? Define them.
(c) Observe the diagram carefully and explain in brief.
(2) Explain three evidences of evolution giving examples.
vvv
 2 Life Processes In Living Organisms Part - 1

CONCEPT MAP
(1)
Cellular Respiration

Aerobic Respiration Anaerobic Respiration

(Oxygen is involved) (Oxygen is not involved)

Glycolysis

Glycolysis Tricarboxylic acid cycle Electron transfer chain

(cytoplasm) (mitochondria) reaction (mitochondria) Fermentation
forms Acetyl - CoA
gets oxidized

2 molecules of CO2, H2O, 3 molecules of ATP are obtained from

Pyruvic acid, NADH2, FADH2 NADH2 molecule and 2 molecules of
ATP, NADH2 ATP are obtained from each FADH2
are formed
and H2O molecule + CO2 and H2O + energy

(2) Cell division

Mitosis Meiosis

Karyokinesis (nuclear Cytokinesis Meiosis - I Meiosis - II

division) (cytoplasmic division)

Prophase Metaphase Anaphase Telophase

Prophase - I Metaphase - I Anaphase - I Telophase - I

Prophase - II Metaphase - II Anaphase - II Telophase - II

Leptotene
Zygotene
Pachytene
Diplotene
Diakinesis

(22)
Life Processes In Living Organisms Part - 1 23

Points to Remember:
zz Living organisms and life processes:
zz Various organ-systems are continuously performing their functions in human body. Along with the various
systems like digestive, respiratory, circulatory, excretory and control systems, different external and internal
organs are performing their functions independently but through a complete co-ordination.
zz Living organisms and energy production :
In living organisms, respiration occurs at two levels as body and cellular level.
zz Oxygen and Carbon dioxide are exchanged between body and surrounding in case of respiration occuring
at body level.
zz Cellular respiration occurs among the living organisms by two methods:
- aerobic respiration (oxygen is involved).
- anaerobic respiration (oxygen is not involved).
zz In aerobic respiration, glucose is oxidized in three steps: -
- Glycolysis
- Tricarboxylic acid cycle
- Electron transfer chain reaction
zz ATP - Adenosine triphosphate is an energy rich molecule and energy is stored in the bonds by which
phosphate groups are attached to each other.
zz Fatty acids and amino acids are converted into acetyl-CoA and energy is obtained through complete oxidation
of acetyl-CoA by the process of kreb’s cycle in mitochondria.
zz Energy Production in micro-organisms is through anaerobic respiration. Bacteria perform anaerobic
respiration for energy production.
zz Some higher plants, animals and aerobic micro-organisms also perform anaerobic respiration instead of
aerobic respiration if there is depletion in oxygen level in the surroundings.
zz Glycolysis and fermentation are two steps of anaerobic respiration.
- Seeds perform anaerobic respiration if the soil in submerged under water during germination.
- Our muscle cells perform anaerobic respiration while performing exercise.
zz Energy from different food components:
- We get 4 kcal energy per gram of carbohydrates.
- We get 4 kcal of energy per gram of proteins.
- We get 9 kcal energy per gram of lipids.
- Vitamins are a group of heterogeneous compounds of which, each is essential for proper operation of
various processes in the body.
- Water is an essential nutrient.
- Functioning of cells and thereby whole body disturbs even if there is a little loss of water from the body.
- Fibres help in the digestion of other substances and egestion of undigested substances. Fibre is also an
essential nutrient.
zz Cell Division: It is an essential life process.
zz Cell division is one of the very important properties of cells and living organisms. Due to this property only
a new organism is formed from an existing one.
zz There are two types of cell division - Mitosis and Meiosis.
zz Mitosis occurs in somatic cells and stem cells of the body, whereas meiosis occurs in germ cells.

zz Mitosis is essential for growth of the body. Besides, it is necessary for restoration of the emaciated body,
wound healing, formation of blood cells, etc.
24 Master Key Science and Technology Part-2 (Std. X)

Q.1. (A) 2. Fill in the blanks and rewrite the statement:

MASTER KEY QUESTION SET - 2
(1) Energy from food is obtained in the form of
*Q.1. (A) 1. Fill in the blanks and explain the statement: .
(1) After complete oxidation of a glucose molecule, (2) Process of glycolysis occurs in .
number of ATP molecules are (3) Pyruvic acid formed in glycolysis is converted
into two molecules of .
formed.
(4) Tricarboxylic acid cycle (Kreb’s cycle) takes place
(2) At the end of glycolysis, molecule
in .
are obtained.
(5) Chemically ATP is triphosphate molecule formed
(3) Genetic recombination occurs in from .
phase of prophase of meiosis I. (6) ATP is called as of the cell.
(4) All chromosomes are arranged parallel to (7) Process of glycolysis was discovered by .
equatorial plane of cell in phase of (8) The cylical reactions of tricarboxylic acid were
mitosis. discovered by .
(5) For formation of plasma membrane, (9) and are two steps of anaerobic
molecules are necessary. respiration.
(10) During exercise, accumulates in the
(6) Our muscles cells perform type of
muscles due to which we feel tried.
respiration during exercise.
(11) We get energy per gram of
Ans. carbohydrates and per gram of protein.
(1) 38. The 34 ATP molecules generated through the (12) Electron transfer chain reaction is operated in
electron transfer chain, along with 2 molecules only.
each of ATP, are generated through glycolysis and (13) Excess of carbohydrates are stored in liver and
Kreb’s cycle form a net total of 38 ATP molecules. muscles in the form of .

(2) Pyruvic acid. A molecule of glucose is oxidized (14) Proteins are the macromolecules formed by
bonding together many .
step by step in the process of glycolysis where
(15) are obtained after digestion of proteins.
two molecules of each, i.e. pyruvic acid, ATP,
NADH2 and water are formed. (16) Excess protein are converted into glucose by the
process of .
(3) Pachytene. During Meiosis-I, in pachytene stage,
(17) An enzyme present in the plant
recombination / crossing over, i.e. exchange of chloroplasts is most abundant protein found in
genetic material takes place between non-sister nature.
chromatids of homologous chromosomes. (18) The substances formed by specific chemical bond
(4) Metaphase. Nuclear membrane completely between fatty acids and alcohol are called as
disappears in metaphase. Chromosomes .
completely condense and become clearly visible (19) are required to form the covering
along with sister chromatids. The chromosomes around the axons of nerve cells.
get parallely arranged to the equatorial plane of (20) We get of energy per gram of lipids.
the cell. (21) Excess of lipids are stored in in the
body.
(5) Phospholipids. They form the basic structure of
(22) are mainly utilized for production of
cell membrane which are essential for the semi-
energy required for daily need.
permeability of the plasma membrane.
(23) There is about water in our body.
(6) Anaerobic. During exercise, the oxygen supply (24) occurs in formatic cells and stem cells
may not be enough for the need of muscles. of the body.
Hence, anaerobic respiration occurs in the muscle (25) The two main steps of cell division are
cells and lactic acid accumulates, which is a result and .
of fermentation during which glucose is broken (26) Condensation of thin thread like chromosomes
down by anaerobic respiration. starts in .
Life Processes In Living Organisms Part - 1 25

(27) Nuclear membrane completely disappears in (4) NADH2 : Nicotinamide Adenine Dinucleotide : :
. FADH2 :
(28) Special type of flexible protein fibres called Ans. Flavin Adenine Dinucleotide - NADH2 stands for
are formed between centromere of each Nicotine Amide Dinucleotide and FADH2 stands
chromosome and both centrioles. for Flavin Adenine Dinucleotide
(29) Chromosomes complete their condensation and (5) Glycolysis : Cytoplasm : : Tricarboxylic acid cycle
become clearly visible along with their sister : .
chromatids during . Ans. Mitochondria - Glycolysis takes place in the
(30) The chromosomes reach opposite poles of the cell cytoplasm, whereas TCA cycle (Tri-carboxylic
and start to decondense during . acid) takes place in the mitochondria.
(31) is essential for growth, restoration of (6) Fats : Fatty acids : : Proteins : .
emaciated body wound healing, formation of Ans. Amino acids - Fats are broken down into fatty
blood cells, etc. acids whereas, proteins are broken down into
(32) In , recombination / crossing over amino acids.
occurs between homologous chromosomes. (7) Vitamins A, D, E, K ; Fat-soluble : : Vitamins B
(33) Process of gamete formation and spore formation and C : .
occurs by . Ans. Water soluble - Vitamins A, D, E and K are
fat-soluble vitamins, whereas vitamin B and C
(34) Proteins of animal origin are called
are water soluble vitamins.
proteins.
(8) Mitosis : Somatic cells : : Meiosis : .
Ans. (1) ATP (2) cytoplasm (3) Acetyl - coenzyme A
(4) mitochondria (5) Adenosine ribonucleoside Ans. Germ cells - Mitosis occurs in somatic cells of the body,
(6) energy currency (7) Gustav Embden, Otto whereas meiosis occurs in the germ cells of the body.
Meyrhof and Jacob Parnas. (8) Sir Hans Kreb (9) Nuclear division : karyokinesis : : Cytoplasmic
(9) Glycolysis, fermentation (10) lactic acid (11) division : .
4 Kcal (12) mitochondria (13) glycogen (14) Ans. Cytokinesis - Karyokinesis is the process of division
amino acids (15) Amino acid (16) gluconeogenesis of nucleus of a cell during phase of division, while
(17) RuBisCO (18) lipids (19) Fatty acids (20) 9 Kcal cytokinesis is the process of division of cytoplasm of
(21) Adipose connective tissue (22) Carbohydrates the cell.
(23) 65 - 70% (24) Mitosis (25) Karyokinesis, (10) Blood : Haemoglobin : : Bones : .
Cytokinesis (26) Prophase (27) Metaphase (28) spindle Ans. Ossein - Haemoglobin is a protein present in blood
fibres (29) Metaphase (30) telophase (31) Mitosis whereas, ossein is a protein present is bones.
(32) Meiosis - I (33) Meiosis (34) first class
(11) Vitamin B3 : Nicotinamide : : Vitamin B2 : .
Note: RuBisCO - It stands for Ribulose - 1, 5, -
Ans. Riboflavin - Vitamin B3 is also called as Nitotinamide,
Bisphosphate carboxylase Oxygenase. It is written
whereas Vitamin B2 is also known as Riboflavin.
as ‘RuBisCo.
(12) Fermentation of yeast : Alcohol : : Fermentation of
Q.1. (A) 3. Complete the correlation: erythrocytes: .
(1) Carbohydrates : 4 Kcal of energy : : Lipids : Ans. Lactic acid - Alcohol is produced by fermentation in
. yeast, whereas lactic acid is produced by fermentation
Ans. 9 Kcal of energy - We get 4 Kcal of energy per in erythrocytes.
gram of carbohydrates, whereas we get 9 Kcal of Q.1. (A) 4. Match the following:
energy per gram of lipids.
(2) Glycolysis : EMP Pathway : : Tricarboxylic acid (1) Column A Column B
cycle : . (1) Aerobic respiration (a) Nuclear division
Ans. Kreb’s cycle - Another name for Glycolysis (2) Anaerobic (b) Oxygen is
is EMP pathway, similarly another name for respiration involved
Tricarboxylic acid cycle is Kreb’s cycle. (3) Karyokinesis (c) Cytoplasmic
(3) NADH2 : 3 molecules of ATP : : FADH2 : division
Ans. 2 molecules of ATP - 3 molecules of ATP are obtained (4) Cytokinesis (d) Oxygen is not
from each NADH2 molecule while 2 molecules of involved
ATP are obtained from each FADH2 molecule. Ans. (1 – b), (2 – d), (3 – a), (4 – c)
26 Master Key Science and Technology Part-2 (Std. X)

(2) Column A Column B (17) Vitamins B and C are water - soluble vitamins.
(1) Formation of (a) Prophase (18) We can digest fibres.
spindle fibres (19) 2 molecules of ATP are obtained from each
(2) Sister chromatids (b) Telophase FADH2 molecule.
are pulled apart (20) Before cell division, the cell doubles up its
(3) Nuclear membrane (c) Metaphase chromosome number.
and nucleolus
(21) All chromosomes are arranged parallel to the
reappear
(4) Centrioles (d) Anaphase equatorial plane of the cell in anaphase.
duplicate and (22) Condensation of thin thread - like chromosomes
move to opposite starts in telophase.
poles (23) Sister chromatids are pulled apart in metaphase.
Ans. (1 – c), (2 – d), (3 – b), (4 – a) (24) Plant cell divides by formation of a notch at the
equatorial plane of the cell.
(3) Column A Column B
(25) Seeds perform anaerobic respiration if the soil is
(1) Actin and Myosin (a) Pancreas submerged under water.
(2) Ossein (b) Skin
Ans. (1) False. Only food stuff is not sufficient for energy
(3) Insulin (c) Bones
production, but oxygen is also necessary. (2) True
(4) Melanin (d) Muscles
(3) True (4) False. Meiosis occurs in germ cells.
Ans. (1 – d), (2 – c), (3 – a), (4 – b) (5) False. Nucleolus also appears in each daughter
Q.1. (A) 5. State whether the following statements nucleus. (6) True (7) False. We get 4 Kcal of energy
are True or False. Correct the false statements: per gram of carbohydrates. (8) True (9) False.
Glycolysis is also called as EMP pathway. (10) False.
(1) Only food stuff is sufficient for energy production. During anaerobic respiration of muscles, lactic
(2) Process of glycolysis occurs in cyloplasm. acid accumulates in the muscles due to which we
(3) Amino acids are obtained after digestion of feel tired. (11) True (12) False. Proteins of animal
proteins. origin are called as first class proteins. (13) True
(14) False. We get 9 Kcal of energy per gram of lipids.
(4) Meiosis occurs in somatic cells and stem cells of
(15) False. Each cell contains 70% water by weight.
the body.
(16) True (17) True (18) False. We cannot digest fibres.
(5) Nucleolus does not appear in each daughter (19) True (20) True (21) False. All chromosomes
nucleus. are arranged parallel to the equatorial plane of the
(6) Meiosis II is just like mitosis. cell in metaphase. (22) False. Condensation of thin
(7) We get 9 Kcal of energy per gram of carbohydrates. thread - like chromosomes starts in prophase.
(23) False. Sister chromatids are pulled apart in
(8) Tricarboxylic acid cycle (Kreb’s cycle) occurs in
anaphase. (24) False.Plant cell divides by formation
mitochondria.
of a cell plate along the midline of the cell. (25) True
(9) Glycolysis is also called Kreb’s cycle.
Q.1. (A) 6. Name the following:
(10) During anaerobic respiration of muscles, citric (1) Organ systems performing their functions in
acid accumulates in the muscles due to which we human body.
feel tired.
Ans. Digestive, respiratory, circulatory, excretory
(11) Glucose is incompletely oxidised in anaerobic systems
respiration. (2) Main sources of energy needed to perform organ
(12) Proteins of plant origin are called as first class systems.
proteins. Ans. Carbohydrates, Fats and Lipids
(13) Excess of amino acids obtained from proteins are (3) Two methods of cellular respiration.
not stored in the body.
Ans. Aerobic respiration and Anaerobic respiration
(14) We get 4 Kcal of energy per gram of lipids. (4) Enzymes formed in the cells and used in celluar
(15) Each cell contains 50% water by weight. respiration.
(16) Blood plasma contains 90% of water. Ans. NADH2 and FADH2
Life Processes In Living Organisms Part - 1 27

(5) Three scientists who discovered process of (6) FADH2 : Falvin adenine dinucleotide
glycolysis. (7) EMP pathway : Embden - Meyerhof - Parnas
Ans. Gustav Embden, Otto Meyerhof and Jacob Parnas pathway
(6) Scientist who discovered cyclical reaction of TCA (8) ATP : Adenosine triphosphate
cycle. (9) RuBisCO : Ribulose - 1, 5 - Bisphosphate
Ans. Sir Hans Kreb Carboxylase Oxygenase
(7) Two steps of anaerobic respiration Q.1. (B) Choose and write the correct option:
Ans. Glycolysis and Fermentation (1) Which of the following protein is present in skin?
(8) Process through which excess of proteins are (a) Haemoglobin (b) Insulin
converted into other useful substances like (c) Keratin (d) Ossein
glucose
(2) Which one of the folowing vitamin is not fat
Ans. Gluconeogenesis soluble?
(9) Six types of vitamins (a) D (b) K (c) A (d) C
Ans. A, B, C, D, E and K (3) Water content of Blood Plasma is ....................... .
(10) Fat soluble vitamins (a) 70% (b) 90% (c) 65% (d) 50%
Ans. A, D, E and K (4) In which stage the nuclear membrane completely
(11) Water soluble vitamins disappears during nuclear division?
Ans. B, C (a) Prophase (b) Metaphase
(12) Two types of cell division (c) Anaphase (d) Telophase
Ans. Mitosis and Meiosis (5) Number of chromosomes in diploid cell .............. .
n
(13) Two steps of Mitosis (a) n (b) 3n (c) (d) 2n
2
Ans. Karyokinesis and Cytokinesis (6) In which type of cells meiosis occurs?
(14) Four steps of Karyokinesis (a) Germ cells (b) Stem cells
(c) Somatic cells (d) Epithelial cell
Ans. Prophase, Metaphase, Anaphase and Telophase.
(7) Which vitamin is called riboflavin?
(15) Two steps of Meiosis
(a) A (b) B5 (c) B2 (d) C
Ans. Meiosis I and Meiosis II
(8) In which part of cell, electron transfer chain
(16) Most abundant protein found in nature.
reaction occurs?
Ans. RuBisCO
(a) Cytoplasm (b) Mitochondria
(17) Energy currency of the cell
(c) Nucleus (d) Golgi body
Ans. ATP
(9) Which of the following vitamins are required for
(18) Phase in which chromosomes reach opposite the production of FADH2 and NADH2?
poles of the cell
(a) Vitamin E (b) Nicotinamide
Ans. Anaphase (c) Vitamin C (d) Vitamin D
(19) Protein found in skin (10) The protein ossein is produced in ....................... .
Ans. Melanin, keratin (a) blood (b) muscles
(20) Protein found in muscles (c) bone (d) pancreas
Ans. Actin and Myosin (11) The Spindle fibres start appearing from
....................... stage of Karyokinesis.
Q.1. (A) 7. Write the full form of:
(a) Prophase (b) Metaphase
(1) FAD : Flavin adenine dinucleotide
(c) Anaphase (d) Telophase
(2) FMN : Flavin mononucleotide
(12) In case of plants, which of the following is not
(3) NADP : Nictoninamide adenine dinucleotide
present during cytokinesis?
phosphate
(a) Spindle fibres (b) Cell Plate
(4) TCA cycle : Tricarboxylic acid cycle
(c) Chromosomes (d) Nucleolus
(5) NADH2 : Nicotinamide Adenine dinucleotide
28 Master Key Science and Technology Part-2 (Std. X)

Ans. (1) (c) Keratin (2) (d) C (3) (b) 90% (4) (b) Metaphase (12) Coenzyme
(5) (d) 2n (6) (a) Germ cells (7) (c) B2 (8) (b) Mitochondria Ans. A coenzyme is a non protein compound that is
(9) (b) Nicotinamide (10) (c) bone (11) (b) Metaphase necessary for the functioning of an enzyme.
(12) (a) Spindle fibres
(13) Gluconeogenesis
Q.2.1. Define the following:
Ans. Formation of glucose through non carbohydrate
*(1) Nutrition sources such as a protein is called Gluconeogenesis.
Ans. The process of intake of food and its utilization by Q.2.2. Answer the following in one or two sentences:
an organism is called as nutrition.
*(1) How many atoms of C, H and O are respectively
*(2) Nutrients present in a molecule of glucose?
Ans. Nutrients are components of food which provide (Can you recall - Textbook Page No. 13)
energy and help in growth and maintenance of the
Ans. There are 6 atoms of C, 12 atoms of H and 6 atoms
body.
of O present in a molecule of glucose (C6H12O6).
*(3) Proteins
*(2) Which types of chemical bonds are present
Ans. Proteins are the macromolecules formed by between all atoms in a molecule of glucose?
bonding together many amino acids. (Can you tell - Textbook Page no. 13)
*(4) Cellular respiration Ans. Covalent bonds are present between all atoms in a
Ans. Cellular respiration is a process where foodstuffs molecule of glucose.
are oxidised either with or without the help of (3) How much energy do we get from carbohydrates,
oxygen to produce energy.
lipids and protein?
*(5) Aerobic respiration
Ans. We get 4 kcal of energy per gram of carbohydrates
Ans. Aerobic respiration is the process of producing and proteins, and 9 kcal of energy per gram of lipids.
energy from foodstuffs with the help of oxygen.
* (4) What do you mean by diploid cell?
*(6) Glycolysis (Brain power - Textbook Page No. 20)
Ans. Glycolysis is the process in which a molecule of Ans. A diploid cell is a cell that contains two sets of
glucose is oxidized in a step by step process and chromosomes. (2n)
two molecules of each, i.e. pyruvic acid, ATP,
* (5) What do you mean by haploid cell?
NADH2 and water are formed.
(Brain power - Textbook Page No. 20)
(7) Fermentation
Ans. Haploid cell is a cell that contains a single set of
Ans. Pyruvic acid produced through glycolysis is
chromosomes. (n)
converted into other organic acids or alcohol
*(6) Which type of cellular respiration performs
with the help of some enzymes. This is called
complete oxidation of glucose?
fermentation.
(Can you tell - Textbook Page no. 16)
(8) Lipids
Ans. Aerobic respiration performs complete oxidation
Ans. The substances formed by specific chemical bonds
of glucose.
between fatty acids and alcohol are called as lipids.
*(7) Which cell organelle is necessary for complete
(9) Homologous Chromosomes
oxidation of glucose?
Ans. A pair of chromosomes that are similar by shape and (Can you tell; Textbook Page no. 16)
organisation are called homologous chromosomes.
Ans. Mitochondria is necessary for complete oxidation
(10) Vitamins
of glucose.
Ans. Vitamins are a group of heterogeneous compounds
*(8) What is the importance of balanced diet for our
of which each is essential for proper operation of
body? (Can you recall - Textbook Page no. 12)
various processes in the body.
Ans.
(11) Anaerobic Respiration:
Ans. Anaerobic Respiration is the process of producing (i) Balanced diet is vital for the body and its systems
energy from foodstuff without the help of oxygen. to function properly.
Life Processes In Living Organisms Part - 1 29

(ii) It will help to maintain a healthy weight, reduce *(15) How the individual of a species is formed from
body fat, provide your body with energy, existing one of same species?
promote good sleep, helps to fight diseases and (Can you tell - Textbook Page no. 17)
generally make you feel better. Ans.
*(9) What is the importance of digestive juices in the (i) New individual of a species is formed from the
digestive system? existing one of the same species by the process of
(Can you recall - Textbook Page no. 12) reproduction.
(ii) It involves cell division - mitosis and meiosis.
Ans.
*(16) Whether the gametes are diploid or haploid?
(i) Digestive juices create conditions required for
Why? (Use your Brain power-Textbook Page No. 20)
digestion of food.
Ans. The gametes are haploid as they have half the
(ii) Digestive juices contain enzymes which break number of chromosomes (n).
down different components of food like *(17) How are the haploid cells formed?
carbohydrates proteins and fats, so that the (Use your Brain power-Textbook Page No. 20)
essential nutrients are absorbed and properly
Ans. Haploid cells are formed by a type of cell division
utilized by the body. called meiosis.
*(10) What is the role of circulatory system in energy *(18) What is the importance of haploid cells?
production? (Can you recall - Textbook Page no. 12) (Use your Brain power-Textbook Page No. 20)
Ans. The circulatory system allows the transport of Ans. When haploid cells or gametes fuse, they form a
energy rich substances and oxygen in the blood to diploid zygote so that the chromosome number in
the body’s cells so that they can produce energy the organism is restored.
for their functioning. *(19) From where do we obtain lipids?
(Can you recall - Textbook Page no. 16)
*(11) What happens to the cells of injured tissue?
Ans. We obtain lipids from milk, butter, cheese, oil,
(Can you tell - Textbook Page no. 17)
ghee, meat, nuts and oilseeds, etc.
Ans. The cells of the injured tissue start dividing and
Q.2.3. Write short notes on:
increase in numbers to repair and heal the injured
(1) Adenosine triphosphate (ATP)
tissue.
Ans.
*(12) What is the source of proteins? What are they
(i) Adenosine triphosphate (ATP) is energy rich
made up of?
molecule and energy is stored in the bonds by
Ans. which phosphate groups are attached to each other.
(i) Sources of proteins: Milk and milk products, (ii) These molecules are stored in the cells as per need.
eggs, meat, legumes and pulses.
(iii) Chemically, ATP is a triphosphate molecule formed
(ii) Proteins are made up of amino acids. from Adenosine ribonucteoside.
*(13) Whether new cells are formed during healing of (iv) It contains a nitrogenous compound adenine,
wound? (Can you recall - Textbook Page no. 17) pentose sugar ribose and three phosphate groups.
(v) As per the need, energy is derived by breaking the
Ans.
phosphate bond of ATP. Hence, ATP is called as the
Yes, the injured cells are restored by the formation energy currency of the cell.
of new cells.
(2) Proteins
*(14) Which system is in action for removal of waste Ans.
materials produced in human body. (i) Proteins are the macromolecules formed by
(Can you recall - Textbook Page no. 12) bonding together many amino acids.
Ans. Excretory system in is action for removal of waste (ii) Proteins of animal origin are called as first class
materials produced is human body. proteins.
30 Master Key Science and Technology Part-2 (Std. X)

(iii) We get 4 kcal of energy per gram of proteins. of which each is essential for proper operation of
(iv) Amino acids are obtained after digestion of various processes in the body.
proteins. (ii) These are main six types of vitamins, namely A,
(v) These amino acids are absorbed in the body and B, C, D, E and K.
transported upto each organ and cell via blood.
(iii) Out of these A, D, E and K are fat soluble whereas
(vi) From these amino acids, organs and cells produce
B and C are water soluble.
various proteins necessary for themselves and
the whole body. Eg. Melanin, Keratin, Ossein, (iv) Vitamins like riboflavin (vitamin B2) and
hemoglobin, etc. nicotinamide (vitamin B3) are necessary for
(3) Vitamins production of FADH2 and NADH2 respectively
Ans. which are produced in processes like glycolysis
(i) Vitamins are a group of heterogeneous compounds and Kreb’s cycle.

Q.2.4. Distinguish between:

*(1) Glycolysis and TCA cycle
Ans. Glycolysis TCA cycle

(i) Glycolysis occurs in the cytoplasm (i) TCA cycle occurs in the mitochondria

(ii) Two molecules each of pyruvic acid, ATP, (ii) Molecules of CO2, H2O, NADH2 and FADH2 are
NADH2 and water are formed formed.

(iii) It is also called as EMP pathway. (iii) It is also called as Kreb’s cycle.

(iv) No carbon dioxide is released. (iv) Carbon dioxide is released.

*(2) Mitosis and Meiosis

Ans. Mitosis Meiosis

(i) Mitosis takes places in the somatic cells. (i) Meiosis takes place in the germ cells.

(ii) Occurs in both sexually as well as asexually (ii) Occurs only in sexually reproducing organisms.
reproducing organisms.

(iii) The cell divides only once. (iii) There are two cell divisions, Meiosis I and Meiosis
II.

(iv) Chromosome number remains constant at (iv) Chromosomal number is reduced from diploid to
the end of mitosis. haploid, at the end of meiosis.

*(3) Aerobic and Anaerobic respiration

Ans. Aerobic respiration Anaerobic respiration

(i) Process occurs in the presence of oxygen. (i) Process occurs in the absence of oxygen.

(ii) Common in all higher plants and animals. (ii) Common in certain microorganisms but very
rare in all higher plants and animals.
(iii) Energy is released in greater amounts in (iii) Energy is released in lesser amounts in the form
the form of ATP. of ATP.
(iv) Glucose is completely oxidised. (iv) Glucose is incompletely oxidised.
(v) The end products are CO2 and water. (iv) The end products are CO2 and organic acids or
alcohol.
Life Processes In Living Organisms Part - 1 31

(4) Telophase and Prophase

Ans. Telophase Prophase

(i) It is the last stage of karyokinesis. (i) It is the first stage of karyokinesis.
(ii) Nuclear membrane is formed around each (ii) Nuclear membrane starts disappearing.
set of chromosome.
(iii) Nucleolus starts being visible again. (iii) Nucleolus starts to disappear.
(iv) Chromosomes are present at the opposite (iv) Chromosomes are randomly arranged in the cell.
poles of the cell.

Q.2.5. Give scientific reasons : (ii) To perform aerobic respiration, higher plants and
*(1) Oxygen is necessary for complete oxidation of animals perform aerobic respiration.
glucose. (iii) Cases when oxygen gets depleted these organisms
respire anaerobically to obtain energy.
Ans.
(iv) Therefore, sometimes higher plants and animals
(i) Aerobic cellular respiration is the process by
too perform anaerobic respiration.
which cells use oxygen to help them convert
*(5) Kreb’s cycle is also known as citric acid cycle.
glucose into energy.
Ans. Kreb’s cycle is also known as critric acid cycle
(ii) Without oxygen, glucose will be incompletely
because citric acid is the very first stable product
oxidized and very less energy (2ATP) is produced.
generated, in this cycle.
(iii) In the presence of oxygen glucose is completely
(6) We feel tired when we exercise.
oxidised to produce more energy (38 ATP).
Ans.
(iv) Therefore, oxygen is necessary for complete
(i) Our muscle cells perform anaerobic respiration
oxidation of glucose.
while performing the exercise.
*(2) Fibers are one of the important nutrients.
(ii) Due to this, less amount of energy is produced
Ans. in our body and lactic acid accumulates due to
(i) We cannot digest fiber but they help in the which we feel tired.
digestion of other substances and egestion of (7) Water is an essential nutrient.
undigested substances. Ans.
(ii) Hence, fibers are one of the important nutrients. (i) There is about 65-70% water in our body.
*(3) Cell division is one of the important properties (ii) Each cell contains 70% water weight by weight.
of cells and organisms. (iii) Blood plasma also contains 90% of water.
Ans. (iv) Functioning of cells and thereby whole body gets
(i) Due to the property of cell division only, a new disturbed even if there is a little loss of water
organism is formed from the existing one, a from the body.
multicellular organism grows up and emaciated (v) Hence, water is an essential nutrient.
body can be restored. *(8) Many times, we experience dryness in mouth.
(ii) It is required for wound healing and formation of (Use your Brain power - Textbook Page no. 17)
blood cells. Ans. We experience dryness in the mouth due to
drinking less fluids or loss of water from the
(iii) Hence, cell division is one of the important
body resulting in dehydration.
properties of cells and organisms.
*(9) Oral rehydration solution (salt-sugar-water) is
*(4) Sometimes, higher plants and animals too
frequently given to a person experiencing loose
perform anaerobic respiration. motions.
Ans. (Use your Brain power - Textbook Page no. 17)
(i) The process of respiration yields energy which Ans.
occurs by the oxidation of foodstuffs. (i) When loose motions occur, essential fluids and
32 Master Key Science and Technology Part-2 (Std. X)

salts are lost from the body causing dehydration Q.3.1. Draw a neat labelled diagram of:
and must be quickly replaced. *(1) Human respiratory system. (Observe, Textbook
(ii) ORS drink contains the main elements that are Page No. 13)
lost from the body during loose motions. Hence, Ans.
ORS solution is frequently given to person
experiencing loose motions. Nasal Cavity

*(10) We sweat during summer and heavy exercise. Oral Cavity

(Use your Brain power - Textbook Page no. 17) Pharynx
Ans. Larynx
(i) Human beings are warm-blooded. We need
Right Lung
to maintain a constant body temperature Left Lung
irrespective of the surrounding conditions. Diaphragm
(ii) In summer and during heavy exercise, lot of heat
is generated which raises our body temperature.
(iii) Sweating leads to loss of excess body heat and Alveoli
brings down the body temperature to normal.
(iv) Therefore, we sweat during summer and heavy
Fig. 2.1: Human Respiratory system
exercise.
(2) Mitochondria and Tri-carboxylic acid cycle.
*(11) Many times, you cannot eat hot food due to
inflammation / ulceration in mouth. Ans.
(Think - Textbook Page no. 17) Pyruvic acid Fatty acids
Ans. Acetyl COA

(i) One of the reason for ulcer is deficiency of

Vitamin B12. NADH NADH CO2
Kreb’s

(ii) The inflammation / ulceration in mouth makes

cycle

it painful and irritate the injured cells causing

FADH2
CO2
NADH

discomfort. Outer Mitochondrial

Membrane Inner
(iii) Therefore many times, you cannot eat hot food Membrane
matrix
due to inflammation / ulceration in mouth.
Fig. 2.2: Mitochondria and Tri-carboxylic acid cycle
*(12) Some persons experience difficulty in night
vision since their childhood or adolescence. Q.3.2. Answer the following :
(Think - Textbook Page no. 17) *(1) Explain glycolysis in detail.
Ans.
Ans.
(i) The difficulty in night vision is called night
Glucose→Pyruvic acid→Acetyl‒CoA→CO2+H2O+ Energy
blindness.
(glycolysis) (Kreb’s cycle)
(ii) This is due to the deficiency of vitamin A.
(i) Process of glycolysis occurs in cytoplasm.
(iii) As a result, some persons experience difficulty is
(ii) A molecule of glucose is oxidized step by step in
night vision.
the process and two molecules of each i.e. pyruvic
Q.2.6. What would happen if : acid, ATP, NADH2 and water are formed.
(1) Soil with seeds is submerged under water (iii) Molecules of pyruvic acid formed in this
during germination. process are converted into molecules of
Ans. If the soil is submerged under water during Acetyl - Coenzyme A.
germination, seeds perform anaerobic respiration. (iv) Two molecules of NADH2 and two molecules of
(2) There is insufficient amount of carbohydrates in CO2 are released during this process.
body due to exceptional conditions like fasting *(2) How are the various processes occurring in the
and hunger. human body controlled? In how many ways?
Ans. If there is insufficient amount of carbohydrates (Can you recall - Textbook Page no. 12)
in body due to exceptional conditions like fasting Ans.
and hunger, then lipids and proteins are used for (i) Various organ systems are continuously
energy production. performing their functions in human body.
Life Processes In Living Organisms Part - 1 33

(ii) Along with the various systems like digestive, *(7) What is respiration? How does it occur?
respiratory, circulatory, excretory and control (Can you recall - Textbook Page No. 12)
systems, different external and internal organs Ans.
are performing their functions independently but (i) The process of release of energy by oxidation of
through a complete co-ordination. food is called as respiration.
(iii) This is controlled in two ways - Nervous control (ii) In living organisms, respiration occurs at two
by nervous system and chemical control by the levels - body and cellular level.
hormones secreted by the endocrine glands. (iii) In case of body level, oxygen and carbon
*(3) In terms of chemistry what happens actually, dioxide are exchanged between the body and
when a molecule is oxidized? surrounding.
(Can you tell - Textbook Page no. 13) (iv) In case of cellular level, food is oxidized either with
Ans. In terms of chemistry when a molecule is oxidized or without the help of oxygen to release energy.
it gains oxygen or loses electrons or hydrogen. *(8) How are the food stuffs and their nutrient
*(4) Do the plants get injured when we pluck the contents useful for body?
(Can you recall - Textbook Page No. 12)
flowers? How are those wounds healed?
(Can you tell - Textbook Page no. 17) Ans. The following table shows how food stuffs and
Ans. their nutrient contents are useful for body.

(i) Yes, plants get injured when we pluck flowers. Nutrients Health
Food stuff
(ii) The wounds are healed by formation of new cells present benefits
by cell division. (1) Fruits and carbohydrates, reduce risk
*(5) How does the growth of any living organism vegetables vitamins, of chronic
occur? Does the number of cells in their body fibers and diseases,
increase? If yes, how? sugar. build
(Can you tell - Textbook Page no. 17) immunity,
prevent
Ans.
constipation.
(i) Growth of any living organism occurs due to cell
division. (2) Wheat carbohydrates, promote
flour proteins, healthy
(ii) Yes, the number of cells in their body increase.
vitamins and digestion
(iii) The number of cells increases by the process of minerals. support
mitosis. metabolism,
*(6) What is the shape of a chromosome? Give its provide
name in the figure. energy.
(Can you recall - Textbook Page no. 18) (3) Honey carbohydrates, build
Ans. The shape of the chromosome is metacentric. (as vitamins, immunity.
the centromere is in the centre) minerals and
antioxidants.
(4) Milk carbohydrates, maintain
proteins, fats, healthy blood
p Arm
vitamins, pressure,
minerals, etc. provides
Centromere energy,
supports
growth.
q Arm
*(9) Which different functions are performed by
muscles in body?
DNA (Can you recall - Textbook Page no. 12)
Ans.
(i) Muscles bring about movement of arms and legs,
running, speaking, walking etc.
Fig. 2.3: Structure of chromosome
34 Master Key Science and Technology Part-2 (Std. X)

(ii) Muscles also bring about movement of eyelids, Ans.

passage of food through the alimentary canal,
contraction and relaxation of blood vessels. Lipids Carbohydrates Proteins
(iii) Cardiac muscles bring about contraction and
relaxation of the heart.
Fatty acids Glycolysis Amino acids
*(10) Why may be the players seen consuming these
food stuffs? (Use your Brain power, Textbook Pg. 12)
Ans. Pyruvic acid
(i) Players are in need of continuous energy during
games. Acetyl - CoA
(ii) Carbohydrates (glucose) are major and quick
source of energy. Kreb’s cycle
(iii) Hence, players are seen consuming food stuffs
rich in carbohydrates during breaks of the game.
CO2 + H2O + Energy
Q.3.3. Complete the given table:
(1) Anaerobic respiration in living organisms/ cells
(3) Give examples of different proteins formed in
Glucose various parts of our body from amino acids:
Ans.

Glycolysis Body Part Protein

Pyruvic acid Pyruvic acid
Skin Melanin, Keratin
Bones Ossein
Fermentation Pyruvic acid Fermentation
Various proteins of cell
Cells
membrane, various enzymes
Alcohol Fermentation Lactic acid
Pancreas Insulin, Trypsin
Pituitary gland Various hormones
Different
Products Muscles Actin and Myosin
e.g. Vinegar, Erythrocytes, Blood Haemoglobin, antibodies
Yeast Vitamins, etc. Muscle cells,
Q.3.4. Observe the figure and answer the following
questions.
Various
Microbes (1)
A
*(2) How energy is formed from oxidation of
carbohydrates, fats and protein? Correct the
B
diagram given below.

Pyruvic acid

Acetyl Co-Enzyme A (a) Label the parts A and B.

Ans. (A) Centriole (B) Chromatids
(b) Identify the phase of cellular division.
Ans. The phase is Anaphase of mitosis cell division.
Lipids Glycolysis Amino acids (c) What phase comes before this phase?
Ans. Metaphase is before this phase.
Proteins Kreb’s cycle Fats (d) Define the term Karyokinesis.
Ans. Karyokinesis means division of the nucleus.
Life Processes In Living Organisms Part - 1 35

(2) Glucose Pyruvic acid Alcohol Yeast Ans.

(1) Somatic cells and stem cells divide by mitosis.
A B
(2) Mitosis is completed through two main steps,
(a) Name the processes A and B.
(a) Karyokinesis (nuclear division)
Ans. A - Glycolysis
B - Fermentation (b) Cytokinesis (cytoplasmic division)
(b) What type of energy production is shown above? (3) Karyokinesis is completed through 4 steps.
Ans. Anaerobic energy production. (a) Prophase : (i) Condensation of basically thin
(c) Give one point of difference between yeast cells thread - like chromosomes starts.
and muscle cells in relation to the above process. (ii) Due to this, they become short and thick and
Ans. In yeast cell, the end product is alcohol and in they start to appear along with the pairs of sister
muscle cells, the end product is Lactic acid.
chromatids.
Q.4. Answer in detail : (iii) Centrides duplicate and each centride moves to
*(1) With the help of suitable diagrams explain the opposite poles of the cell.
mitosis in detail.
(iv) Nuclear membrane and nucleous start to
Ans.
disappear.
(b) Metaphase : (i) Nuclear membrane completely
disappears. Chromosomes complete their
Chromosomes Genetic Material condensation and become clearly visible.
Cell membrane (ii) All chromosomes are arranged parallel to
Nuclear membrane equatorial plane (central plane) of the cell.
Cytoplasm
(iii) Special type of flexible protein fibres (spindle
4n
fibres) are formed between centrioles and
centromere of each chromosome.
(c) Anaphase : (i) Centromeres split and thereby
Prophase Metaphase sister chromatids of each chromosome separate
and they are pulled apart in opposite directions
Anaphase with the help of spindle fibres.
2n (ii) Separated sister chromatids are called daughter
chromosomes.
Telophase (iii) In this way, each set of chromosomes reach at
two opposite potes of the cell.
(d) Telophase : (i) The chromosoms which have
reached at opposite poles of the cell now start
to decondense due to which they again become
Fig. 2.4. Mitosis
thread like thin and invisible.
(ii) Nuclear membrane is formed around
each set of chromosomes reached at poles.
(iii) Thus two daughter nuclei are formed in a cell.
(iv) Nucleolus also appears in each daughter nucleus.
Spindle fibres completely disappear.
(4) In this way, karyokinesis completes and
cytokinesis begin.
(5) Cytokinesis : The cytoplasm divides by
cytokinesis and two new cells are formed which
Fig. 2.5 Cytokinesis
are called as daughter cells. In this process, a
36 Master Key Science and Technology Part-2 (Std. X)

notch is formed at the equatorial plane of the cell condense and shorten. Nucleolus and nuclear
which deepens gradually and thereby two new membrane completely disappear, spindle fibres
cells are formed. begin to appear.
(6) However, in case of plant cells, instead of *(3) How all the life processes contribute to the
the notch, a cell plate is formed exactly along growth and development of the body?
the midline of the cell and thus cytokinesis is Ans.
completed.
(i) Various organ systems are continuously
*(2) With the help of suitable diagrams, explain the performing their functions in human body.
five stages of prophase I of meiosis. (ii) Along with the various systems like digestive,
Ans. (i) Prophase I is the most important stage of respiratory, circulatory, excretory and control
meiosis and differs considerably from the system, different external and internal organs are
prophase of mitosis. (ii) It is divided into 5 stages performing their functions independently but
leptotene, zygotene, pachytene, diplotene and through complete co-ordination.
diakinesis. (iii) It involves essentially the crossing (iii) This overall system is in need of continuous
over and recombination of genetic material source of energy.
between non sister chromatids. (iv) Besides, it is co-ordinated by the control system
of the body i.e. each life process contributes in its
own way in the process of energy production.
(v) Thus, all life processes contribute to the growth
and development of the body.
*(4) Explain the Kreb’s cycle with reaction.
1 2 3 Ans.
(i) Both molecules of acetyl-CoA produced
from pyruvic acid (from glycolysis) enter the
mitochondria.
(ii) Cyclic chain of reactions called as tricarboxylic
acid cycle is operated on it in the mitochondria.
4 5
(iii) Acetyl part of acetyl-CoA is completely oxidized
Fig. 2.6 Prophase - I (1 - 5) through this cyclical process and molecules of
(iv) Phase - I - Leptotene : In this stage already CO2, H2O, NADH2, FADH2 are formed.
replicated chromatin network condenses and (iv) Net reaction of Kreb’s cycle:
start converting into long thin thread like Acetyl-CoA + 3NAD++ → 2CO2 + CoA + 3(NADH + H+)
chromosomes. FAD + GDP + Pi + 3H2O + FADH2 + GTP)
(v) Phase - II - Zygotene : It this stage homologous
chromosomes come closer to each other. This Acetyl-CoA
pairing is called ‘Synapsis’.
(vi) Phase - III - Pachytene : Sister chromatids
become visible in this stage. Crossing over Citric Acid
FADH2
occurs between non-sister chromatids of the
homologous chromosomes. The crossing over is
called as ‘Chiasma or Chiasmata’ and this leads
to genetic recombination causing variations. H2O NADH2
(vii) Phase - IV - Diplotene : In this stage, recombined
sister chromatids start repelling. Nucleolus and
CO2
nuclear membrane start disappearing.
(viii) Phase - V - Diakinesis : Chromosomes further Fig. 2.9 Kreb’s Cycle
Life Processes In Living Organisms Part - 1 37

(5) What are lipids? What is their role in our body? (iv) Glycolysis and fermentation are two steps of
Ans. anerobic respiration.

(i) The substance formed by specific chemical bond (v) Pyruvic acid produced through glycolysis is
converted into other organic acids or alcohol
between fatty acids and alcohol are called as
with the help of some enzymes. This is called as
lipids.
fermentation.
(ii) Digestion of lipids is their conversation into fatty
(vi) Some higher plants, animals and aerobic
acids and alcohol. microorganisms also perform anaerobic
(iii) Fatty acids are absorbed and distributed respiration instead of aerobic respiration if there
everywhere within the body. is depletion of oxygen level in the surrounding.
(iv) From these fatty acids, different cells produce (vii) Example: Seeds perform anaerabic respiration
various substances necessary to themselves. if the soil is submerged under water during
germination.
(v) For example, phospholipids which are essential
for producing plasma membrane are formed (viii) Similarly, our muscle cells also perform anaerobic
from fatty acids. respiration while performing the exercise.
(ix) Due to this less amount of energy is produced
(vi) Fatty acids are also used for producing hormones
in our body and lactic acid accumulates in the
like progesterone, estrogen, testosterone,
muscles due to which we feel tired.
aldosterone, etc and the covering around axons
(7) Explain with the help of a diagram - ATP is
of nerve cells.
called as the energy currency of the cell.
(vii) We get 9 Kcal of energy per gram of lipids.
OR
(viii) Excess of lipids are stored in adipose connective Explain the importance of ATP in a cell with a
tissue in the body. diagram.
(6) Describe Anaerobic respiration. Ans.
Ans. (i) ATP (Adenosine Tri-phosphate) is an energy rich
(i) Some organisms cannot live in presence of molecule.
oxygen. E.g. Many bacteria. (ii) Energy is stored in the bonds by which phosphate
(ii) Such living organisms have to perform anaerobic groups are attached to each other.
respiration for energy production. (iii) As per energy need, energy is derived by breaking
the phosphate bond of ATP.
(iii) Glucose is incompletely oxidised and less amount
of energy is obtained in anaerobic respiration. (iv) Hence, ATP is called as the energy currency of
the cell.

ATP ADP

Adenine Adenine
Phosphate bonds with
more energy
Inorganic Phosphate

Ribose Ribose
Mitochondrial
Energy released
matter
Fig. 2.8 : Energy currency of the cell

vvv
38 Master Key Science and Technology Part-2 (Std. X)

ASSIGNMENT - 2
Time : 1 hour Marks : 20

Q.1. (A) Answer the following: (3)

(1) Fill in the blank: Our muscle cells perform .................. type of respiration during exercise.
(2) Write the full form of NADH.
(3) Name the water soluble vitamins.
Q.1. (B) Choose and write the correct option: (2)
(1) Water content of Blood Plasma is .................. .
(a) 70% (b) 90% (c) 65% (d) 50%
(2) In which part of cell, electron transfer chain reaction occurs?
(a) Cytoplasm (b) Mitochondria (c) Nucleus (d) Golgi body
Q.2. Answer the following : (Any 2) (4)
(1) Complete the diagram.

(2) Give scientific reason: We feel tired when we do exercise.
(3) Distinguish between : Anaphase and Telophase.
Q.3. Answer in brief: (Any 2) (6)
(1) Explain the Metaphase and Telophase of Mitosis.
(2) What are proteins ? What is their role in our body?
(3) How are the various processes occurring in the human body controlled? In how many ways?
Q.4. Answer in detail : (Any 1): (5)
(1) Explain glycolysis and Kreb’s cycle in detail.
(2) With the help of a suitable diagram explain five stages of prophase I - in meiosis.
vvv
 3 Life Processes in Living Organisms Part - 2

CONCEPT MAP
(1) Reproduction

Sexual Reproduction Asexual Reproduction

Plants Humans
Unicellular Organisms Multicellular Organisms

Androecium Gynoecium Male Female

(Pollen grains) (Ovules) (Sperms) (Ova) Binary Multiple Budding
fission fission
Gamete formation and fertilization

Simple binary Transverse Longitudinal

fission binary fission binary fission
eg. Amoeba eg. Paramoecium eg. Euglena

Fragmentation Regeneration Budding Vegetative propoagation Spore formation

eg. Spirogyra eg. Planaria eg. Hydra eg. Bryophyllum eg. Mucor

(2) Reproduction and Modern Technology

In vitro fertilization Surrogacy Sperm Bank /

(IVF) Semen Bank

(3) Flower

Essential whorls Non essential whorls

Stamen Carpel Calyx Corolla

Anther Filament Stigma Style Ovary

(39)
40 Master Key Science and Technology Part-2 (Std. X)

(4) Menstrual Cycle

FSH starts follicle development inside ovary

Developing follicle produces estrogen

Development of endometrium

Follicle development completes LH makes oocyte release (ovulation)

Remaining forms corpus Luteum

Progesterone is produced

Implantation of embryo

If no implantation, corpusluteum becomes corpus albicans

Endometrium degenerates + unfertilized ovum

Released out of vagina along with bleeding

Points to Remember:
� Formation of new organisms of same species by earlier existing organism is called as reproduction.
� Reproduction is one of the various important characters of living organisms.
� It is one of the reasons for evolution of species.
� Reproduction occurs mainly by two methods : Asexual reproduction and Sexual reproduction.
� Asexual Reproduction:
- Process of formation of new organism by an organism of same species without involvement of gametes
is called as asexual reproduction.
- Absence of genetic recombination is a disadvantage, whereas fast process is advantage of this reproductive
method.
� Asexual reproduction in unicellular organisms:
� Binary fission
- In this process, the parent cell divides to form two similar daughter cells.
- Binary fission occurs either by mitosis or amitosis.
- Axis of fission/division is different in different protists.
� Multiple Fission
- Asexual reproduction by multiple fission is performed by Amoeba and other similar protists.
- Many nuclei are formed by repeated nuclear division in the cyst.
- It is followed by cytoplasmic division and thus many amoebulae are formed.
Life Processes in Living Organisms Part - 2 41

- Cyst breaks open on arrival of favourable condition and many amoebulae are released.
� Budding
- Asexual reproduction occurs by budding in yeast - unicellular fungus.
- Yeast reproduces by mitotic division.
- A small bulge appears on the surface of the parent cell.
- This bulge is actually a bud. One of the two daughter nuclei enters this bud.
- After sufficient growth, bud separates from the parent cell and starts to live independently as a daughter
yeast cell.
� Asexual reproduction in multicellular organisms:
� Fragmentation
- In this type of reproduction, the body of parent organism breaks into many fragments and each fragment
starts to live as an independent new organism.
e.g. Spirogyra and Sycon
� Regeneration
- Under certain situation, an animal- Planaria breaks up its body into two parts and thereafter each part
regenerates remaining part of the body. Thus, two new Planaria are formed. This is called as Regeneration.
� Budding:
- Hydra reproduces with this process under specific conditions.
- An outgrowth is formed by repeated division of regenerative cells of body wall.
- This bud formed grows progressively and finally forms small Hydra.
� Vegetative Propagation:
- Reproduction in plants with the help of vegetative parts like root, stem, leaf and bud is called as
vegetative reproduction. e.g. Bryophyllum, carrots and raddish.
� Spore formation:
- Fungi like mucor have filamentous body. They have sporangia.
- Once spores are formed sporangia bursts and spores are released.
- Spores germinate in moist and warm place and new fungal colony is formed.
� Sexual Reproduction - Sexual reproduction always occur with the help of two germ cells : female gamete and
male gamete.
� Two main processes occur in the sexual reproduction
- Gamete formation - Haploid gametes are formed by meiosis.
- Fertilization - A diploid zygote is formed in this process by union of haploid male and female gametes.
This zygote divides by mitosis and embryo is formed. The embryo develops to form new individual.
� Sexual reproduction in plants:
- A flower is the structural unit of sexual reproduction in plants.
- A flower consists of four floral whorls as calyx, corolla, androecium and gynoecium.
- Androecium and gynoecium are called as essential whorls.
- Calyx and corolla are accessory whorls.
- Androecium is male whorl and its members are called as stamens.
- Gynoecium is female whorl and its members are called as carpels.
- Ovary is present at the basal end of carpel.
- A hollow style comes up from the ovary.
- Stigma is present at the tip of style.
- Ovary contains one or many ovules.
- Embryo sac formed in each ovule consists of a haploid egg cell and two haploid polar nuclei.
42 Master Key Science and Technology Part-2 (Std. X)

- Transfer of pollen grains from anther to stigma is called as Pollination.

- Pollination occurs with the help of biotic and abiotic agents.
- Pollen grains germinate and fall on sticky stigma.
- Pollen tube carries male gametes which reaches the embryo sac via style.
- One male gamate unites with egg cell to form Zygote.
- This process is called fertilization.
- Second male gamate unites with two polar nuclei and endosperm is formed. This process is called double
fertilization.
� Sexual reproduction in human beings:
� Human male reproductive system:
- Male reproductive system of human consists of testes, various ducts and glands.
- Testes present in the scrotum outside the abdominal cavity, contains numerous seminiferous tubules.
- Germinal epithelium present in tubules divide by meiosis to produce sperms.
- Sperms travel through sequence from testes, vas eferens, epididymis, vas deferens, ejaculatory duct
and lastly to urinogenital duct.
- Seminal vesicles secrete their secretion in ejaculatory duct and prostate gland and cowper’s glands secrete
their secretion in urinogenital duct.
- Semen is a mixture of sperms and these secretions.
- Semen is ejaculated through penis.
� Human female reproductive system
- Female reproductive system includes a pair of ovaries, a pair of oviducts, single uterus and a vagina.
- A pair of bulbo-urethral gland is present.
- An ovum is released every month in the abdominal cavity alternately from each ovary.
- The oviduct which is funnel shape has a free end through which the oocyte enters it.
- Cilia present on the inner surface of the oviduct push the oocyte towards the uterus.
� Gamete formation
- Both gametes i.e. sperm and ovum are formed by meiosis.
- Sperms are produced in testes of men from beginning of maturation till death.
- 2 - 4 million immature oocytes are present in the ovary from the time of birth.
- An oocyte matures and is released every month and stops at the age of menopause (i.e. 45 years)
� Fertilization
- Formation of zygote by union of sperm and ovum is called as fertilization.
- It is internal in humans.
- Semen is ejaculated in vagina during copulation and sperms start their journey from vagina-uterus-
oviduct.
- One of the few million sperms fertilize the only ovum present in the oviduct.
- From the age of puberty upto menopause, an ovum is released every month.
- Only 400 oocytes are released and rest undergo degeneration.
� Development and Birth
- The zygote formed after fertilization in the oviduct, undergoes repeated mitotic divisions and embryo
is formed.
- Embryo is then implanted in uterus for further development.
- Placenta is formed for supply of food material from mother to the body.
- Embryonic development is completed approximately within nine months after the fertilization.
Life Processes in Living Organisms Part - 2 43

� Menstrual cycle
- Female reproduction system undergoes some changes at puberty and those changes repeat at the interval
of every 28 - 30 days. This repetitive changes are called as menstrual cycle.
- It is controlled by four hormones : follicle stimulating hormone (FSH), luteinizing hormone [LH], estrogen
and progesterone.
- One of the follicles in the ovary starts to develop along with oocyte in presence of FSH.
- This developing follicle secretes estrogen.
- Endometrium of uterus starts to develops in presence of estrogen.
- Developed follicle bursts in presence of LH and oocyte is released. This is called as ovulation.
- Remaining tissue of follicle forms the corpus luteum.
- Corpus luteum secrets Progesterone.
- Endometrial glands secrete their secretion in presence of progesterone and such endometrium is ready for
implantation.
- If oocyte is not fertilized within 24 hours, corpus luteum becomes inactive and transforms into corpus
albicans and secretion of estrogen and progesterone stops.
- Endometrium degenerates in absence of these hormones.
- Tissues of endometrium and unfertilized ovum are discarded through vagina accompanied with
continuous bleeding. This is called menstruation and continues for five days.
- Menstrual cycle is a natural process.
� Reproduction and modern technology
- Many couples cannot have child due to various reasons.
- But now with the help of advanced medical techniques like IVF, Surrogacy, Sperm bank, the childless
couples can have a child.
- In IVF, fertilization is brought about in a test tube and embryo formed is implanted in uterus of woman at
appropriate time.
- In surrogacy, oocyte is collected from woman having problem in implantation and sperms are collected
from her husband and fertilized in the test tube.
- The embryo thus formed is implanted in uterus of some other woman having normal uterus. Such a
woman is called as a surrogate mother.
- Just as women, men also face issue with sperm production.
- A new concept of sperm bank has been introduced.
- Semen is collected from desired men and stored in the sperm bank
� Twins.
- When two embryos develop simultaneously in the same uterus and thus two offsprings are delivered
simultaneously. Such offsprings are called as Twins.
- They are of two types: monozygotic twins and dizygotic twins.
- Monozygotic twins are exactly similar to each other and their gender is also same.
- Dizygotic twins are formed from two separate oocytes and sperms so they are genetically different and
may be of same or different gender.
� Reproductive Health
- A person’s state of being physical, mental and social strength is called health.
- Occurrence of menstrual cycle is related with reproductive and overall health of women.
- Some problems regarding reproductive health may arise in men too.
- Therefore, it is essential to maintain cleanliness of their genitals in order to protect themselves from
various sexual diseases, syphilis and gonorrhea which are caused by bacteria.
44 Master Key Science and Technology Part-2 (Std. X)

(22) Many flowers have stalk for support called as

MASTER KEY QUESTION SET - 3 .
Q.1. (A) 1. Fill in the blanks and rewrite the (23) Members of gynoecium are called as
completed statement: (24) is present at the tip of the style.
*(1) In humans, sperm production occurs in the organ (25) Testes contain numerous .
.
(26) present in semiinferous tubules
*(2) In humans, chromosome is divide by meiosis to produce sperms.
responsible for maleness.
(27) is the stoppage of functioning of
*(3) In male and female reproductive system of female reproduction system.
human, gland is same.
(28) The two main methods of reproduction are
*(4) Implantation of embryo occurs in . and .
*(5) type of reproduction occurs without (29) Cell organelles like and
fusion of gametes. perform asexual reproduction by binary fission.
*(6) Body breaks up into several fragments and each (30) A flower is called as if both whorls
fragment starts to live as a new individual. This i.e., androecium and gynoecium are present in
is type of reproduction. the same flower.
*(7) Pollen grains are formed by division (31) Formation of zygote by union of sperm and ovum
in locules of anthers. is called as .
(8) Yeast cell produces two daughter nuclei by (32) An organ called as is formed for
division.
the supply of food material to the embryo in the
(9) The zygote divides by mitosis and is uterus.
formed.
(33) Endometrium of the uterus starts to develop or
(10) breaks open on arrival of favourable regenerate under the effect of .
conditions and many amoebulae are released.
(34) Corpus luteum secrets the hormone .
(11) and digestive cavity of the budding
(35) In technique, fertilization is brought
Hydra are in continuity with those of parent
about in test tube.
Hydra.
(36) Women who have problems in implantation of
(12) A is formed in the process of
embryo in uterus can take the help of modern
fertilization by union of hyploid male and female
technique called .
gametes.
(37) Twins formed from single embryo are called
(13) is male whorl and its members are
twins.
called as stamens.
(38) If embryonic cells are divided into two groups,
(14) Embryonic development is completed
8 days after the zygote formation, there is high
approximately within after the
possibility of formation of .
fertilization.
(39) A person’s state of physical mental and social
(15) Encysted Amoeba or any other protist is called
strongness is called as .
(40) If oocyte is not fertilized within 24 hours, corpus
(16) Reproduction in plants with the help of parts like
luteum becomes inactive and transforms into
root, stem, leaf and bud is called as .
.
(17) Planaria reproduces by .
(41) In plants, second male gamete fuses with two
(18) Fungi like have filamentous body.
polar nuclei to form .
(19) In , chromosome number is reduced
(42) Testes are present in the outside the
to half.
abdominal cavity.
(20) is the structural unit of sexual
(43) is formed of sperms and the
reproduction in plants.
secretions of prostate glands, cowper’s glands
(21) are called essential whorls. and seminal vesicles.
Life Processes in Living Organisms Part - 2 45

(44) The action of giving birth to young baby is called (3) Hydra : Budding : : Bryophyllum : :
. Ans. Vegetative propagation - Reproduction in
(45) All the organs of male reproductive system Hydra occurs via budding, whereas Bryophyllum
are paired except urinogenital duct, penis and reproduces through vegetative propagation.
.
(4) Androecium : : : Gynoecium : Carpels
(1) testes (2) Y (3) Note: No glands are same is
Ans. 
Ans. Stamen - Androecium is male whorl and
male and female reproductive system of human.
its members are called as stamen whereas
(4) uterus (5) Asexual (6) fragmentation (7) meiosis
Gynoecium is female whorl and its members are
(8) mitotic (9) embryo (10) Cyst (11) Dermal layers
called as carpels.
(12) diploid zygote (13) Androecium (14) nine
months (15) cyst (16) vegetative propagation (5) XX - chromosomes : Female : : : male
(17) regeneration (18) mucor (19) meiosis Ans. XY - chromosomes - One pair of sex chromosomes
(20) Flower (21) Androecium and gynoecium in males is XY, whereas in female it is XX.
(22) pedicel (23) carpels (24) Stigma (25) seminiferous
(6)  alyx and corolla : Accessory whorls : : Androecium
C
tubules (26) Germinal epithelium (27) Menopause
and Gynoecium : .
(28) asexual, sexual (29) mitochondria, chloroplasts
(30) bisexual (31) fertilization (32) placenta Ans. Essential whorls - Androecium and gynoecium
(33) estrogen (34)progesterone (35) In Vitro are called ‘essential whorls’ because they perform
Fertilization (IVF) (36)surrogacy (37) Monozygotic the function of reproduction, whereas calyx and
(38) conjoined twins (Siamese twins) (39) health corolla are called ‘accessory whorls’ because they
(40) corpus albicans (41) Endosperm (42) Scrotum are responsible for protection of inner whorls.
(43) Semen (44) Parturition (45) Scrotum (7) Ovule : Seed : : Ovary : .
Q.1. (A) 2. Select the odd man out: Ans. Fruits - After fertilization, ovary develops into
(1) Stigma, style, anther, ovary. fruit, whereas ovules develop into seeds.
Ans. Anther - others are female reproductive parts of a (8) Calyx : Sepals : : Corolla : .
flower whereas anther is the male part. Ans. Petals - Members of calyx are called ‘sepals’
(2) Vagina, uterus, testes, ovaries. whereas, members of corolla are called ‘petals’.
Ans. Testes - others are female reproductive organs (9) Single embryo : Monozygotic twins : : Two embryos
whereas testes are male reproductive organs. : .
(3) Bryophyllum, carrot, raddish, Spirogyra. Ans. Dizygotic twins - Monozygotic twins are formed
Ans. Spirogyra - others reproduce by vegetative from single embryo whereas, dizygotic twins are
propagation whereas Spirogyra reproduces by formed from two separate oocytes and sperms.
fragmentation. (10) Planaria : Regeneration : : Mucor : .
(4) Rete testes, urinogenital duct, oviduct, Ans. Spore formation - Planaria reproduces by
epididymis. fragmentation, whereas Mucor reproduces by
Ans. Oviduct - others are male reproductive organs spore formation.
whereas oviduct is a female reproductive organ.
(11) Root, stem, leaf : Vegetative propagation : : Flower
Q.1. (A) 3. Complete the analogy: : .
(1) Prokaryote : Bacteria : : Protist : . Ans. Sexual reproduction - Root, stem and leaf
Ans. A
 moeba - Prokaryotes like bacteria and Protists reproduces by vegetative propagation of asexual
like Amoeba perform asexual reproduction by reproduction, whereas flower reproduces by
binary fission. sexual reproduction.
(2) Paramoecium : : : Euglena : longitudinal (12) Length of epididymis : 6 meters : : Length of a sperm
binary fission : .
Ans. Transverse binary fission - Paramoecium divides Ans. 60 micrometers - Length of each epididymis is
by transverse binary fission, whereas Euglena by about 6 meters, while the length of a sperm is
longitudinal binary fission. about 60 micrometers.
46 Master Key Science and Technology Part-2 (Std. X)

Q.1. (A) 4. Match the columns: (13) Approximately 2 - 4 million oocytes are released
(1) Column ‘A’ Column ‘B’ upto the age of menopause.
(1) Amoeba (a) Fragmentation (14) When pollination involves two flowers borne on
(2) Yeast (b) Vegetative the same plant, it is called as cross-pollination.
propagation (15) Flowers with stalk are called as sessile.
(3) Bryophyllum (c) Binary fission (16) Each embryo sac consists of two haploid egg cell
(4) Mucor (d) Budding and one haploid polar nuclei.
(e) Spore formation (17) The mother is responsible for a girl child.
Ans. (1 – c); (2 – d); (3 – b); (4 – e) (18) X-chromosome is present in men and women.
(2) Column ‘A’ Column ‘B’ (19) Paramoecium divides by longitudinal binary
(1) FSH (a) Regeneration of fission.
endometrium Ans. (1) False. Absence of genetic variation is a drawback
(2) Luteinizing (b) Secretion of of asexual reproduction. (2) True (3) False. Spirogyra
hormone endometrial glands reproduces by fragmentation. (4) True (5) False.
(3) Progesterone (c) Development of Calyx and corolla are called as accessory whorls.
follicle (6) False. Members of calyx are called as sepals.
(4) Estrogen (d) Ovulation (7) False. Papaya is an unisexual flower. (8) False.
Ans. (1 – c); (2 – d); (3 – b); (4 – a) Y-chromosome is present only in men. (9) True
(10) False. The minimum age for marriage in India
(3) Column ‘A’ Column ‘B’
is 18 for girls and 21 for boys. (11) False. Sperm and
(1) 44 + XY (a) Female ovum are formed by meiosis. (12) True (13) False.
(2) 44 + XX (b) Identical twins Approximately 400 oocytes are released upto the age
(3) Monozygotic (c) Non-identical twins of menopause. (14) False. When pollination involves
twins two flowers borne on the same plant, it is called self-
(4) Dizygotic (d) Male pollination. (15) False. Flowers with stalk are called
twins pedicellate. (16) False. Each embryo sac consists
Ans. (1 – d); (2 – a); (3 – b); (4 – c) of a haploid egg cell and two haploid polar nuclei.
(17) False. The father is responsible for a girl child.
Q.1. (A) 5. State whether the following statements
(18) True (19) False. Paramoecium divides by
are true or false. Correct the false statements.
transverse binary fission.
(1) Absence of genetic variation is an advantage of
Q.1. (A) 6. Name the following:
asexual reproduction.
(2) Binary fisson is usually performed by living *(1) Hormones related with male reproductive system
organisms under favourable conditions. Ans. 
FSH (Follicle stimulating hormone), LH
(3) Spirogyra reproduces by regeneration. (Luteinizing hormone), testosterone.
(4) Diversity in living organisms occurs due to *(2) Hormones secreted by ovary of female
genetic variation. reproductive system.
(5) Calyx and corolla are called as essential whorls. Ans. Estrogen and progesterone
(6) Members of calyx are called as petals. *(3) Types of twins
(7) Papaya is a bisexual flower. Ans. Monozygotic twins and dizygotic twins.
(8) Y-chromosome is present in men and women. *(4) Any two sexual diseases.
(9) After fertilization, ovule develops into seed and Ans. Syphilis and gonorrhea
ovary into fruit.
*(5) Methods of family planning
(10) The minimum age for marriage in India is 18 for
Ans. Intra uterine device, use of condoms
girls and boys.
(6) Advanced medical techniques for reproduction
(11) Sperm and ovum are formed by mitosis.
Ans. IVF, Surrogacy, Sperm bank.
(12) Fertilization in humans is internal.
Life Processes in Living Organisms Part - 2 47

(7) Hormones that control menstrual cycle (6) When is a flower called bisexual?
Ans. 
FSH (Follicle stimulating hormone), LH Ans. A flower is called as bisexual if both essential
(Luteinizing hormone), estrogen and whorls, i.e. androecium and gynoecium are
progesterone. present in the same flower, Eg. Hibiscus.
(8) Organs of female reproductive system in human. (7) When a flower is called unisexual?
Ans. Pair of ovaries, pair of oviducts, single uterus and Ans. 
A flower is called unisexual if any one of the two
a vagina. essential whorls are present in a flower. Eg. Papaya.
(9) Organs of male reproductive system in human (8) What is pedicel?
Ans. Testes, rete testis, vas eferens, epididymis, vas Ans. The stalk present in a flower for its support is
deferens, ejaculatory duct, urinogenital duct, called as pedicel.
seminal vesicles, prostate gland, cowper’s gland. (9) What are sessile flowers?
(10) Four floral whorls. Ans. Flowers with absence of stalk are called as sessile
Ans. Calyx, corolla, androecium, gynoecium. flowers.
(11) Accessory whorls in a flower. *(10) Which hormone is released from pituitary of
Ans. Calyx and corolla mother once the fetal development is completed?
(Can you tell;Textbook Page No. 31)
(12) Essential whorls in a flower.
Ans. Oxytocin is the hormone released from pituitary
Ans. Androecium and gynoecium
of the mother, once fetal development is
Q.1. (A) 7. Answer the following in one sentence:
completed.
*(1) Which are the important life processes in living
*(11) Under the effect of that hormone, which organ
organisms? (Can you recall; Textbook Page No. 22)
of the female reproductive system starts to
Ans. Control and co-ordination, respiration, growth, contract and thereby birth process (Parturition) is
excretion, reproduction, nutrition and excretion facilitated? (Can you tell; Textbook Page No. 31)
are some of the important life processes in living
Ans. U
 terus starts to contract under the effect of
organisms.
oxytocin hormone and facilitates parturition.
*(2) Which life processes are essential for production
Q.1. (B) Choose and write the correct option:
of energy required by body?
(Can you recall; Textbook Page No. 22) (1) divides by simple binary fission.
Ans. 
Nutrition and respiration are the processes (a) Paramoecium (b) Amoeba
essential for production of energy. (c) Euglena (d) Hydra
*(3) Whether the new organism is genetically exactly (2) reproduces by longitudinal binary
similar to earlier one that has product it? fission.
(Can you tell; Textbook Page No. 22) (a) Paramoecium (b) Amoeba
Ans. O
 ffsprings are genetically similar to parents if (c) Euglena (d) Hydra
they reproduce asexually and offsprings are
(3) Hydra reproduces by .
genetically different if they reproduce sexually.
(a) binary fission (b) budding
*(4) Who determines whether the two organisms of a
(c) fragmentation (d) multiple fission
species will be exactly similar or not?
(4) Which of the following is a mode of asexual
(Can you tell; Textbook Page No. 22)
reproduction?
Ans. Method of reproduction will determine whether
(a) Multiple fission (b) Spore formation
the two organisms of species will be exactly
similar or not. (c) Budding (d) All of these

(5) What is gamete formation? (5) For binary fission, Amoeba requires
parent cells.
Ans. Formation of sperm and ovum by meiosis is
called as gamete formation. (a) three (b) two (c) one (d) zero
48 Master Key Science and Technology Part-2 (Std. X)

(6) Yeast reproduces by . (3) Reproduction

(a) budding (b) binary fission Ans. F
ormation of new organism of the same
(c) spore formation (d) multiple fission species by earlier existing organism is called as
(7) reproduces from the buds on the reproduction.
leaf margin. (4) Vegetative propogation
(a) Lotus (b) Hibiscus Ans. R
 eproduction in plants with the help of vegetative
(c) Bryophyllum (d) Papaya parts like root, stem, leaf and bud is called as
(8) is present at the tip of the style. vegetative propogation.
(a) Stigma (b) Anther (c) Ovary (d) Ovule (5) Regeneration
(9) is formed in each ovule by meiosis. Ans. A
 sexual reproduction in which body of parent
(a) Pollen grains (b) Seeds organism breaks into many fragments from
which each starts life independently.
(c) Embryo sac (d) Fruit
(6) Pollination
(10) Zygote develops at the cost of the food stored in
. Ans. T
 ransfer of pollen grains from anther to stigma
(a) endosperm (b) pollen grain of a flower is called as pollination.
(c) fruit (d) ovary (7) Germination
(11) Testes secrete the hormone Ans. T
 he process of change of a seed to a new plantlet
under favourable conditions of food moisture
(a) progesterone (b) FSH
and air is called germination.
(c) estrogen (d) testosterone
(8) Menopause
(12) At the time of birth, there are
immature oocytes in the ovary of female foetus. Ans. T
 he natural cessation of menstruation that occurs
between age 45-50 years is known as menopause.
(a) 2 - 4 hundred (b) 5 - 6 hundred
(9) Pedicellate flowers
(c) 2 - 4 million (d) 8 - 10 million
Ans. F
 lowers which have a stalk for support (pedicel)
(13) Menopause occurs at the age of
are called pedicellate flowers.
years.
(10) Sessile flowers
(a) 18 - 20 (b) 45 - 50
(c) 20 - 30 (d) 18 Ans. F
 lowers which do not have a stalk for support are
called sessile flowers.
(14) Menstrual cycle occurs at an interval of every
days. (11) Fertilization

(a) 8 - 10 (b) 15 - 20 Ans. The process of formation of a diploid zygote by

the union of haploid male and female gametes is
(c) 28 - 30 (d) 6 - 7
called as fertilization.
Ans. (1) (b) Amoeba (2) (c) Euglena (3) (b) budding (4)
(d) All of these (5) (c) one (6) (a) budding (7) (c) (12) Ovulation
Bryophyllum (8) (a) Stigma (9) (c) Embryo sac (10) Ans. B
 ursting of mature ovarian follicle under the
(a) endosperm (11) (d) testosterone (12) (c) 2 - 4 influence of hormones to release the oocyte is
million (13)(b) 45 - 50 (14) (c) 28 - 30 called ovulation.
Q.2.1. Define or explain the following: (13) Parturition
(1) Asexual reproduction Ans. T
 he process of giving birth to a new born baby is
Ans. P
 rocess of formation of new organism by an called parturition.
organism of same species without involvement (14) Twins
of gametes is called asexual reproduction. Ans. T
 wo embryos develop simultaneously in the same
(2) Sexual reproduction uterus and thus two offsprings are delivered
Ans. R
 eproduction that occurs due to fertilization of simultaneously. Such offsprings are called as
gametes is called sexual reproduction. twins.
Life Processes in Living Organisms Part - 2 49

Q.2.2. Write short notes: (4) Pollination.

(1) Multiple Fission Ans. 
Ans.  (i) Transfer of pollen grains from the anther to the
stigma is called as pollination.
(i) Asexual reproduction by multiple fission is
performed by Amoeba and other similar protists. (ii) Pollination occurs with the help of abiotic agents
(wind, water) and biotic agents (insects and
(ii) Amoeba stops the formation of pseudopodia and
animals).
thereby its movements whenever there is lack of
(iii) When pollination involves only one flower
food or any other adverse condition.
or two flowers of the same plant, it is called as
(iii) It becomes rounded and forms a protective self-pollination
covering around plasma membrane. Such
(iv) If it is involves two flowers borne on two plants
encysted Amoeba or any other protist is called as
of the same species, it is called cross-pollination.
cyst.
(5) Surrogacy
(iv) Many nuclei are formed by repeated nuclear
Ans. 
division in the cyst, followed by cytoplasmic
division and thus many amoebulae are formed. (i) Some women have problems in implantation of
embryo in uterus.
(v) They remain encysted till there are adverse
conditions. (ii) Such women can take the help of the modern
remedial technique called as surrogacy.
(vi) Cyst breaks open on arrival of favourable
conditions and many amoebulae are released. (iii) In this technique, oocyte is collected from
the ovary of the woman having problem in
(vii) This process is called Multiple fission. implantation in uterus.
(2) Fragmentation (iv) That oocyte is fertilized in test-tube with the help
Ans.  of sperms collected from her husband.
(i) This type of asexual reproduction occurs in (v) The embryo formed from such fertilization is
multicellular organisms. implanted in the uterus of some other woman
(ii) In this type of reproduction, the body of parent having normal uterus.
organism breaks up into many fragments and (vi) Such a woman, in whose uterus the embryo is
each fragment starts to live as an independent implanted is called as surrogate mother.
new organism. (6) Sperm Bank/ Semen Bank
(iii) It is seen in algae like Spirogyra and sponges like Ans. 
sycon. (i) There are various problems in sperm production
in case of many men like absence of sperms, slow
(iv) When plenty of water and nutrients are available
movement of sperms, etc.
to Spirogyra, its filaments grow up very fast and
(ii) So as to have children in case of such couples,
break up into small fragments.
new concept of sperm bank has been introduced.
(v) Each fragment starts to live independently as a This concept is similar to blood bank.
new Spirogyra fiber.
(iii) Semen ejaculated by the desired men is collected
(vi) Similarly, if the body of Sycon breaks up after their thorough physical and medical check-
accidentally into many fragments, each fragment up and stored in the sperm bank.
develops into a new Sycon.
(iv) As per the wish of the needful couple, oocyte of
(3) Regeneration woman of the concerned couple is fertilized by
Ans.  IVF technique using the semen from the sperm
(i) Wall lizard breaks up and discards some part of bank.
its tail in emergency. (v) Resultant embryo is implanted in the uterus of
(ii) Discarded part is regenerated after a period. This the same woman.
is an example of limited regeneration. (vi) Name of the semen donor is strictly kept secret as
(iii) However, under certain situation, an animal- per the law.
Planaria breaks up its body into parts and (7) Population Explosion
thereafter each part regenerates remaining part Ans. 
of the body and thus new planaria are formed. (i) Excessive growth of population within short
duration is called as population explosion.
(iv) This is called regeneration.
50 Master Key Science and Technology Part-2 (Std. X)

(ii) Due to population explosion we have to face parts like root, stem, leaf and bud is called as
problems like unemployment, decreasing per Vegetative reproduction propogation
capita income and increasing loan, stress on (ii) Vegetative propogation in potatoes is performed
natural resources etc. with the help of ‘eyes’ present on tuber whereas
(iii) There is only one solution for all such problems in Bryophyllum it is performed with help of bud
and it is population control. present on leaf margin.
(iv) Population control can be achieved by family (iii) In case of plants like sugarcane and grasses,
planning. vegetative propogation occurs with the help of
(8) Vegetative propogation buds present on leaf margin.
Ans.  (iv) Plants like carrot and radish perform vegetative
(i) Reproduction in plants with the help of vegetative propogation with the help of roots.
Q.2.3. Distinguish between:
(1) Binary fission and Multiple fission

Ans. Binary Fission Multiple Fission

(i) In this process the parent cell divides to form (i) In this process, the parent cell divides within the
two daughter cells. cyst to form many daughter cells.
(ii) It occurs under favourable conditions. (ii) It occurs under adverse conditions.
(iii) There is no cyst formation. (iii) The organism forms a protective covering around
itself called as cyst.
(iv) Nucleus divides into two halves (iv) Nucleus divides into many nuclei.
(2) Human Male and female reproductive system
Ans. Human Male reproductive system Human Female reproductive system
(i) Testes are the essential organs. (i) Ovaries are the essential organs.
(ii) Testes secrete testosterone (ii) Ovaries produce estrogen and progesterone.
(iii) Millions of sperms are produced in one time. (ii) Single oocyte is produced per month.
(iv) Male gametes are sperms. (iv) Female gametes are oocytes.

Q.2.4. Answer the following: *(3) What would have happened if the male and
*(1) Which are the main types of cell division? What are female gametes had been diploid? (Let’s think;
the differences? (Can you recall; Textbook Page No. 22) Textbook Page No. 26)
Ans.  Ans. 
(i) The two main types of cell division are ‘mitosis’ (i) If the gametes were diploid, the zygote would
and ‘meiosis’. get 46 chromosomes from the father and 46
(ii) Mitosis occurs in somatic cells and stem cells of chromosomes from the mother, that would add
the body, whereas meiosis occurs in germ cells. up to 92.
(iii) In mitosis, the chromosome number remains the (ii) This would lead to diseases or complications in
same and two daughter cells are obtained from the offspring.
one cell. *(4) What would have happened if any of the cells
(iv) In meiosis, chromosome number is reduced to in nature had not been divided by meiosis?
half and four daughter cells are obtained from (Let’s think; Textbook Page No. 26)
one cell. Ans.
*(2) What is the role of chromosomes in cell division? (i) Meiosis is necessary for sexual reproduction and
(Can you recall; Textbook Page No. 22) for increasing genetic diversity.
Ans.  As the genetic material passes from parents (ii) If meiosis were to disappear tomorrow, all
to child, the chromosomes are responsible sexually reproducing organisms would stop
for containing the instructions that make the having offsprings.
offspring unique while still carrying traits from (iii) This would lead to the extinction of the majority
their parents. of the world’s diploid species.
Life Processes in Living Organisms Part - 2 51

*(5) Why has the Government of India enacted the its tail in emergency. (ii) This discarded part is
law to fix the minimum age of marriage as 18 in regenerated after a period. (iii) This is limited
girls and 21 in boys? (Can you recall; Textbook Page regeneration.
No. 28) (12) How does fertilization take place in humans?
Ans. Ans. 
(i) The Government of India has enacted the law to (i) Formation of zygote by union of sperm and ovum
fix the minimum age of marriage as 18 in girls is called fertilization.
and 21 in boys because at this age girls and boys (ii) Fertilization is internal in humans.
become adults. (iii) Semen is ejaculated in vagina during copulation.
(ii) They have developed the secondary sexual (iv) Few million sperms start their journey by the
characteristics, and they are physically and route of vagina-uterus-oviduct.
mentally ready to reproduce. (v) One of those million sperms fertilize the only
*(6) What do we mean by maintenance of species? ovum present in the oviduct.
(Can you tell; Textbook Page No. 22) Q.2.5. Give scientific reasons:
Ans. (i) The process of reproduction helps to increase (1) New organism has exact genetic similarity
the number of organisms of a species by which with the reproducing organism in asexual
the species can prevent itself from being extinct. reproduction.
(ii) This is called as maintenance of species. Ans.
(i) Process of formation of new organism by an
*(7) What is the relationship between the cell
division and formation of new organism of the organism of same species without involvement
same species by earlier existing organism? (Can of gametes is called as asexual reproduction.
you tell; Textbook Page No. 22) (ii) As this reproduction does not involve union of
two different gametes, the new organism has
Ans.
exact genetic similarity with the reproducing
(i) In case of asexual reproduction, the parent cell organism.
divides to form two similar daughter cells. This (2) Sperm needs large amount of energy.
occurs by the type of cell division called mitosis. Ans.
(ii) In case of sexual reproduction, gametes are (i) Length of each epididymis is about 6 meters
formed by the type of cell division called meiosis. whereas length of a sperm is about 60
These gametes fuse to form a new organism micrometers.
*(8) Which hormones are responsible for changes in (ii) Such a small sperm has to cross the distance of
human body during onset of sexual maturity? approximately 6.5 meters while passing out of
(Can you recall; Textbook Page No. 28) male reproductive system to the oviduct .
Ans. The hormones responsible for changes in (iii) Hence, sperms need large amount of energy.
human body during onset of sexual maturity (3) There is need of rest alongwith special personal
are testosterone in males and estrogen and hygiene during menstrual cycle.
progesterone in females. Ans.
*(9) Does the parent cell exist after asexual (i) Menstrual cycle is a natural process and women
reproduction fission? (Use your brain power; experience pains during this phase.
Textbook Page No. 24) (ii) Severe weakness is felt due to heavy bleeding.
(iii) There is higher possibility of infection too during
Ans.
this phase.
(i) In asexual reproduction - Fission, the mother cell
(iv) Due to all such reasons, there is need of rest along
divides into daughter cells as each daughter cell
with special personal hygiene.
begins its life like a new individual.
Q.3.1. Explain the following:
(ii) The parent cell thus do not exist after asexual
reproduction - fission. *(1) Explain the concept of IVF.
Ans.
*(10) Which different hormones control the functions (i) In the IVF technique, fertilization is brought
of human reproductive system through about in the test tube and the embryo formed is
chemical co-ordination? (Can you recall; Textbook
implanted in uterus of a woman at appropriate
Page No. 28)
time.
Ans. FSH (Follicle stimulating hormone) LH (ii) IVF technique is used for having the child in case
(Luteinizing hormone) male hormone - of those childless couples who have problems
testosterone act female hormone - estrogen and like less sperm count, obstacles in oviduct etc.
progesterone are the different hormones that *(2) Which precautions will you follow to maintain
control the functions of human reproductive the reproductive health?
system through chemical co-ordination. Ans.
(11) Give an example of limited regeneration. (i) A person’s state of being physical, mental and
Ans. (i) Lizard breaks up and discards some part of social strength is called as health.
52 Master Key Science and Technology Part-2 (Std. X)

(ii) Bleeding occurs during menstrual cycle. Due *(2) Human female reproductive system
to this, private organs need to be cleaned from
Oviduct
time to time otherwise problem regarding
reproduction health may arise.
(iii) It is essential to maintain the cleanliness of
genitals of both males and females.
(iv) Also, one should avoid unsafe sexual contact.
Q.3.2. Draw a neat and labelled diagrams for the
following. Ovary
*(1) Human male reproductive system
Uterus
Urinary bladder

Vagina

Fig. 3.2. Human female reproductive system

Seminal
vesicle *(3) Flower with its sexual reproductive organs
Prostate
Stigma Gynoecium
gland Ejaculatory Corolla (Carpel)
Style
Vas deferens (Petals)
duct
Cowper’s
gland
Ovary
Urino genital
duct
Epididymis Anther Androecium
Staman

Filament
Scrotum
Testes
Calyx
(Sepals)
Penis Pedicel

Fig. 3.1. Human male reproductive system Fig. 3.3 Parts of flower
*(4) Menstrual cycle

Hypothalamus
GnRH
Changes in the Pituitary gland
ovary during FSH
menstruation LH
Corpus Corpus
luteum albicans
Fully grown follicle

Progesterone and estrogen

Estrogen Beginning of
new
Changes in the menstruation
uterus during
menstruation
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 22 23 24 25 26 27 28 1 2
Period of Period of
Menstruation regeneration of Ovulation Period of secretions of
endometrium period glands in endometrium

Fig. 3.4 Menstrual cycle

Life Processes in Living Organisms Part - 2 53

*Q.3.3.Observe the pictures and tell the life process which you identified. (Observe; Textbook Page No. 22)

(a) (b) (c) (d)

Fig. 3.5 Some life processes
Ans. The life process observed is reproduction.
(iv) New individual (iv) New individual
*Q.3.4. Complete the paragraph with the help of formed by formed by
words given in the bracket this method this method
(Luteinizing hormone, endometrium of uterus, follicle is genetically is genetically
stimulating hormone, estrogen, progesterone, corpus identical to the different from
luteum) parent. parents.
Growth of follicles present in the ovary occurs
(v) Asexual (v) Sexual
under the effect of . This follicle
reproduction reproduction
secretes estrogen. grows/
occurs in different occurs by two
regenerates under the effect of estrogen. Under
individuals by main processes -
the effect of fully grown up follicle
various methods gamete formation
bursts, ovulation occurs and is
like binary and fertilization.
formed from remaining part of follicle. It secretes
fission, multiple
and . Under the effect
fission, budding,
of these hormones, glands of are
fragmentation,
activated and it becomes ready for implantation.
regeneration,
Ans. (1) follicle stimulating hormone (2) endometrium of
vegetation
uterus (3) luteinizing hormone (4) corpus luteum
propagation,
(5) progesterone (6) estrogen (7) endometrium
spore production
Q.3.5. Complete the the following chart:
etc.
*(1)
Ans. Asexual reproduction Sexual reproduction (2)
(i) Reproduction (i) Reproduction Ans. Method of Asexual Organisms / Example
that occurs with that occurs due reproduction
the help of to formation
somatic cells is of gametes is (i) Binary fission (i) Amoeba,
called as asexual called as sexual Paramoicium
reproduction. reproduction.
(ii) Multiple fission (ii) Amoeba
(ii) Male and female (ii) Male and
parents are female parent (iii) Budding (iii) Yeast cells, Hydra
not necessary are necessary
(iv) Fragmentation (iv) Spirogyra
for asexual for sexual
reproduction. reproduction (v) Regeneration (v) Planaria
(iii) This reproduction (iii) This reproduction (vi) Spore formation (vi) Mucor
occurs with the involves meiosis
help of mitosis during gamate
only. formation.
54 Master Key Science and Technology Part-2 (Std. X)

Q.3.6. Observe the figure and answer the following (b) Is the flower unisexual or bisexual? Why?
questions: Ans. The flower is bisexual because both the
(1) male (Androecium) and female (Gynoecium
reproductive organs are present in it.
(c) Where are the male and the female gametes
present?
Ans. The male gametes are in the anther region inside
the pollen grains whereas the female gametes are
in the ovary called ovules.
(d) What is a flower without part (C) called?
Ans. It is called a sessile flower.

(3) For diagram refer Fig. 3.4

(a) Name the hormones involved in menstrual cycle.
Ans. hormones Estrogen and Progesterone are
Fig. 3.6. Vegetative propogation
involved in menstrual cycle.
(a) Which method of reproduction is shown in the
(b) What is the meaning of ovulation?
diagram?
Ans. Vegetative propagation Ans. Ovulation is the release of oocyte on bursting
(b) Is it an asexual or sexual method of reproduction? of mature ovarian follice under the influence of
Why? hormones.
Ans. It is an asexual method of reproduction because (c) Under what condition will corpus luteum get
only the root, stem and leaf are participating in transformed into corpus albicans?
the reproduction. Ans. If oocyte is not fertilized, corpus luteum loses its
(c) Give examples of plants undergoing this method function and becomes a degenerate body called
of reproduction.
as corpus albicans.
Ans. Raddish and carrot perform vegetative
Q.4. Answer in detail.
propogation through roots and sugarcane and
grasses through buds. *(1) What is Menstrual cycle? Describe it in brief.
(2) Ans. [For diagram, refer fig. 3.4]
B (i) Female reproductive system undergoes some
changes at puberty and those changes repeat at
the interval of every 28 - 30 days. These repetitive
changes are called as menstrual cycle.
(ii) Menstrual cycle in a natural process controlled
by four hormones. Follicle stimulating hormone
(FSH), Luteinizing hormone (LH), estrogen and
progesterone.
A
(iii) One of the several follicles in the ovary starts
to develop along with the oocyte present in it,
C under the effect of follicle stimulating hormone.
This developing follicle secrets oestrogen.
(a) Label the parts (A), (B) and (C) (iv) Endometrium of the uterus starts to develop or
Ans. (A) It is the Androecium of Anther and filament, regenerate under the effect of estrogen.
(B) It is the Gynoecium with the stigma, style and (v) Meanwhile developing follicle completes its
ovary (C) It is the pedicel development.
Life Processes in Living Organisms Part - 2 55

(vi) It bursts under the effect of lutenizing hormone (iv) Thus, gender of child is determined by the male
and oocyte is released. This is called as ovulation. partner of the couple.
(vii) Remaining tissues of the burst follicle forms the (v) So, the above statement is true.
corpus luteum. Corpus luteum starts to secrete
progesterone. Sperms Oocytes

(viii) Endometrial glands secrete their secretion under (22 + X) (22 + Y) (22 + X) (22 + X)
the effect of progesterone. Such endometrium is
ready for implantation of embryo.
Girl (44 + XX) Boy (44 + XY)
(ix) If oocyte is not fertilized within 24 hours, corpus
luteum becomes inactive and transforms into
*(4) Explain asexual reproduction in plants.
corpus albicans.
Ans.
(x) Endometrium starts to degenerate in absence of (i) Reproduction in plants with the help of vegetative
estrogen and progesterone. parts like root, stem, leaf and bud is called as
(xi) Tissues of degenerating endometrium and vegetative reproduction.
unfertilized ovum are discarded out through (ii) Vegetative propagation in potatoes is performed
vagina, accompanied by bleeding. with the help of eyes present on tuber whereas
(xii) Bleeding continues approximately for 5 days. in Bryophyllum, it is performed with the help of
This is called mensturation. buds present on leaf margin.
*(2) In case of sexual reproduction, newborn shows (iii) In case of plants like sugarcane and grasses,
similarities about characters. Explain this vegetative propagation occurs with the help of
statement with suitable example. buds present on nodes.
Ans.  (iv) Plants like carrot and raddish perform vegetative
(i) Two parents i.e. male and female are involved in propagation with the help of roots.
sexual type of reproduction. (v) Plants like Spirogyra reproduces asexually by
(ii) In sexual reproduction fusion of male gamete fragmentation.
and female gamete occurs. (vi) When there is plenty of water and nutrients
(iii) Due to this, new individuals always has the available to Spirogyra, its filaments grow up very
recombined genes of both the parents. fast and break up into many small fragments.
(iv) Hence, the new individual show similarities Each fragment starts to live independently as a
with the parents for some characters and also has new spirogyra fibre.
characters different from both parents. (5) Explain budding in Yeast.
*(3) Gender of child is determined by the male Ans.
partner of couple. Explain with reasons whether
Daughter
this statement is true or false. yeast
Bulge New Bud
Ans.
Parent yeast cell
(i) During zygote formation, man contributes either
X or Y chromosome to the next generation.
(ii) But, female transfers only X-chromosome to the
next generation.
(iii) At the time of fertilization, if X-chromosome Fig. 3.7. Budding
comes from male, the child will be a girl. And
(i) Budding is a method of asexual reproduction in a
if Y-chromosome comes from the male then the unicellular fungus-yeast.
child will be a boy.
(ii) Yeast cell produces two daughter nuclei by
56 Master Key Science and Technology Part-2 (Std. X)

mitotic division. This yeast cell is called as parent (8) Name two common sexual diseases. What are
cell. their symptoms?
(iii) A small bulge appears on the surface of parent Ans.
cell which is the bud. (i) Two common sexual diseases are syphilis and
(iv) One of the two daughter nuclei enters this bud. gonorrhea.

(v) After sufficient growth, bud separates from the (ii) Both are caused by bacteria.
parent cell and starts to live independently, as a (iii) Symptoms of syphilis are chancre (patches) on
daughter yeast cell. various parts of the body including genitals, rash,
(6) Explain the process of spore formation. fever, inflammation of joints, alopecia, etc.
Ans.  (iv) Symptoms of gonorrhea are painful and burning
Sporangium sensation during urination, oozing of pus through
penis and vagina, inflammation of urinary tract,
Greenish Layer Spores anus, throat, eyes, etc.
(9) Describe the human male reproductive system
with the help of a neat labelled diagram.
Hyphae Ans. (For diagram, refer Fig. 3.1)
(i) Human male reproductive system consists of
testes, various ducts and glands.
Rhizoid (ii) Testes are present in the scrotum, outside the
Piece of bread abdominal cavity.
Fig. 3.8. Spore formation (iii) Testes contain numerous seminiferous tubules
Germinal epithelium present in the tubules
(i) Spore formation is a method of asexual
divide by meiosis to produce sperms.
reproduction in fungi like mucor.
(iv) Those sperms are sent forward through various
(ii) Mucor has filamentous body and sporangia
which produce spores. tubules. Sequence of those tubules is as rete testes,
vas eferens, epididymis, vas deferens, ejaculatory
(iii) Once the spores are formes, sporangia burst and
duct and urinogenital duct.
spores are released.
(iv) Spores germinate in moist and warm place and (v) As the sperms are pushed forward from one duct
new fungal colony is formed. to next, they become mature and able to fertilize
the ovum.
(7) Describe the process of development and birth
in humans. (vi) Seminal vesicles secrete their secretion in
Ans.  ejaculatory ducts whereas prostate glands and
(i) The zygote formed after fertilization in the Cowper’s glands secrete their secretions in
oviduct, undergoes repeated mitotic divisions urinogenital duct.
and embryo is formed. (vii) Semen is formed of sperms and secretions of all
(ii) Meanwhile, it is pushed towards the uterus. these glands.
(iii) Once it reaches the uterus, it is implanted and (viii) Semen is ejaculated out through the penis.
further development occurs after implantation. (ix) All the organs of male reproductive system are
(iv) An organ called as placenta is formed for supply paired except urethra prostate grands, penis and
of food material during the growth of the embryo scrotum.
in the uterus.
Note : In textbook urogenital duct is given instead of
(v) Embryonic development is completed approximately urethra. Urogenital duct is a term which is used to
within nine months after fertilization following refer something with urinary and genital origin.
which birth takes place.
Life Processes in Living Organisms Part - 2 57

(10) Describe the human female reproductive (ix) Such twins are genetically different and be same
system with the help of a neat labelled diagram. or different by gender.
Ans. (For diagram, refer Fig. 3.2) *(12) Modern techniques like surrogate mother,
(i) All organs of female reproductive system are in sperm bank and IVF technique will help the
abdominal cavity. human beings. Justify this statement.
(ii) It includes a pair of ovaries, a pair of oviduct, Ans.
single uterus and a vagina.
(i) Modern techniques like surrogacy, IVF and sperm
(iii) A pair of Bartholin’s gland is also present. bank have been boon to the childless couples
(iv) Generally every month an ovum is released in
(ii) In IVF technique, fertilization is brought about
abdominal cavity alternately from each ovary.
in a test-tube and the embryo thus, formed is
(v) Free-end of the oviduct is funnel like. An opening implanted in the uterus of the women.
is present at the centre of it.
(iii) Surrogacy is a boon to women who face issues
(vi) Oocyte enters the oviduct through that opening.
with their uterus. In this technique, oocyte
(vii) Cilia are present on inner surface of oviduct. is collected from the mother and sperms are
These cilia push the oocyte towards the uterus. collected from father.
(11) What are twins? What are their types? (iv) They are fertilized in the test tube and the embryo
Ans.
is implanted in the uterus of some other woman
(i) Two embryos develop simultaneously in the same
having normal uterus. This process is called
uterus and thus two offsprings are delivered
surrogacy and the woman bearing the child is
simultaneously. Such offsprings are called as twins.
called as surrogate mother.
(ii) There are two main types of twins-monozygotic
(v) Sperm Bank or semen bank has been a boon
twins and dizygotic twins.
for males who face issues with sperm count or
(iii) Monozygotic twins are formed from single motility.
embryo. During early period of embryonic
(vi) Sperm banks are similar to blood bank where
development (within 8 days of zygote formation),
semen from physically and medically fit
cells of that embryo divide into two groups.
individuals are collected and stored.
(iv) Those two groups develop as two separate
(vii) Thus modern techniques like IVF, surrogacy and
embryos and thus monozygotic twins are formed.
sperm bank help human beings.
(v) Such twins are genetically exactly similar to each
*(13) Explain sexual reproduction in plants.
other. So they are similar in appearance and their
gender is also same i.e., both will be either boys Ans. (For diagram of flower, refer Fig. 3.3)
or girls. Pollen
Stigma grain Egg cell
(vi) In case of monozygotic twins, if the embryonic Male
Pollen Synergids Polar
Style tube Nucleus
cells are divided into two groups 8 days after Gametes
Embryo
fertilization, there is high possibility of formation Sac
Ovary Ovules
of conjoined twins (Siamese twins). Such twins are
Antipodals
born with some parts of the body joined to each Male
Gametes
other. Some organs are common in such twins.
Fig. 3.9 - Double Fertilization in angiosperms
(vii) Occasionally, two oocytes are released from the
ovary of the women and both are fertilized by (i) A flower is the site of sexual reproduction in
two separate sperms and two zygotes are formed. plants.
(viii) Two embryos are formed from those two zygotes (ii) It consists of four floral whorls calyx, corolla
and both are separately implanted in the uterus androceium and gynoecium.
and thus dizygotic twins are delivered after (iii) Androecium and gynoecium are called as
complete development. essential whorls.
58 Master Key Science and Technology Part-2 (Std. X)

(iv) Calyx and corolla are called as accessory whorls. Daughter Amoeba
(v) Androecium is male whorl and its members Parent Amoeba

are called stamens, will be gynoecium is female

whorl and its members are called as carpels.
(vi) Ovary present at the basal end of carpel contains
one or many ovules. A hollow style comes up
from the ovary.
(vii) Embryo sac is formed in each ovule by meiosis
and each embryo sac consists of a haploid egg
Fig. 3.10 - Binary fission
cell and two haploid polar nuclei.
(b) Multiple fission:
(viii) Pollen grains are transferred from anther to the
stigma. This is called as pollination. (i) Asexual reproduction by multiple fission is
performed by Amoeba.
(ix) When pollination occurs a long pollen tube
(ii) Amoeba stops the formation of pseudopodia
carrying two male gametes is formed.
whenever there is lack of food.
(x) Pollen tube reaches the embryo sac via style.
(iii) It becomes rounded and forms protective
(xi) Pollen tube bursts and two male gametes are
covering around plasma membrane. Such
released in embryo sac. One male gamete unites encysted Amoeba is called as cyst.
with egg cell to form zygote. This process is called
(iv) Many nuclei are formed by repeated nuclear
fertilization.
division in the cyst.
(xii) The second male gamete unites with two polar
(v) It is followed by cytoplasmic division and thus
nuclei and endosperm is formed. This is called
many amoebulae are formed.
double fertilization.
(vi) They remain encysted till there are adverse
(xiii) After fertilization ovule develops into seed and conditions. Cyst breaks open on arrival of
ovary into fruit. favourable conditions and many amoebulae are
(xiv) Seeds fall upon the ground when fruits break up released.
and they germinate in the soil under favourable Division of nucleus Daughter Amoebae
Parent Amoeba and cytoplasm
conditions.
(xv) Zygote develops at the cost of food stored in
endosperm of seed and thus a new plantlet is
formed. This is called as seed germination.
*(14) 
Explain with examples types of asexual Fig. 3.11 - Multiple fission
reproduction in unicellular organisms.
(c) Budding:
Ans.
(i) Sexual reproduction occurs by budding in yeast
(i) 
 Process of formation of new organism by an
cells.
organism of same species without involvement
(ii) Yeast cells produces two daughter nuclei by
of gametes is called as asexual reproduction.
mitotic division.
(ii) Types of asexual reproduction in unicellular
organisms: (iii) A small bulge appears on the surface of parent
cell. This is called as bud.
(a) Binary fission:
(iv) One of the two daughter nuclei enters this bud.
(i) In this process, the parent cell divides to form
two similar daughter cells. (v) After sufficient growth, bud separates from the
parent cell and starts to live independently as a
(ii) Binary fission occurs either by mitosis or amitosis.
daughter yeast cell.
e.g. Prokaryotes (bacteria), Protists (Amoeba).
Life Processes in Living Organisms Part - 2 59

(15) Explain budding in Hydra. (i) In case of Hydra, under favourable condition, at
Ans. specific part of its body, an outgrowth is formed
by repeated divisions of regenerative cells of
body wall. This outgrowth is called as bud.
(ii) Bud grows up progressively and finally forms a
small Hydra.
(iii) Dermal layers and digestive cavity of the budding
Hydra are in continuity with those of parent hydra.
(iv) Parent Hydra supplies nutrition to the budding
Bud Hydra.
Hydra

(v) Budding Hydra separates from parent Hydra and

Nascent Hydra starts to lead an independent life when it grows
up and becomes able to lead an independent life.

Fig. 3.12 - Budding

vvv

ASSIGNMENT - 3
Time : 1 hour Marks : 20

Q.1.(A) Answer the following. (3)

(1) Fill in the blanks.
Implantation of embryo occurs in .................. .
(2) Give name of: Types of twins.
(3) Select odd man out: Stigma, style, anther, ovary.
Q.1. (B) Choose and write the correct option. (2)
(1) Yeast reproduces by .
(a) budding (b) binary fission (c) spore formation (d) multiple fission
(2) Testes secretes the hormone .
(a) progesteron (b) FSH (c) estrogen (d) testosterone

Q.2. Answer the following (Any 2) (4)

(1) What is regeneration? Give an example of limited regeneration.
(2) Complete the following table
Female Reproductive System Hormone function

Hormone Functions

(i) _____________________ (i) Endometrium develops or regenerates.

(ii) _____________________ (ii) Follicles in the ovary develop.

60 Master Key Science and Technology Part-2 (Std. X)

(iii) _____________________ (iii) Endometrial glands secrete their secretions.

(iv) _____________________ (iv) Ovulation where oocyte is released.

(3) Write short note on : IVF.

Q.3. Answer the following (Any 2) (6)

(1) Give 3 points of differentiation between Asexual and Sexual methods of reproduction.
(2) Complete the given figure and explain the method of reproduction.

(3) A lady in a village was blamed to deliver a baby girl for the third time and was ill-treated by her
family. Do you think that the blame was right? Explain with reason.
Q.4.Answer in detail (Any 1) (5)
(1) Observe the figure and answer the following questions.

[2]

[C] [A] [D]

(i) Label (A) to (D)

(ii) What process is shown in the diagram?
(iii) Explain the process
(2) Draw a labelled diagram of human male reproductive system and explain in detail.
vvv
4 Environmental Management
CONCEPT MAP

Natural
types
Environment
formed by
Artificial

Biotic factors Abiotic factors

e.g. Plants, animals, e.g. Soil, temperature,
microbes, fungi light, pH, etc.

Study of interactions
of these factors
Ecology

Forest Conservation
Act, 1980

Laws for Environment Protection

environmental Act, 1986
conservation Clause 49 A
Wild Life Protection
Clause 49 B
Act, 1972

Clause 49 C

Points to Remember:
• The Ecosystem is formed by the biotic and abiotic factors and their interactions with each other.
• Biotic factors: Plants, animals, microbes.
• Abiotic factors: Air, water, soil, etc.
• Physical, Chemical and Biological factors affecting living organisms in any possible way are collectively
called as ‘Environment’. Environment is the condition in surrounding.
• There are two main types of environment. One is natural environment and the other is artificial
environment.
• The science that deals with the study of interactions between biotic and abiotic factors of the environment
is called as ‘Ecology’. Basic functional unit used to study the ecology is called ecosystem.
• A small pond is example of an ecosystem, and the Earth is the largest ecosystem.
• The environmental balance is maintained through continuous operation of various natural cycles like
water cycle, carbon cycle, gaseous cycles like nitrogen cycle, oxygen cycle, etc.

(61)
62 Master Key Science and Technology Part - 2 (Std. X)

• Environmental balance is also maintained due to various food chains of ecosystem.

• Environmental conservation has become the need of hour for mankind.
• Today, all developed, developing and underdeveloped countries have accepted the responsibility of
environmental protection.
• Unnecessary and unacceptable change in the surrounding environment due to natural events or human
activities is called as environmental pollution.
• Pollution is of various types namely, air pollution, water pollution, sound pollution, soil pollution,
thermal pollution, etc.
• Ultimate adverse effect of all these pollutions is on the existence of all the living organisms and therefore,
environmental conservation has become the need of the hour.
• Various reasons like population explosion, rapid industrialization and indiscriminate use of natural
resources, deforestation and unplanned urbanization are responsible for environmental pollution.
• Radioactive pollution can occur due to natural and artificial reasons. UV and IR radiations are natural
radiations, whereas X-rays and radiation from atomic energy plants are artificial radiations.
• Chernobyl, Windscale and Three Miles Island mishaps are the major mishaps of the world.
• Environmental conservation is our social responsibility.
• To create awareness about the conservation of environment, values like positive attitude and affection
towards environment, knowledge about it, should be inculcated among children through education.
• In 1972, United Nations Environment Program (UNEP) has been established in a conference arranged on
human and environment in which environmental problems were discussed.
• In India, a separate environmental department has been established after thorough discussion on
environmental problems.
• Ministry of Environment and Forests is involved in planning, inducting and increasing awareness about
environment and forests through various programs since 1985.
• Since existence of the human race, there is interrelationship between environment and human. Human
beings established dominance over the nature. They utilized all the natural resources as much as possible.
• Human has to play a crucial role in maintaining the environmental balance.
• Laws enacted about environmental conservation are: (i) Forest Conservation Act, 1980. (ii) Environmental
Conservation Act, 1986.
• Biodiversity is the richness of living organisms in nature due to presence of varieties of organisms,
ecosystems and genetic variations within a species.
• Biodiversity occurs at three different levels, viz. Genetic Diversity, Species Diversity and Ecosystem
Diversity.
• There should be positive attitude of human beings towards the environment for welfare of entire living
world.
• A person can perform a role of either a conservator, organizer, guide or a plant-friend etc.
• Biodiversity can be conserved by many ways. Many people in the society are voluntarily coming together
to perform this noble work of conservation of biodiversity.
• The forest conserved in the name of God and considered to be sacred is called ‘sacred grove’.
• Sacred groves are in fact ‘Sanctuaries’ conserved by the society and not by the government forest
department.
• Thirty four highly sensitive biodiversity spots are reported all over the world. At present, 86% of the
sensitive areas are already destroyed.
• As far as India is concerned, out of 135 species of animals, 85 species are found in the jungles of eastern
region.
Environmental Management 63

• The threatened species can be classified as endangered species, rare species, vulnerable species and
indeterminate species.
• International Union for Conservation of Nature (IUCN) prepares the ‘Red List’ that contains the
names of the endangered species from different countries. Pink pages of this book contain the names of
endangered species, while green pages contain the names of previously endangered but presently safe
species.

(18) ............. of the Assam is under threat due to dams

MASTER KEY QUESTION SET - 4 and indiscriminate use of water.
(19) ............. sanctuary of West Bengal is reserved for
Q.1. (A) 1. Fill in the blanks and rewrite the
tigers.
statements:
(20) Giant squirrel is an example of .............speices.
(1) The interactions between biotic and abiotic
(21) Out of the total plant species in the entire world
factors is called ............. .
50,000 are ............. .
(2) The science that deals with the study of
Ans. (1) Ecosystem (2) Ecology (3) Contamination
interactions between biotic and abiotic factors of
(4) cancerous ulcerations (5) Jivasya (6) radioactive
the environment is called ............. .
(7) Sacred grove (8) insecticides, pesticides (9)
(3) Generally, ............. of any material is called its Biodiversity (10) 13000 (11) Green peace (12)
pollution. Tiger and Rhino (13) 22nd May (14) Genetic
(4) Higher radiation of X-rays can cause ............. . diversity (15) National green (16) Jadav Molai
(5) Jivo ............. Jivanam. Payeng (17) Asiatic lion and Wild bison
(18) Manas Sanctuary (19) Sunderban Sanctuary.
(6) In human beings, sudden genetic changes are
(20) Intermediate (21) Endemic.
brought about by ............. pollution.
Q.1. (A) 2. Find the odd one out:
(7) The forest conserved in the name of God is called
(1) Air, water, animals, minerals.
............ .
Ans. Animals - others are abiotic factors
(8) ............. and ............. used in agriculture, pollutes
(2) Proteins, carbohydrates, fats, water.
water.
Ans. Water - others are organic compounds
(9) The richness of living organisms in nature due
(3) Deer, tiger, frog, lion.
to presence of variety of organisms, ecosystems
Ans. Deer - others are carnivores
and genetic variations within a species is called
............. . (4) Water cycle, nitrogen cycle, oxygen cycle, carbon
cycle.
(10) More than ......... sacred groves have been reported
Ans. Water cycle - others are gaseous cycles
in India.
(5) Adverse effects of vision, genetic change,
(11) The World’s largest organization engaged in
cancerous ulceration, tuberculosis.
environmental activities is ............. .
Ans. Tuberculosis - others are effects of radiation
(12) Habitats of ............. and ............. are under threat
(6) CO2, SO3 , O3, ketone.
in Assam in the Manas Sanctuary.
Ans. CO2 - others are secondary pollutants
(13) The World Biodiversity Day is on ............. .
(7) Deer, elephant, zebra, wolf.
(14) The occurrence of diversity among the organisms
Ans. Wolf - others are herbivores
of the same species is called ............. .
(8) CO2 , dust, ash, asbestos.
(15) ............. tribunal has been established in 2010 for
Ans. CO2 - others are solid components of air pollution
effective implementation of environment related
(9) IPCC, IUCN, BNHS, UNEP.
laws.
Ans. BNHS - others are international organisations
(16) ............. was responsible for creating forest cover
in Kokilamukh jungle of Assam. (10) Asiatic cheetah, himalayan wolf, giant squirrel,
pink headed duck.
(17) In the western ghats, habitats of ............. and
Ans. Giant squirrel - others are extinct birds and
............. of this region have been under threat.
animals
64 Master Key Science and Technology Part - 2 (Std. X)

Q.1. (A) 3. Complete the analogy:

(3) Column ‘A’ Column ‘B’
(1) Manas Sanctuary : Rhino : : Sunderban Sanctuary
(1) Herbivore (a) Man
:
Ans. Tiger (2) O
 mnivore (b) Tiger
(2) Red panda : Rare species : : Lion tailed monkey : (3) Carnivore (c) Frog
(4) Insectivore (d) Deer
Ans. Endangered species
(3) Rare species : Musk deer : : Indeterminate species Ans. (1 - d); (2 - a); (3 - b); (4 - c)
:
(4) Column ‘A’ Column ‘B’
Ans. Giant squirrel (shekhru)
(1) Producers (a) Bacteria
(4) Endangered species : Lion tailed monkey : :
Vulnerable species : (2) C
 onsumers (b) Green plants
Ans. Lion (3) Decomposers (c) Herbivores
(5) Clause 49 B : Use of articles with animal parts Ans. (1 - b); (2 - c); (3 - a)
banned : : Clause 49 C :
(5) Column ‘A’ Column ‘B’
Ans. Disclosure of the stock of artifacts made from
rare wild animals is compulsory (1) Primary consumers (a) Omnivore
(6) Sound pollution Rule : 2000 : : E-waste Rule : (2) Top level consumers (b) Autotrophs
Ans. 2011 (3) Secondary consumers (c) Herbivore
(7) 1980 : Forest Conservation Act : : 1986 : (4) Producers (d) Carnivore
Ans. Environmental Conservation Act. Ans. (1 - c); (2 - a); (3 - d); (4 - b)
(8) IUCN : International Union for Conservation of
(6) Column ‘A’ Column ‘B’
Nature : : IPCC :
(1) 1998 (a) Environmental
Ans. Intergovernmental Panel on Climate Change
Conservation Act
(9) IPCC : Geneva : : IUCN :
(2) 1 980 (b) E-waste rule
Ans. Switzerland
(3) 2011 (c) Forest Conservation Act
(10) Names of endangered species : Pink pages : :
(4) 1986 (d) Biomedical Waste Rule
Names of presently safe species :
Ans. Green pages. Ans. (1 - d); (2 - c); (3 - b); (4 - a)
Q.1. (A) 4. Match the columns: (7) Column ‘A’ Column ‘B’
(1) Column ‘A’ Column ‘B’ (1) Red panda (a) Vulnerable species
(1) Endangered species (a) Musk deer (2) S
 hekhru (b) Rare species
(2) Rare species (b) Gir Lion (3) Lion-tailed monkey (c) Indeterminate species
(3) Vulnerable species (c) Lion-tailed monkey
(d) Endangered species
(4) Indeterminate species (d) Giant squirrel
Ans. (1 - b); (2 - c); (3 - d)
Ans. (1 - c); (2 - a); (3 - b); (4 - d)
(8) Column ‘A’ Column ‘B’
(2) Column ‘A’ Column ‘B’
(1) Clause 49 B (a) Ban on trading of rare (1) WWF (a) United Nations
animals Environment Program
(2) Clause 49 C (b) Ban on the articles made (2) I UCN (b) World Wildlife fund
from skin or organs of (3) UNEP (c) Intergovernmental
wild animals Panel on Climate Change
(3) Clause 49 A (c) Disclosure of the stock
of artifacts made from (4) IPCC (d) International Union for
rare wild animals. Conservation of Nature
Ans. (1 - b); (2 - c); (3 - a) Ans. (1 - b); (2 - d); (3 - a); (4 - c)
Environmental Management 65

Q.1. (A) 5. State whether the following statements (3) Tiger, Rabbit, Wolf, Grass
are true or false. Correct the false statement: Ans. Grass Rabbit Wolf Tiger
(1) Wild animals like lion, tiger etc are not important (4) Algae, Snake, Insect, Frog, Mongoose
for ecosystem.
Ans. Algae Insect Frog Snake Mongoose
(2) The place where frogs are more, obviously snakes
(5) Insect, Tree, Fowl, Man
are less in that area.
Ans. Tree Insect Fowl Man
(3) The paddy fields are frequently attacked by
grasshoppers. (6) Goat, Man, Grass
(4) Human existence is totally impossible without Ans. Grass Goat Man
existence of nature. (7) Grasshopper, Snake, Frog, Grass, Eagle
(5) Radioactive pollution can cause tuberculosis. Ans. Grass Grasshopper Frog Snake
(6) Wildlife Protection Act has been established in Eagle
1972. (8) Lion, Deer, Grass
(7) Basic functional unit used to study the ecology is Ans. Grass Deer Lion
called ecosystem. (9) Insect, Green Plant, Frog, Eagle, Snake
(8) Earthquakes are man-made factors affecting Ans. Green Plant Insect Frog Snake
environment. Eagle
(9) UV and IR radiation are natural radiations.
Q.1. (A) 7. Name the following:
(10) Cancerous ulcerations occur due to higher
(1) Secondary Consumers (2) Primary Consumers
radiations of X-rays.
Ans. Frog, Tiger Ans. Deer, Elephant
(11) Environment is made up of one type of ecosystem.
(3) Omnivores (4) Carnivores
(12) The Earth is sufficient to satisfy everyone’s need
but not the greed. Ans. Man, Bear Ans. Lion, Tiger

(13) Sound pollution Control and Prevention Rule (5) Saprophyte (6) Abiotic factors
was established in 2011. Ans. Fungi Ans. Air, Water
(14) A species can be possibly wiped out if there is a (7) Autotrophs (8) Heterotrophs
decrease in the diversity within the species that Ans. Algae, Fern Ans. Rabbit, Lion
reproduce sexually. (9) Biotic factors (10) Air pollutants
(15) Bacteria are generally good decomposers. Ans. Plants, Animals Ans. CO2, CO
(16) All over the world 76 spots are reported as highly (11) Endangered species (12) Largest ecosystem
sensitive biodiversity spots.
Ans. Lion tailed monkey Ans. The Earth
Ans. (1) False. Every component of ecosystem is important.
(13) Rare Species (14) Decomposers
(2) False. If frogs are more, snakes are also more to feed
upon the frogs. (3) True (4) True (5) False. Radioactive Ans. Red panda, Musk deer Ans. Bacteria, Fungi
pollution can cause cancerous ulceration. (6) True (15) International environmental organization.
(7) True (8) False. They are natural factors affecting Ans. International Union for Conservation of Nature
environment. (9) True (10) True (11) False. Environment (IUCN)
is made up of various ecosystems. (12) True (13) False. (16) Forest conserved in the name of God
Sound pollution Control and Prevention Rule was
Ans. Sacred groves
established in the year 2000 (14) True (15) True (16)
False. All over the world 34 spots are reported as highly (17) Voluntary Organizations engaged in
biodiversity spots. environmental activities is India.
Q.1. (A) 6. Complete the following food chain by Ans. Bombay Natural History Society, Mumbai. (BNHS)
arranging in a proper sequence. (18) World’s largest organization engaged in environmental
(1) Cow, Tiger, Grass activities.
Ans. Grass Cow Tiger Ans. Green Peace
(2) Frog, Insect, Grass, Hawk, Snake (19) Diseases caused by radiations
Ans. Grass Insect Frog Snake Hawk Ans. Cancerous ulcerations
66 Master Key Science and Technology Part - 2 (Std. X)

(20) Water pollutants (8) Presently, only % of the Earth’s area has
Ans. Domestic wastes, Industrial effluents been left over with sensitive biodiversity.
(21) Clause for ban on trading rare animals (a) 3.2 (b) 2.3 (c) 6.8 (d) 15.7

Ans. 49A (9) is the largest ecosystem.

Q.1. (A) 8. Make a list of the following: (a) Ocean (b) Earth (c) Pond (d) Lake
(10) The Molai Jungle is located in Kokilamukh of
(1) Animals and plants from jungle ecosystem.
Jorhat district of .
Ans. Animals : Tiger, lion, leopard, moth, mongoose,
(a) Assam (b) Trivandrum
deer, bison, crow, stag, shekhru.
(c) Tehri (d) Ahmedabad
Plants : Teak, berry, jamun, acacia, banyan.
Ans. (1) (b) 34 (2) (c) Red Panda (3) (a) 22nd May
(2) Animals and plants from grassland ecosystem?
(4) (a) 1980 (5) (c) Environmental conservation Act
Ans. Animals : Wolf, rabbit, honeybee, insect, rat, (6) (b) Tehri Garhwal (7) (b) IUCN (8) (b) 2.3 (9) (b)
butterfly, snake, frog, mongoose, fox, Earth (10) (a) Assam.
deer, stag. Q.2.1. Classify the following.
Plants : Grass, shrubs (1) Classify the following into biotic and abiotic
(3) Animals and plants from pond ecosystem. factors:
Ans. Animals : Fish, tortoise, duck, kingfisher, heron, Stone, fungus, soil, green plants, air, fish, water,
sunlight, rat, snake, humidity, frog.
frog, snake, crocodile.
Ans.
Plants : Algae, aquatic plants.
Q.1. (B) Choose and write the correct options: Biotic Factors Abiotic Factors
(1) How many biodiversity spots are reported all Fungus, green plants Stone, soil, air, water,
over the World? fish, rat, snake, frog sunlight, humidity
(a) 30 (b) 34 (c) 35 (d) 40 (2) Classify the following into Primary Consumers
(2) Which of the following belongs to rare species? and Secondary Consumers:
Grasshopper, elephant, frog, deer, fruit eating
(a) Tiger (b) Lion
bats, fox, tiger, giraffe
(c) Red panda (d) Lion tailed monkey Ans.
(3) World Biodiversity day is celebrated on .
Primary Consumer Secondary Consumers
(a) 22 May
nd
(b) 5 June
th

(c) 21st March (d) 22nd April Grasshopper, elephant, Frog, fox, tiger
deer, fruit eating bats, giraffe
(4) The Forest Conservation Act was enacted in
. (3) Classify the following into Air Pollutants and
(a) 1980 (b) 1986 (c) 1972 (d) 1963 Water Pollutants
Industrial waste, hydrogen sulphide, carbon
(5) has been established in 2010 for effective dioxide, domestic wastes, sewage, carbon
implementation of environment related laws. monoxide, dust, asbestos, pesticides used in
(a) Forest Conservation Act agriculture
Ans.
(b) Wild life protection Act
(c) Environmental conservation Act Air Pollutants Water Pollutants
(d) Indian Forest Act Hydrogen sulphide, Industrial waste,
(6) The Chipko centre is a voluntary environmental carbon dioxide, carbon domestic wastes, sewage,
organization located in . monoxide, dust, asbestos pesticides used in
(a) Mumbai (b) Tehri Garhwal agriculture.

(c) Pune (d) Trivandrum (4) Classify the following into Voluntary
Organizations and International Environmental
(7) The ‘Red list’ which contains the names of
Organization:
endangered specis is prepared by .
Chipko Centre, Gandhi Peace Foundation, World
(a) WWF (b) IUCN (c) IPCC (d) UNEP
Environmental Management 67

Wildlife Fund, Bird Life International Centre (7) Primary consumers

for Environment Education, Bombay Natural Ans. The animals which feed exclusively on producers
History Society, Green Climate Fund, Kerala only are called primary consumers.
Science Literature Council, Intergovernment
(8) Secondary consumers
Panel on Climate Change
Ans. The animals which derive their food from primary
Ans. consumers are called secondary consumers.
International
(9) Habitat
Voluntary Organization Environmental
Organization Ans. The place where organisms live and prosper
Chipko Centre, Gandhi World Wildlife Fund, is called as habitat. It is a dwelling place of an
Peace foundation, Centre Bird, Life International, organism.
for Environmental Green Climate Fund, (10) Decomposers
Education, Bombay Intergovernmental Panel Ans. The organisms which decompose the dead
Natural History Society, on Climate Change organisms to derive their food are called
Kerala Science Literature decomposers.
Council (11) Environment
(5) Classify the following into Producers and Ans. Physical, chemical and biological factors affecting
Consumers: the living organisms in any possible way is
Grasshopper, Grass, Frog, Green plants, algae, collectively called as environment.
Tulsi, Tiger (12) Rare species
Ans. Ans. The organisms whose number is considerably
Producers Consumers declined and may become extinct very fast are
called rare species.
Grass, green plants, Grasshopper, frog, tiger
algae, tulsi (13) Vulnerable species
Ans. The organisms which are extremely less in
Q.2.2. Define the following:
number and continue to decline are called
(1) Ecology vulnerable species.
Ans. The science that deals with the study of (14) Endangered species
interactions between biotic and abiotic factors of Ans. The organisms whose number is declined or their
the environment is called as ‘ecology’. habitat is shrunk to such an extent that they can
(2) Bio - diversity be extinct in near future if conservative measures
Ans. Biodiversity is the richness of living organisms in are not implemented are called endangered
nature due to presence of varieties of organisms, species.
ecosystems and genetic variations within a species. (15) Genetic diversity
(3) Ecosystem Ans. Occurrence of diversity among the organisms of
Ans. The biotic and abiotic factors and their interactions same species is called genetic diversity.
with each other form an ecosystem. (16) Species Diversity
(4) Autotrophs Ans. Innumerable species of organisms occuring in
Ans. The organisms which produce their own food are nature is called species diversity.
called autotrophs. (17) Sacred groves
(5) Producers Ans. The forest conserved in the name of God and
Ans. The organisms which can prepare their own food considered to be sacred is called sacred groves.
and make it available for other organisms are (18) Environmental pollution
called producers. Ans. Direct or indirect changes in physical, chemical
(6) Consumers and biological properties of air, water and soil
Ans. The animals which depend on producers or other which will be harmful to humans and other
organisms for food are called consumers. living beings is called environmental pollution.
68 Master Key Science and Technology Part - 2 (Std. X)

(19) Food Chain (iii) It might feed on fruits of the tree as well as insects
Ans. Food chain is the sequence of transfer of energy dwelling there.
in the form of one organism to another. *(6)
What will be the effect on paddy crop if frog
(20) Food Web population declines all of a sudden?
Ans. An ecosystem consisting of many food chains (Let’s Think; Textbook Page no. 37)
interconnected at various levels is called food web. Ans. Paddy crop production will go down as the
Q.2.3. Answer the following population of grasshoppers will increase and
*(1) What is ecosystem? What are its different they will damage the paddy crop.
components? (Can you recall; Textbook Page No. 36) *(7)
Number of which consumers will decline and
Ans. (i) The biotic and abiotic factors at a particular which will increase?
place and their interactions is called an ecosystem. (Let’s Think; Textbook Page no. 37)
(ii) Biotic factors: Plants, animals, microbes
Ans. Primary consumers (Grasshopper) will increase
Abiotic Factors: Water, air, soil, etc.
and tertiary consumers (snake) will decline.
*(2) What are the types of consumers? What are the
criteria for their classification? (Can you recall; *(8) What will be the overall effect on the ecosystem?
Textbook Page No. 36) (Lets Think; Textbook Page no. 37)
Ans. (i) Consumers are classified as primary Ans. The natural balance of the ecosystem will be
consumers, secondary consumers and top level disturbed.
consumers, etc. (ii) These types depend on the *(9) What is environment?
food they eat or prey they feed on. (Can you tell; Textbook Page no. 37)
*(3) Write the relationship between lake and birds Ans. (i) Physical, chemical and biological factors
on tree? (Can you recall; Textbook Page No. 36) affecting the living organisms in any possible way
Ans. (i) Tree near lake comes under lake ecosystem. is collectively called as environment. (ii) In short,
(ii) Birds reside on the trees and may trap prey environment is the condition in surrounding.
from pond. *(10) What is included in environment?
*(4) What is the difference between food chain and (Can you tell; Textbook Page no. 37)
food web? (Can you recall; Textbook Page No. 36) Ans. Environment includes many biotic, abiotic,
Ans. natural and artificial factors.
Food Chain Food Web *(11) Which factors have an effect on the environment?
(i) Interactions between The interconnection (Can you tell; Textbook Page no. 38)
producers, consumers among different Ans.
and decomposers in a food chains in an
(i) Environment is affected by natural factors and
definite sequence is ecosystem at various
artificial factors.
called as a food chain. levels is called as a
food web. (ii) Natural factors: Earthquakes, floods, fires,
(ii) It consists of only one It consists of many droughts etc.
straight chain. interconnected food (iii) Artificial factors: Deforestation, industrialization,
chains. use of excessive pesticides and fertilizers,
*(5) A bird building nest on a tree feeds upon the unorganized garbage disposal, etc.
fishes in nearby pond. Whether this bird is part (iv) These factors cause pollution, create imbalance
of both i.e. tree as well as pond ecosystem? (Let’s and ultimately affect the existence of biotic
Think; Textbook Page no. 37) factors.
Ans. *(12) What will happen if number of consumers in
(i) Yes, bird is a part of both tree as well as pond environment goes on increasing gradually?
ecosystem. (Can you tell; Textbook Page no. 38)

(ii) It feeds upon the fish in the pond and also resides Ans. If number of consumers go on increasing, it
on the tree will affect the population of producers and
Environmental Management 69

other consumers disturbing the balance of the consumers, tertiary consumers, top level (apex)
ecosystem. consumers and decomposers.
*(13) What will be the effect of industry established (19) What is Smog? State its affects.
on river bank on the river ecosystem? (Can you Ans. (i) Smoke and fog together are called smog. (ii) It
tell; Textbook Page no. 38) affects visibility and causes road accidents.
Ans.
*(20) What do we learn from the story of Jadav Molai
(i) The river water will be affected by the chemicals
Peyang?
released as effluents from the industry.
Ans. We can learn from the story of Jadav Molai Peyang
(ii) The animals and plants in the river may die.
that positive attitude towards environment, hard
(iii) The animals and human beings dependent on work with patience and a single person, with
the river water also are seriously affected by the determination can establish a new forest.
polluted water and it will make the soil around
Q.2.4. Write short notes:
the polluted water infertile.
(1) Food chain
*(14) Which are the the types of pollution?
Ans.
(Can you recall; Textbook Page no. 39)
(i) Food chain is a linkage of organisms within an
Ans. The types of pollution are : Air pollution, water
ecosystem, in which each link feeds on the one
pollution, soil pollution, radioactive pollution,
before it and is fed on by the one after it.
thermal pollution, light pollution, noise pollution
(ii) Only the first link in the chain is a producer and
*(15) What do you mean by natural and artificial
all the rest are consumers.
pollution? (Can you recall; Textbook Page no. 39)
(iii) In the ecosystem, the energy is transferred from
Ans. one organism to another with food, in a definite
(i) Unnecessary and unacceptable change in the
sequence.
surrounding environment due to natural events
(iv) Initially, solar energy is absorbed by producers
is called natural pollution. e.g. Forest fires,
and with the help of photosynthesis the food is
volcanoes, tsunami, etc.
synthesized.
(ii) Unnecessary and unacceptable change in
the surrounding environment due to human (v) Energy gets transferred from producers to
activities is known as artificial pollution. consumers of different levels.
eg. Industrialization, deforestation, unplanned (vi) Decomposers derive energy from dead organisms
urbanization, etc. by decomposition from all levels.
*(16) Collect the names of extinct birds and animals (viii) The flow of energy is unidirectional.
of India. (Recall a little; Textbook Page no. 45) e.g. Grass Grasshopper Frog Snake Hawk
Ans. Indian Cheetah, Indian Aurochs, Two-horned (2) Food Web
Rhinoceros, Pink headed Duck, Sivatherium (the
Ans.
tallest and fastest monster) are extinct birds and
animals of India. (i) An ecosystem consists of many food chains that
are interconnected at various levels. This is called
*(17) Which cycles are operated in environment?
What is their importance? (Can you recall; Textbook food web.
Page no. 38) (ii) An organism may be the prey for many other
Ans. organisms.
(iii) For example, an insect feeds upon leaves of
(i) Various cycles operated in the environment are
various plants but the same insect is the prey for
nitrogen cycle, oxygen cycle, carbon cycle, water
different animals like wall lizards, birds, etc.
cycle, etc.
(iv) This forms an intricate web instead of a linear
(ii) Environmental balance is maintained through
continuous operation of various cycles. food chain. Such an intricate network is called as
food web.
*(18) Which are the different trophic levels in the
(v) Generally, food webs are formed everywhere in
food chain? (Can you Recall; Textbook Page No. 36)
nature.
Ans. Producers, primary consumers, secondary
70 Master Key Science and Technology Part - 2 (Std. X)

*(3) Sacred Groves mankind. Such events cause sudden changes in

Ans. the environment and thereby, cause damage to it.
(i) The forest conserved in the name of God and (iii) Disaster is a sudden event that leads to huge loss
considered to be sacred is called as sacred grove. of life and property.
(ii) Sacred groves are in fact ‘Sanctuaries’ conserved (iv) Disaster management is either prevention of
by the society and not by the government forest disasters or making arrangements to face them
department. or at least achieve the abilities to face them.
(iii) As they have been conserved in the name of god, (v) Disasters are never planned but losses due to
they have special protection. them can be prevented in a planned manner.
(iv) These clusters of thick forests are present not only (vi) Disast er management is achieving or time to
in Western Ghats of India but in the entire country. time improving the ability to face the disaster
(v) More than 13000 sacred groves have been through scientific and careful observations and
reported in India. analysis of data.
(vi) They are called ‘Deorai’ in local language and (vii) For example, preparing the action plan through
because of God, people do not cut the trees. This study of various aspects like preventive measures,
helps in their conservation. rehabilitation and reconstruction and executing
*(4) Environmental Conservation that plan is management of disaster.
Ans. (viii) Increasing awareness about disaster management
(i) All the developed, developing and among the general public through training
underdeveloped countries have accepted the programs, mass media etc. will enable them to be
responsibility of environment protection. always prepared for disaster rescue.
(ii) It will be possible to answer the environmental *(6) Chipko Movement of Bishnoi
problems only if environmental protection- Ans.
conservation becomes an effective public (i) In the 1970s, an opposition to the destruction of
movement. forests spread throughout India and came to be
(iii) For this purpose, values like positive attitude and known as the Chipko movement.
affection towards environment, knowledge about (ii) The name of the movement comes from the word
it, etc. should be inculcated among the children ‘embrace’ as the villagers hugged the trees and
since their childhood. prevented the contractors from felling them.
(iv) Human establishments dominate over the nature. (iii) Many communities in India have helped save
In an attempt to live satisfactory life, human kept nature. One such is the Bishnoi community of
on snatching from the nature as much as possible Rajasthan.
and this leads to increase in problems.
(iv) The original chipko movement was started
(v) Environmental conservation is our social around 260 years back in Rajasthan by this
responsibility. community. A large group of villagers led by a
(vi) Various laws are enacted about environmental lady called Amrita Devi laid down their lives in
conservation. Human has a crucial role in an effort to protect the trees from being felled on
environmental conservation. the orders of the Maharaja of Jodhpur.
(vii) These laws are to be implemented strictly and (v) After this incident the Maharaja gave a strong
whoever is a culprit, should be severely punished. royal decree preventing the cutting of trees is all
*(5) Disaster and its management Bishnoi villages.
Ans. (vi) The success achieved by this protest led to similar
(i) Various dangerous events occur many times in protests in other parts of the country.
the environment. These are called disasters. *(7) Biodiversity
(ii) These are ‘all of a sudden’ troubles to the (i) Biodiversity is the richness of living organisms in
Environmental Management 71

nature due to presence of varieties of organisms, Ecosystems are also of two types, natural and
ecosystems and genetic variations within a artificial.
species. Biodiversity occurs at three different (8) Why are green plants called producers?
levels.
Ans. (i) The food which is produced by green plants
(a) Genetic Diversity : Occurrence of diversity can be utilized by others. (ii) They produce food
among the organisms of same species is genetic for the whole ecosystem, hence they are called as
diversity. For example, each human being is producers.
different from the other. (9) What is the purpose of Environmental
(b) Species Diversity : Innumerable species of Conservation Act, 1986?
organisms occur in nature. This is called as Ans. Purpose of the Environmental Conservation Act,
species diversity. Species diversity includes 1986 is to control the pollution and punish the
various types of plants, animals and microbes. persons or institutes harming the environment.
(c) Ecosystem Diversity : Many ecosystems are (10) What is the role of Ministry of Environment
present in each region. Ecosystem is formed and Forests?
through the interaction between plants, animals, Ans. Ministry of Environment and Forests is involved
their habitat and changes in the environment. in planning, inducting and increasing awareness
Each ecosystem has its own characteristic about environment and forests through various
animals, plants, microbes and abiotic factors. programs since 1985.

Q.2.5. Complete the following chart table: (Complete the chart; Textbook Page No. 40)
*(1) Now a day, we are observing the environmental degradation everywhere. Complete the flow chart given
besides with the help of environment.
To maintain biodiversity To Protect rare and endangered species

To maintain balance Need of Environmental To solve the natural and

in the nature conservation artificial problems

To fulfil the future needs of man To minimize air pollution for healthy life.

*(2) Observe the environment around you. Complete the following flow chart. (Observe and fill the information;
Textbook Page No. 38)
Factors affecting environment

Natural factors Man-made factors

Earthquakes, flood, Deforestation, fishing, hunting, poaching,

tsunami, forest fire fire, vehicles, industries, pollution.
Q.2.6. Give scientific reasons: (iii) Cockroach feeds on material from drainage and
(1) Domestic animals like cockroaches, lizards are helps in cleaning the drainage passage.
ecologically important. (iv) Every component of the ecosystem is important
Ans. for the ecosystem, as they form an important link
in the food chain.
(i) Our house is a small ecosystem in which
interactions between biotic and abiotic factors (2) We should take care of the environmental
take place. components of our surroundings.
(ii) Wall lizard feeds on mosquitoes, spider, etc. Ans. Both biotic and abiotic factors are important in
which help in maintaining cleanliness. maintaining ecological balance.
72 Master Key Science and Technology Part - 2 (Std. X)

(i) Our surroundings represent an ecosystem. (iii) Thus, these organisms can manufacture and
(ii) In recent years, due to certain harmful human utilize the food they make.
activities, pollution has increased. (iv) The food they prepare is not only used by them
(iii) Due to this rise in levels of pollution, our health but can be made available to the entire biological
has deteriorated. world, hence are called producers.
(iv) The existence of humans is entirely dependent on (v) Green plants do not depend on others for food
the existence of biotic and abiotic components, and hence, they are called autotrophs.
hence, we must conserve nature. (6) Grasshopper is a primary consumer.
(3) The Earth is the largest ecosystem.
(i) The organisms which feed exclusively on
Ans. producers are called primary consumers.
(i) Ecosystem is an interaction between the biotic (ii) Grasshopper can not produce its own food.
and abiotic factors in the definite geographic area.
(iii) It feeds on grass and other green plants only.
(ii) On the Earth, there are different geographic (iv) Hence, grasshopper is a primary consumer.
locations like oceans, mountains, deserts,
(7) The protection and conservation of wildlife is
grasslands, polar region, etc.
necessary.
(iii) All areas are the separate and individual
Ans.
ecosystems.
(iv) Since the Earth is made of all such ecosystems, it (i) The existence of ecosystem is concerned with
is a huge or the largest ecosystem. the proper interactions between the various
components of the ecosystem.
(4) Environmental problems are increasing in the
recent times. (ii) The biotic factors in the forest are linked to each
other to derive benefits from mutual dependence.
Ans.
(iii) The decrease or increase in the wildlife affects the
(i) Man is the most intelligent animal on this planet.
entire ecosystem adversely. Food chain and food
(ii) On the Earth, human being has proved his
webs get disturbed as prey-predator relationship
superiority as compared to other animals with
is broken.
the help of characters like intelligence, memory,
(iv) Due to this, the entire ecosystem suffers. Hence,
imaginary ability, etc.
we must protect wildlife.
(iii) Humans established their domination over the
(v) Most harmful effects of the environmental
nature.
pollution affect all living organisms including
(iv) Man utilized all the natural resources as much as
wild animals..
possible.
(v) In an attempt to live a satisfactory life, human (vi) Biodiversity is the richness of living organisms in
being kept on snatching from the environment as nature.
much as possible and this leads to disturbance of (vii) Possibility of wiping out the species arises if there
environmental balance. is decrease in the wildlife diversity.
(vi) Hence, environmental pollution is increasing day (viii) Hence, conservation, protection, and cultivation
by day. of wildlife is essential.
(vii) Industrialization, urbanization, deforestation, (8) The flow of energy in the ecosystem is
construction of bridges and dams even housing unidirectional.
lead to create and increase environmental (i) The ultimate source of energy is any ecosystem is
problems. the sun.
(5) Green plants are called autotrophs. (ii) Part of the energy received by an ecosystem from
Ans. the Sun is stored in food molecules by plants.
(i) Green plants absorb solar energy. (iii) When this energy is transferred from one trophic
(ii) In the sunlight, they perform photosynthesis level to another trophic level, some part of energy
in which the food in the form of glucose is is released in the form of heat and some part is
synthesized. utilized for metabolism.
Environmental Management 73

(iv) No energy in the ecosystem goes back to the Sun. (ii) Any unacceptable and unnecessary change in the
(v) Thus, the flow of energy in the ecosystem is surrounding is called environmental pollution.
unidirectional. (iii) Contamination of abiotic components leads to
(9) Decomposers are crucial biotic factors in an environmental pollution.
ecosystem. (iv) Air, water and soil are contaminated by various
Ans. human activities which lead to pollution.
(i) Most decomposers are fungi and bacteria. (v) Population explosion, industrialization,
(ii) In the process of feeding, they use the energy left urbanization, deforestation, overuse of natural
in dead and decaying matter. resources are some of the major causes of
(iii) If decomposers were not the part of ecosystem, environmental pollution.
then the nutrients that entered food chain would (2) Enlist incidences of radioactive pollution? Write
remain locked up forever in the wastes thrown their effects.
out by the bodies of the organisms, and after Ans.
death, in their bodies. (i) Radioactive pollution can occur due to two
(iv) Less and less nutrients would remain available to reasons such as natural and artificial.
plants, and through them, to other creatures.
(ii) UV and IR are natural radiations, whereas X-rays
(v) The waste would go on building up around us till and radiations from atomic energy plants are
all life on earth would be overwhelmed by its own
artificial.
wastes, if the decomposes were not there.
(iii) Chernobyl, Windscale and Three Miles Island
(vi) Thus, decomposers are crucial biotic factors of
incidences are the major mishaps of the present
ecosystems.
world.
(10) In the ecosystem wild animals like lions, tigers, (iv) Effects of radiations:
are important. (a) Cancerous ulceration occur due to higher
Ans. radiations of X-rays.
(i) In the forests, the green plants play the role of (b) Tissues in the body are destroyed.
producers. They perform photosynthesis and (c) Genetic changes occur.
produce food which is available for herbivores. (d) Vision is adversely affected.
(ii) Herbivores feed on green plants and satisfy their
*(3) Write the types and examples of biodiversity.
energy requirement and they become food for
Ans.
carnivores.
(iii) Lion, tigers are secondary or top level consumers (i) Biodiversity is the richness of living organisms in
which feed on herbivores. nature due to presence of varieties of organisms,
(iv) In order to maintain ecological balance, every ecosystems and genetic variations within species.
organism is necessary. If there are no wild animals, (ii) Biodiversity occurs at three different levels.
then the number of herbivores will increase (a) Genetic Diversity: Occurrence of diversity
beyond certain limit which may affect the green among organisms of same species whose members
plants. involve in sexual reproduction is genetic diversity.
(v) Hence, predators like lion and tiger are important (b) Species Diversity: Innumerable species of
to prevent the overpopulation of herbivores. organisms occur in the nature. This is called
Q.3.1. Explain the following questions. species diversity. Species diversity includes
various types of plants, animals and microbes.
(1) Explain various causes of environmental
pollution? (c) Ecosystem Diversity: Many ecosystems are
present in each region. Ecosystem is formed
Ans.
through the interactions between plants, animals,
(i) Contamination of any material is called as pollution.
microorganisms, and abiotic factors.
74 Master Key Science and Technology Part - 2 (Std. X)

(4) How are threatened species classified? OR (iii) Electrical appliances can be switched off when
What are the different types of threatened not in use. Switch off fans, A.C’s, while leaving
species? the room.
Ans. Classification of threatened species: (iv) Dry and wet garbage should be kept and disposed
(i) Endangered species: Either number of these off separately.
organisms is declined or their habitat is shrunk (v) Use eco-friendly fuel and renewable energy
to such an extent that they can be extinct in sources.
near future if conservative measures are not *(8) How can bio-diversity be conserved?
implemented.
Ans. Biodiversity can be conserved in the following ways:
Example: Lion tailed monkey, lesser florican
(i) Protecting rare species of organisms.
(ii) Rare Species: Number of these organisms is
(ii) Establishing national parks and sanctuaries.
considerably declined. Organisms of these species
being endemic may become extinct very fast. (iii) Declaring some regions as ‘bioreserves’.
(iv) Projects for conservation of special species.
Example: Red panda, musk deer.
(v) Conserving all plants and animals.
(iii) Indeterminate species: These organisms appear
to be endangered but due to some of their (vi) Maintaining records of the traditional knowledge.
behavioural habits (like shyness) there is no (vii) Obeying the rules.
definite and substantial information. (9) How do the interactions take place in the biotic
Example: Giant squirrel (Shekhru) and abiotic factors of ecosystem?
(5) What are abiotic factors? Write examples. Ans.
Ans. All inanimate and non-living things are together (i) Biotic factors of the ecosystem use abiotic
termed as abiotic factors. components for the manifestation of their life
Abiotic factors are divided further into physical processes.
and chemical factors. (ii) Similarly, biotic factors release some materials
(a) Physical components: Sunlight, Temperature, as excretory products from their bodies to the
Heat, pressure, humidity. environment and also release materials after their
(b) Chemical components: Air, water, soil, minerals, death.
gases, chemical compounds. (iii) Due to these continuous reactions, the abiotic
(6) Enlist the effects of excessive use of natural components of the ecosystem keep on fluctuating.
resources. (iv) In any ecosystem, the existence of biotic components
Ans. Excessive use of natural resources have following is entirely dependent on the abiotic components.
adverse effects: (v) In this way, there are continuous interactions
(i) The life of animal and plant is threatened. between biotic and abiotic factors of the
(ii) Many species got extinct from the Earth and some environment.
species became endangered. (10) Explain the role of producers in the food chain?
(iii) Due to deforestation, many varieties of medicinal Ans.
plants are lost. (i) Every component of the food chain needs energy.
(7) Suggest some measures at individual level, a (ii) Food is a source of energy.
person can follow to protect the environment (iii) Green plants trap solar energy and carry out
Ans. On an individual level, a person can take certain photosynthesis to form glucose.
measures: (iv) As green plants prepare their own food and do
(i) Use eco-friendly materials at home instead of not depend on others for food, they are called
synthetic materials. autotrophs.
(ii) Rain water harvesting at domestic level should be (v) The food which they prepare is not simply utilized
undertaken. by them but utilized directly or indirectly by
Environmental Management 75

other living organisms. Hence, the green plants *(14) How do butterflies contribute to environmental
are called producers. balance? (Search; Textbook Page no. 41)
(vi) In the process of photosynthesis, oxygen gas is Ans.
released in the atmosphere which is available to (i) Butterflies pollinate different types of flowering
other organisms for respiration. plants, thus helping in the reproduction of plants.
*(11) What is energy pyramid? (ii) Butterflies play an important role in food chain
as prey for birds, bats and other insectivorous
Ans.
animals.
(i) Energy pyramid is a graphical model which
(iii) By feeding on leaves, butterflies can help to
represents the flow of energy in a community.
control some of the unwanted plants found in the
(ii) It consists of different levels which represent garden.
different group of organisms composing a food
(iv) Butterflies have been widely used by ecologists as
chain. model organisms to study the impact of climate
(iii) The energy pyramid shows the process of energy change.
travelling up a food chain. (v) By watching how butterflies react and adjust to
(12) What happens if there are no decomposers on environmental changes, scientists can determine
the Earth? the effects of various actions on the environment
Ans. as a whole.
(i) Every component of the ecosystem plays a *(15) Recognize the following food chain - Describe
significant role in it. the ecosystem to which it belongs.

(ii) Decomposers have a role of returning the Grasshopper snake Paddy field
Eagle Frog.
material from the dead organism to the nature by
Ans.
the process called decomposition.
(i) Paddy field Grasshopper Frog
(iii) If decomposers are absent, this process will not
Snake Eagle
take place and the Earth will see dead bodies
(ii) This food chain belongs to Paddy field ecosystem.
everywhere, thus increasing garbage.
It is a man-made ecosystem.
(iv) If materials are not returned to the surroundings,
(iii) Paddy is cultivated on large scale in various states
then they are not made available for recycling. of South India.
(v) Ultimately ecosystems would be buried under a (iv) Paddy fields are frequently attacked by
heap of garbage. grasshoppers.
(13) Pollution depletes the quality of air. Explain (v) Similarly frogs are also present in large numbers
with suitable example. in the mud of paddy fields to feed upon
grasshoppers and snakes are also present therein
Ans.
to feed upon their favorite food. i.e frogs.
(i) The air pollution definitely depletes or reduces
(vi) Eagles feed on snakes which keeps a check on the
quality of air.
number of snakes, in the ecosystem.
(ii) In metropolitan cities, due to heavy traffic *(16) What is the meaning of “Jivo Jivasya Jivanam”?
and industrialization various gases add to the
Ans.
surrounding air.
(i) Jivo Jivasya Jivanam means that living things are
(iii) Indiscriminate disposal of such gases increase interconnected to each other.
CO2 level of air. (ii) One life on earth is food for anothers.
(iv) As any particular component of air gets increased (iii) Producers produce food which is used by primary
beyond certain limit, the air gets affected. consumers
(v) Industries add 50% more CO2 than what exists (iv) They are food for secondary consumers and so
on.
naturally, this is known as quality disintegration
(v) If any link in the food chain is disturbed, the
or a quality decay.
entire food chain is affected.
76 Master Key Science and Technology Part - 2 (Std. X)

Q.3.2. Complete the chart / table:

*(1) Based on the air pollution, water pollution and soil pollution, complete the following chart. (Complete the
chart; Textbook Page No. 39)

Air Pollution Water Pollution Soil Pollution

Components Gases: CO2, CO, hydrocarbon, NH3, free Cl2, H2S, O3, Leftover food, paper
sulphur, NO2, hydrogen phosphene (PH3) hot water, scraps, old clothes, bottles,
sulphides, etc colour, soap, wax, mercury, tins, plastic articles, tar
Solid : Dust, ash, carbon, etc. construction work waste,
lead, asbestos, etc. ash, biomedical waste
Source Vehicles, chemical industries, Industrial wastes, domestic Mines, metallurgy, thermal
industries, use of pesticides waste, sewage, chemicals power station, domestic
in agriculture, CFC from discharged from industries, waste, hospitals. E-wastes
refrigerator, road mix material pesticides used in plastic wastes from
agriculture. industries.
Effect Irritiation of eyes due to SO2, Inflammation in the Soil erosion, retarded
CO, CO2, inflammation of abdomen, loss of brain growth of plants/crops,
respiratory tract, respiratory power death of aquatic nutritional deficiency etc.
disorder, depletion of capacity animals, water borne
to hold O2 in blood, cancer, diseases in humans.
tuberculosis, acid rain.
Control Measure (i) Use well tuned machinery. (i) Do not waste water (i) Restrict the use of plastics.
(ii) Prevent incomplete (ii) Do not release hot water (ii) Wet garbage should be
oxidation. in water bodies. given treatment to make
(iii) Minimize the use of (iii) Industrial effluents manure from it.
pesticides in agricultural should be treated. (iii) Do not litter public
practices (iv) Not to use pesticides places.
(iv) Construct tall chimneys or insecticides in the (iv) Plantation and cultivation
(v) Encourage tree plantation agricultural. of trees.
and cultivation. (v) Recycling

*(2) Fill up the blank boxes and display the completed chart. (Complete the chart; Textbook Page No. 37)

Ans. Ecosystem

Abiotic components Biotic components

Physical factors Chemical factors Autotrophic Heterotrophic

Air, water, vapour, Producers Animals Decomposers

Nutrients
soil, sunlight,
minerals Green Plants Consumers Bacteria

Inorganic Organic Primary Secondary Tertiary

substances substances

Hydrogen, oxygen, Proteins,

nitrogen, calcium, iron, carbohydrates, fats
sodium, potassium
Environmental Management 77

Q.4.1. Answer in detail: various factors of the environment and ultimately

*(1) Explain the statement- ‘We have got this Earth affects the existence of biotic factors.
planet on lease from our future generations and (v) The main threat to the ecosystem is the pollution
not as ancestral property from our ancestors’. of materials present in it. Sometimes it may
Ans. damage the ecosystem completely in the course
(i) Existence of man is entirely dependent on the of time.
existence of ecosystem. (vi) In environment management, we take the task
(ii) Man derives his benefits by using various of protecting, conserving and preserving the
components of the ecosystem. natural components of the ecosystem.
(iii) We can get these materials easily from the nature as (vii) If we control the pollution, then the environmental
our ancestors protected and conserved them for us. management activities will succeed and the
(iv) Today man has proved his superiority as purpose will be served.
compared to other animals. He is indiscriminately (viii) If there is minimum pollution, then the nature
using the natural resources for personal greed. cycles will continue without any disturbance and
(v) Due to this, future generations may not benefit biodiversity can be enriched.
from the nature. They will suffer from pollution, *(3) Which projects will you run in relation to
drought, unseasonal rains, green house effect etc. environmental conservation? How?
(vi) Thus, it is our responsibility to preserve, conserve Ans.
and protect nature so that next generations will (i) Project (1): Tree plantation and cultivation: This
get conducive climate and their life may not be in program is necessary as only if people come to
trouble. know the importance of a tree, plantations will
(vii) Thus it is rightly said that, we got the planet earth increase and ‘cutting the trees‘ will never take
on lease from our future generations and not place.
ancestral property. (ii) Project (2): Save water: In this project, people and
(viii) Nature is not our ancestral property but we have students will be made aware of the importance
to take care of it so that it can be handed over to of water. At the same time, various methods of
next generations without any further damage to it. water conservation will be taught.
*(2) How will you justify that overcoming the (iii) Project (3): Wildlife conservation: Various places
pollution is a powerful way of environmental like sanctuaries, national parks can be visited to
management? know more about the wild animals and we can
OR make efforts to protect them.
*Why is it said that pollution control is important? (iv) Project (4): Minimise or avoid use of plastic: With
(Use your brain power; Textbook page No. 40) this activity, we can create awareness about the
Ans. hazards of plastic and various programs can be
(i) Natural environment consists of air, atmosphere, conducted to create awareness about minimizing
water, land, living, organisms, etc. use of plastic and conserving the environment.
(ii) Continuous interactions occur between biotic *(4) What would be your role in environment
and abiotic factors. Their interactions are very management? (Think and answer; Textbook Page
important. No. 44)
(iii) Environmental balance is maintained through Ans.
continuous operation of various natural cycles (i) Attempts at various levels are performed for
like biogeochemical cycles. conserving environment.
(iv) When some natural factors of environment (ii) Some levels are as follows:
and some artificial polluted factors harm the (a) Conservation: Conserving the available
environment, it creates imbalance between resources.
78 Master Key Science and Technology Part - 2 (Std. X)

(b) Control: Preventing the harm, stopping (iii) Wood, medicinal plants, gums, resins are the
harmful activities, changing the mindset. plant products which are useful, hence plants are
(c) Production: Attempting innovation, revival brutally cut.
of harmed factors of environment. (iv) Animals and plants have demand abroad for
(d) Prevention: Preventing possible harms, research and for medicines. Due to this, hunting
factors harmful to environment and designing takes place which resulted in making certain
new plans. varieties endangered.
(e) Preservation: Preserving whatever has been (v) Because of all these reasons, certain animals and
leftover, remedies to prevent further loss, plants became endangered.
preserving unknown regions. (vi) We can save the remaining animal and plant life
(f) Awareness: Education, Guidance, Awareness, through environmental education, awareness
Imitation, Organization, Participation. programs, strict rules and regulations,
*(5) Write the names of biodiversity hot spots? implementing various environmental acts, and
Ans. prohibiting poaching can prevent the loss of
(i) There are 34 highly sensitive biodiversity spots varieties of plants and animals.
which are reported all over the world. Such areas *(7) Why does human being have an important
had once occupied 15.7% area of the Earth. place in the environment?
(ii) At present, 86% of the sensitive areas are already Ans.
destroyed
(i) Since the existence of human, there is inter
(iii) Some animals from the Western Ghats spread
relationship between human and environment.
over the states of Gujarat, Maharashtra, Goa,
Tamilnadu and Kerala have been endangered (ii) Humans evolved on the Earth long after
due to mining industry and search for natural formation of the Earth.
gas. (iii) Human beings proved their superiority as
(iv) Habitats of Asiatic Lion and Wild Bison of this compared to other animals with the help
region have been under threat. of characteristic like intelligence, memory,
(v) Manas Sanctuary of Assam is under threat due to imagination etc. Humans established
dams and indiscriminate use of water. Tiger and domination over the nature.
Rhino of that region, are under threat. (iv) They utilized all the natural resources as much
(vi) Sunderban Sanctuary of West Bengal is reserved as possible and this lead to increase in problems.
for tigers. However, the tiger population and
(v) From this entire scenario, we can understand
overall local environment is seriously challenged
that the human being has crucial role in
by dams, deforestation, excessive fishing,
maintaining the environmental balance.
trenches dug for the same, etc.
(vi) If he has disturbed the environmental balance,
*(6) Which are the reasons for endangering the
then he himself only can conserve and improve
species of plants and animals? How can we save
the quality of nature.
those?
Ans. Numerous species of animals and plants have (8) Mahatma Gandhi said, ‘ The Earth is sufficient
become endangered due to activities of human to satisfy everyone’s need but not the greed’
beings. Explain.
(i) Animals and plants are the sources of income for Ans.
some people. Hence, poaching takes place which (i) There are different types of biotic and abiotic
becomes a big threat to the existence of animal factors on the earth.
and plant life. (ii) There are different types of ecosystems found
(ii) Animal skin, flesh and bones are used for various with lot of variety in them as per their abiotic
purposes and thus they are killed. components.
Environmental Management 79

(iii) Diversity in biotic factors depends on availability *(2) Some symbols are given below. Find the meaning
of abiotic factors. of those symbols in relation to environment
(iv) Various bio-geochemical cycles naturally going conservation. Make a list of other such symbols.
on in nature which maintain the natural balance (Enlist and Discuss; Textbook Page No. 43)
of the ecosystems. (a)
(v) If use of any such factors is indiscriminately Ans. This sign indicates ‘Waste
increased, there can be imbalance which leads to Management’.
pollution.
(vi) Man uses the nature the most to satisfy his needs.
In the course of time, he has become greedy.
(vii) Human activities like deforestation, road
construction, industrialization, unplanned Fig. 4.4
urbanisation lead to loss of biodiversity as well as
environmental pollution. (b)
(viii) Mahatmaji’s vision was that human should
use nature only for basic needs and not for the Ans. This sign indicates
development at the cost of nature. ‘Save Energy’.
(ix) There should be sustainable development without
harming the environment.
Q.4.2. Observe and explain the diagram.
*(1) What are the meanings of following symbols? Fig. 4.5
Write your role accordingly?
*(a) (c)
Ans. This sign is used for
indicating that ‘this Ans. This sign indicates
object can be reused and ‘Save fuel’.
recycled’.
We can collect and give it
to rag pickers. Fig. 4.6
Fig. 4.1
*(b) (d)
Ans. This sign is used to
indicate ‘Save Water’. Ans. This sign indicates
We must close the taps ‘Save water’.
which are left open, not
to waste water.

Fig. 4.2 Fig. 4.7

*(c)
(e)
Ans. This sign indicates ‘Solar
Panel’. Ans. This sign indicates
We can save energy by ‘Ban Plastic’.
using solar energy.

Fig. 4.3 Fig. 4.8

80 Master Key Science and Technology Part - 2 (Std. X)

*(3) Observe the and answer the following

questions. LION KITE
Ans. TIGER
Frog
(Secondary SNAKE
Consumer
Sun
Grasshopper WOLF
(Primary
Producer) DEER
FROG

Snake GOAT
Grass (Tertiary
(producer) consumer GRASS GRASS HOPPER

Eagle
(Decomposer act on all levels)
(Apex
Bacteria consumer (5)
and fungi
(Decomposer

Fig. 4.9 Food chain

(a) Write the name and category of each of the
component shown in picture. (Think and answer;
Textbook Page No. 36)
Ans. Grass (producer), Grasshopper (primary
consumer), Frog (Secondary consumer), Snake Fig. 4.10. Jadav Molai Payeng
(Tertiary consumer), Eagle (Apex consumer),
(a) Who is this Man in the above picture?
Microbes (Decomposers).
(b) What is necessary to convert this food chain Ans. The man in the picture is Jadav Molai Payeng.
into food web? (Think and answer; Textbook Page (b) What was his contribution for?
No. 36) Ans.
Ans.
(i) The 1979, the local social forestry Department in
(i) Include more primary consumers like squirrel,
Assam began a social aforestation project in 200
deer, goat etc.
hectares of land.
(ii) Include more secondary consumers like wolf, fox
etc. (ii) Even after completion of the project, Molai single
(iii) Include more tertiary and apex consumers like handedly continued to plant the trees.
lion, tiger etc. (iii) At present, the barren area is covered with trees
(iv) Show interrelationship of these animals to to about 1360 acres.
convert the food chains into a food web. (iv) We learn that even if many people come together
*(4) Prepare a food web of atleast 3 food chains. to destroy a forest, a single person if determined
Ans. Grass → grass hopper → frog → snake → kite can make a difference and create a new forest.
Grass → dear → tiger (v) In any environmental projects do not think what
Grass → goat → wolf → lion can you do ? Think if you do, then others around
you will follow you.

vvv
Environmental Management 81

ASSIGNMENT - 4
Time : 1 hour Marks : 20

Q.1. (A) Answer the following. (3)

(1) Fill in the blanks: The World Biodiversity Day is .................. .
(2) Find the odd man out: Deer, tiger, frog, lion.
(3) Complete the analogy:
Rare species : Musk deer : : Indeterminate species : ..................
Q.1.(B) Choose and write the correct options: (2)
(1) How many biodiversity spots are reported all over the World?
(a) 30 (b) 34 (c) 35 (d) 40
(2) has been established in 2010 for effective implementation of environment related laws.
(a) Forest Conservation Act (b) Wild life protection Act
(c) Environmental conservation Act (d) Indian Forest Act
Q.2.Answer the following (Any 2) (4)
(1) Define: (i) Biodiversity (ii) Secondary consumers
(2) Write the differences between food chain and food web.
(3) Green plants are called autotrophs - Give scientific reasons.
Q.3.Answer the following (Any 2) (6)
(1) Enlist incidences of radioactive pollution. Write their effects.
(2) Label the figure.

Food Chain

(3) How would you conserve environment?
Q.4.Answer in detail (Any 1) (5)
(1) How are the threatened species classified?
(2) ‘We have got this Earth planet on lease from our future generations and not as ancestral property
from our ancestors.’ - Explain this statement.

vvv
 5 Towards Green Energy

Points to Remember:
• ‘Energy is a stored ability or capacity of a body to do work.’ Hence, in order to carry out work, we need
energy.
• The energy required to perform mechanical work, is called mechanical energy. It is of two types; namely,
potential energy and kinetic energy.
• Energy can be converted from one form to another. The total energy in the universe always remain constant.
• Most of the electric power plants are based on the principle of electromagnetic induction invented by Michael
Faraday. According to him, whenever magnetic field around a conductor changes, a potential difference is
generated across the conductor.
• The magnetic field around a conductor can be changed in two ways. If a conductor is stationary and magnet
is rotating, the field around conductor changes or if a magnet is stationary but the conductor is moving then
also the field around the conductor will change. Thus in both the cases, a potential difference is produced
across the conductor.
• The electric power generating machine based on this principle is called ‘electric generator’.
• The electric generator converts mechanical energy into electrical energy.
• In the thermal power stations, coal is burnt and heat energy is then converted to electrical energy. Here,
chemical energy of coal is first converted into heat and then into kinetic energy of steam and ultimately to
electrical energy.
• Thermal power plant has boiler, turbine, generator, condenser, etc.
• Due to thermal power plants CO2, SO2, NO2, carbon particles are added to air resulting in air pollution.
• In the nuclear power plant, steam turbine is used to rotate the generator. However here, the energy released by
fusion of nuclei of atoms like Uranium or Plutonium is used to generate the steam of very high temperature
and high pressure.
• In the nuclear power plant, the nuclear energy is first converted into thermal energy, then thermal energy
is converted into kinetic energy of steam, then kinetic energy of steam is converted into kinetic energy of
turbine and finally kinetic energy of turbine is converted into electrical energy.
• When a slow moving neutron is bombarded on uranium nucleus, the splitting of uranium nucleus takes
place, Barium and Krypton nuclei are formed with release of three neutrons, with release of tremendous
amount of energy, this process is called ‘nuclear fission’.
• The products after fission of nuclear fuel are also radioactive and emit harmful radiations.
• In the power generation plant based on natural gas, the turbine is run by a gas at very high temperature and
pressure generated by combustion of a natural gas.
• In this plant, pressurised air is introduced into the combustion chamber using a compressor, Natural gas is
burnt in the chamber at very high temperature and pressure generated in this chamber runs the turbines. The
turbine then drives the generator to produce electricity.

(82)
Towards Green Energy 83

• The efficiency of power plant based on natural gas is more than thermal power plant. Even the air pollution
is greatly reduced.
• In Hydroelectric power plant, the potential energy in water stored in dam is converted into kinetic energy
of water. This kinetic energy drives the turbines. The turbines drive the generator to produce electricity.
• Since no fuel is burnt in hydro-electric power generation, there is no pollution, but obstruction of water
affects living world in the river.
• Wind energy can also be used to obtain electrical energy.
• The machine that converts the kinetic energy of wind into electrical energy is called wind-turbine.
• Wind energy is a clean source of energy.
• The electrical energy can also be generated by using solar energy. This can be done by two ways, solar
photo-voltaic cells and Solar thermal power plant.
• In solar photovoltaic cells, the electricity is generated without using generator and without using principle
of electro-magnetic induction. Photovoltaic cells convert the solar radiation energy directly into electrical
energy.
• In the second method, the energy of solar radiations is converted into thermal energy first. Then the
turbine-generator system is driven using that thermal energy to generate electricity.
• Solar energy is the most eco-friendly energy.

(12) If 36 solar cells, each of size 100 cm2 are

MASTER KEY QUESTION SET - 5
connected in series in a solar panel, it will give
Q. 1. (A) 1. Fill in the blanks and rewrite the statement: potential difference of V and current of
A.
(1) The principle of was invented by
Michael Faraday. (13) A transformer transforms the and
(2) To rotate the magnet in the generator, we need a current levels of the generated power.
device called (14) Incomplete combustion of fossil fuels leads to
(3) The water in a cooling tower in thermal power formation of gas which adversely
plant is circulated through the . affects our health.
(4) In thermal power plants, the energy (15) An electronic device that convents D.C. Solar
in the coal is converted into electrical energy power into AC power is called .
through several steps. (16) and fuels are obtained from
(5) In nuclear fission, the energy released by fission Natural gas.
of nuclei of atoms like and Ans. (1) electro magnetic induction (2) turbine (3) condenser
is used. (4) chemical (5) Uranium and Plutonium (6) Sulphur
(6) Natural gas does not contain element , (7) kinetic (8) Wind velocity (9) 30 (10) Semi
so burning of natural gas results in less pollution. conductor (11) array (12) 18, 3 (13) voltage (14)
(7) In Hydroelectric plants, the energy of carbon monoxide (15) inverter (16) LPG, CNG
the flowing water drives the turbine
Q. 1. (A) 2. Find the odd one out:
(8) is a factor necessary for wind - energy
(1) Boiler, turbine, generator, solar cell.
generation, but is not available everywhere.
Ans. Solar cell: It is part of Solar power station while,
(9) A silicon solar cell of dimension 1 cm2 generates
others are parts of thermal power station.
current of about mA.
(2) Thermal energy, atomic energy, wind energy,
(10) Solar cells are made of a special type of material
called such as silicon. natural gas power.

(11) Many solar panels connected in series form a Ans. Wind energy: It is clean source of energy while
solar strings and many solar strings connected in others create air pollution.
parallel form a solar .
84 Master Key Science and Technology - 2 (Std. X)

(3) Uranium, plutonium, coal, thorium. (6) Water stored in dam : Potential energy : : Flowing
Ans. Coal - It is a fuel used is thermal power plant water : .
while others are used as fuels in nuclear power Ans. Kinetic energy - Water stored in dam is an
plant example of potential energy and flowing water is
(4) Flowing water, water stored in dam, moving fan, an example of Kinetic energy.
running train.
(7) Atomic power plant : Steam turbine : : Natural
Ans. Water stored in dam: It is an example of potential
energy, while others are examples of kinetic power plant : .
energy. Ans. Gas turbine - The turbine used in atomic power
(5) LPG, CNG, coal, methane. plant is rotated using steam and the turbine used
Ans. Coal: It is solid fuel while others are gaseous in thermal power plant is rotated using gas.
fuels. (8) Inverter : DC to AC : : Photovoltaic cell : .
(6) Edible oil, LPG, CNG, crude oil. Ans. Solar energy to Electrical energy - Inverter
Ans. Edible oil: It is used in food products, while converts the DC current to AC current while
others are used as fossil fuels. photovoltaic cell converts solar energy to
(7) Solar energy, nuclear energy, tidal energy, wind electrical energy.
energy.
Q. 1. (A) 4. Match the columns and complete the
Ans. Nuclear Energy: It creates nuclear pollution
while others are clean sources of energy. table:
(8) Carbon dioxide, oxygen, sulpur dioxide, nitrogen *(1) Column ‘A’ Column ‘B’ Column ‘C’
dioxide. (1) Coal (a) Potential (A) Wind
Ans. Oxygen: It is a pure gas while others are harmful energy electricity plant
gases released by burning of coal.
(2) Uranium (b) Kinetic (B) Hydro electric
Q. 1. (A) 3. Find out the correlation: energy plant
(1) Thermal power plant : Coal : : Nuclear power
(3) Water (c) Nuclear (C) Thermal plant
plant :
reservoir energy
Ans. Uranium - Coal is used as a fuel to generate
(4) Wind (d) Thermal (D) Nuclear
energy in a thermal power plant whereas
energy power station
uranium is used as a fuel to generate energy in
Nuclear power plant. Ans. (1 - d - C) ; (2 - c - D) ; (3 - a - B) ; (4 - b - A)
(2) Series arrangement of modules : Strings : : parallel
(2) (2) Column ‘A’ Column ‘B’ Column ‘C’
arrangement of string :
Ans. Solar array - Many modules are connected in (1) Electromagnetic (a) Silicon (A) Uncontrolled
series to form solar strings while many solar induction chain
strings are connected in parallel to form a solar (2) Nuclear plant (b) Heat from (B) DC
array. coal
(3) Coal consumption of world : 41% : : coal
(3) Photovoltaic (c) Faraday (C) Chemical
consumption in India :
cell energy
Ans. 60% - The coal consumption of the world is 41%
whereas coal consumption of India is 60%. (4) Thermal power (d) U - 235 (D) Changing
(4) Natural gas : CNG and LPG : : Nuclear power : plant magnetic field

Ans. (1 - c - D) ; (2 - d - A) ; (3 - a - B) ; (4 - b - C)
Ans. Uranium and plutonium - CNG and LPG are
used as fuels in Natural gas power plant whereas (3) Column ‘A’ Column ‘B’
uranium and plutonium are used as fuels in a
(1) Thermal power (a) Only avalible in day time
nuclear power plant.
(5) Silicon solar cell of 1 cm2 : 30 mA : : 100 cm2 : (2) Wind power (b) Air pollution
.
(3) Solar power (c) Atomic radiation
Ans. 3A - A silicon solar cell of dimension 1 cm2
generates current of about 30 mA while silicon (4) Atomic power (d) Wind velocity
solar cell of dimension 100cm2 generates current
of about 3A. Ans. (1 - b); (2 - d); (3 - a); (4 - c)
Towards Green Energy 85

(4) (15) Solar cells are made up of Silicon.

Column ‘A’ Column ‘B’
Ans. (1) False. Coal has chemical energy. (2) False. Water is
(1) Series of solar cells (a) Solar cell
boiled using boiler. (3) True. (4) False. Uranium is the
(2) Series of solar panels (b) Solar String fuel used in nuclear reactor. (5) False. The atomic reaction
(3) Solar strings in parallel (c) Solar panel carried out in the nuclear reactor is a type of controlled
(4) semiconductor silicon (d) Solar array chain reaction. (6) False. It gets converted into U-236.
(7) True. It is a clean source as there is no combustion.
Ans. (1 - c); (2 - b); (3 - d); (4 - a) (8) False. The efficiency of natural gas plant is more
(5) Column ‘A’ Column ‘B’ than that of thermal power plant that works on coal.
(9) False. The energy released during fission is measured
(1) Thermal power (a) CNG
in MeV. (10) False. The product after fission of nuclear
station.
fuel are radioactive and emit harmful radiation. (11)
(2) Nuclear power station (b) Coal False. Acid rains are caused by Nitrogen dioxide (12)
True. (13) False. It depends on wind velocity. (14) False.
(3) Solar cell (c) Uranium 3 neutrons and Barium and Krypton. (15) True.
(4) Natural gas power (d) Silicon Q. 1. (A) 6. Answer the following in one sentence.
*(1) What is Energy?
Ans. (1 - b); (2 - c); (3 - d); (4 - a)
(Can you recall Text book pg no. 47)
Q. 1. (A) 5. State whether the following statements are Ans. Energy is the capacity or stored ability of a body
true or false and correct the false statement: to do work.
(1) There is heat energy stored in coal. (2) Write the types of mechanical energy?
(2) In thermal power plant water is boiled using Ans. Mechanical energy is of two types potential
cooling tower. energy and kinetic energy.
(3) In thermal power plant, turbine rotates because (3) Where can we install wind turbines?
of steam. Ans. The wind velocity is usually high near the sea
(4) In the nuclear reactor, aluminium is used as a shore. Therefore, we can install wind turbines
fuel. there.
(4) Can electrical energy be generated without using
(5) The reaction in the atomic reactor is a type of
the principle of electromagnetic induction?
uncontrolled chain reaction.
Ans. Yes, Solar radiation using solar cells.
(6) If U-235 is bombarded with a neutron, it gets
(5) What is meant by Green energy? Give examples
converted into U-237.
of green energy?
(7) Atomic energy is a very good energy source.
Ans. Green energy is the eco-friendly form of energy
(8) The efficiency of natural gas plant is less than that which does not cause environmental pollution.
of thermal power station working on coal. Examples: Solar energy, wind energy,
(9) Energy released during fission is measured in Hydroelectricity etc.
joules. *(6) Which electricity generation process is
(10) The product after fission of nuclear fuels are eco-friendly and which is not?
harmless. (Lets think Text book pg no. 52)
(11) Carbon dioxide generated due to buring of fuels Ans. Wind mill, solar thermal plant are eco-friendly
like coal, diesel leads to problems like acid rain. while thermal and nuclear power generation are
not eco-friendly.
(12) In wind turbine the function of the gearbox is to
Q. 1. (B) Choose and write the correct option:
increase rotations per unit time
(1) Electromagnetic induction was discovered by
(13) Wind turbine of specific capacity is selected
.
depending on altitude.
(a) Edison (b) Newton
(14) In Nuclear fission, Uranium 236 releases two
(c) Michael Faraday (d) Archimedes
neutrons and converts into Barium and krypton.
86 Master Key Science and Technology - 2 (Std. X)

(2) In combustion of coal gas is not released. Q.2.1. Define the following:
(a) SO2 (b) NO2 (c) NH3 (d) CO2 (1) Electric generator
(3) Each nuclear fission of uranium nucleus releases Ans. The device that converts mechanical energy to
neutrons. electrical energy is called an Electric Generator.
(a) one (b) two (c) three (d) four (2) Thermal power plant
(4) Water stored in the dam possess energy. Ans. The plant in which thermal energy is used to
(a) chemical (b) potential generate electrical energy is called thermal
power plant.
(c) kinetic (d) electric
(3) Nuclear power plant
(5) The electric energy obtained from solar
photovoltaic cell is of type. Ans. The plant in which the nuclear energy is used to
generate electrical energy is called nuclear power
(a) DC (b) AC
plant.
(c) static (d) magnetic
(4) Green energy
(6) Solar cell can work during only.
Ans. The energy generated by using wind, water,
(a) night (b) morning sunlight which is environment friendly is called
(c) day time (d) evening green energy.
(7) Each nuclear fission of uranium nucleus release (5) Solar photovoltaic effect
energy.
Ans. Solar photovoltaic cell converts the solar radiation
(a) 20 MeV (b) 236 MeV energy directly into electrical energy. This effect
(c) 237 MeV (d) 200 MeV is called solar photovoltaic effect.
(8) Wind turbines with capacity right from less than (6) Solar panel
to about are commercially Ans. Many solar cells come together to form a solar
available. panel.
(a) 1 kW, 7000 kW (b) 10 kW, 700 kW (7) Solar string
(c) 1 MW, 700MW (d) 1 kW, 10kW Ans. Many solar panels connected in series form a
(9) A good solar cell can have an efficiency of around solar string.
(8) Hydro-electric power plant
(a) 50% (b) 10% (c) 15% (d) 51% Ans. The plant in which the potential energy of the
(10) The natural gas based power plant in Maharashtra water stored in dam is converted into kinetic
is at energy and this kinetic energy drives the turbine
(a) Koyana (b) Chandrapur to generate electrical energy is called hydro-
(c) Anjanvel (d) Tarapur electric power plant.
(11) It took millions of years for the formation of (9) Energy
fuels. Ans. The capacity or stored ability of a body to do
(a) chemical (b) solid work is called energy.
(c) gaseous (d) fossil Q.2.2. Solve the numerical problems:
*(1) In the diagrams below, silicon solar cells with
(12) The photovoltaic cells convert energy
into electrical energy. dimensions 1 cm2 are connected. Find the
potential difference and electric current?
(a) mechanical (b) solar
(c) chemical (d) sound (i) (i) (ii) (iii) (iv)
(13) is not a component of nuclear power
plant.
(i)
(a) control rods (b) gas turbine
(c) steam turbine (d) condenser (ii) (ii)
Ans. (1) (c) Michael Faraday (2) (b) NH3 (3) (c) three (4) (b)
potential (5) (a) DC (6) (c) daytime (7) (d) 200 MeV (iii)
(8) (a) 1kW, 7000kW (9) (c) 15% (10) (c) Anjanvel
(11) (d) fossil (12) (b) solar (13) (b) gas turbine.
Towards Green Energy 87

∴ Total electric current (I) = Ia + Ib

(i) (ii)
= 30 + 30
(iii)
= 60 mA
(iii) (iv)
∴ Potential difference is 1V and electric
Ans. current of 60 mA can be obtained
(i) A silicon solar cell of dimension 1 cm2 can yield 30 *(2) How much potential difference and electric
mA electric current and the potential difference current we can get from 100 cm2 dimension of
of 0.5 V. In the diagram, four cells are connected silicon solar cell?
in series.
Ans. The electric current is proportional to the area
∴Total potential difference = Sum of the but the potential difference is independent of the
individual potential difference area.
∴ V = V1 + V2 + V3 + V4 Area of 1 cm2 can yield 30 mA current
∴ V = 0.5 + 0.5 + 0.5 + 0.5 ∴ The current obtained from 100 cm2 area
∴ V = 2V = 100 × 30
There is no change in the electric current as cells = 3000 mA = 3 A
are in series
The potential difference will remain 0.5 V.
∴ I = 30 mA
Potential difference is 0.5 V and electric current of
(ii) From the silicon solar cell with dimension 1cm2 ,
3 A is produced.
we get electric current of 30 mA and a potential
difference of 0.5 V *(3) One solar panel produces a potential difference
of 18 V and current of 3 A. Describe how you
Since the cells are connected in parallel, there is
can obtain a potential difference of 72 volts and
no change in potential difference.
current of 9 A with a solar array using solar panels.
∴ V = 0.5 V
You can use sign of a battery for a solar panel.
Total current = Sum of individual currents. Ans.
I = I1 + I2 + I3 + − + − + − + −
∴ I = 30 + 30 + 30
∴ I = 90 mA
∴ The potential difference is 0.5 V and current of + − + − + − + −
90 mA is produced.
(iii) 30 mA electric current and 0.5 V potential
difference can be obtained from 1 cm2 silicon
solar cell.
+ − + − + − + −
Since cells (i), (ii) are in series,
Potential difference = Sum of the individual Q.2.3. Answer the following questions:
Potential differences. *(1) What are the different forms of energy?
Va = V1 + V2 (Can you recall Text book pg no. 47)
∴ = 0.5 + 0.5 Ans. Following are the forms of energy : (i) Mechanical
∴ Va = 1V energy (ii) Heat energy (iii) Light energy
Electric current will be the same Ia = 30 mA (iv) Sound energy (v) Electrical energy
(vi) Magnetic energy (vii) Chemical energy (viii)
Since iii and iv are in series,
Nuclear energy
Vb = V3 + V4
*(2) How is Electric energy produced?
= 0.5 + 0.5
(Can you tell Text book pg no. 47)
∴ Vb = 1 V
Ans.
Since (i) and (ii), (iii) and (iv) are in parallel,
(i) Most of the electric power plants are based on the
∴ Potential difference will remain the same. principle of electro - magnetic induction invented
V = Va = Vb = 1 V by Michael Faraday.
88 Master Key Science and Technology - 2 (Std. X)

(ii) According to this, whenever magnetic field

200 Mev
around a conductor changes a potential difference Nuclear Fission

is generated across the conductor and electrical 141Ba

energy is produced. 56

Neutron absorption
*(3) Why the energy in the coal is called as chemical n 200 Mev
energy? n n
235 236
(Lets Think Text book pg no. 49) 92
U 92
U n
92
Ans. 36
Kr
200 Mev
(i) Coal contains carbon and hydrocarbons which 200 Mev

produce heat on combustion.

(ii) Hence energy in coal is called chemical energy. Fig. 5.1 : Nuclear fission (chain reaction)
*(4) How does nuclear fission take place? (5) What are the problems associated with
(Can you tell Text book pg no. 50) hydroelectric power plant?
Ans. Ans.
(i) When a slow moving neutron is bombarded on (i) The back water due to storage of water in dam
Uranium - 235 nucleus, it absorbs the neutron and may submerge villages or towns in that area as
gets converted into its isotope Uranium - 236. well as forests and fertile lands.
(ii) Uranium - 236 being extremely unstable, converts (ii) This leads to the problems of rehabilitation of the
into atoms of Barium and Krypton through a displaced population.
process of fission releasing three neutrons and (iii) The obstruction of the flow of river water may
200 MeV energy. have adverse effects on the aquatic world in the
river.
Q. 2.4 Complete the following flowchart:
(1) Stages in the generation of Electrical Energy from thermal energy.

Boiler for
Electrical
Fuel coal conversion of Steam turbine Generator
energy
water to steam

System for converting

steam back to water

*(2) Step by step Energy Conversion in thermal power plant.

Ans. Chemical energy Thermal Kinetic energy in Kinetic energy in Electrical

in coal energy steam turbine energy

(3) Stages in generation of Electrical energy from nuclear energy.

Ans. System
Nuclear reactor
for steam Electrical
for nuclear Steam turbine Generator
generation from energy
fission
water

Fuel : Uranium System for conversion of

or Plutonium steam back into water.
Towards Green Energy 89

*(4) Step by step Energy conversion in nuclear power plant.

Ans.
Thermal Kinetic energy in Kinetic energy in Electrical
Nuclear energy
energy steam turbine energy

(5) Stages in generation of electrical energy from natural gas.

Ans. Compressor for Combustion Electrical

Gas turbine Generator
pressurised air chamber energy

Natural gas

(6) Step by step energy conversion in power plant of natural gas.

Ans.
Chemical energy in Kinetic energy generated due to Kinetic energy in Electrical
natural gas combustion of natural gas turbine energy

(7) Stages of generation of Electrical energy from hydroelectric power station.

Water stored in
Water
reservoir with Generator Electrical Energy
potential energy Turbine

*(8) Step by step energy conversion in hydroelectric power plant.

Ans.
Potential energy in Kinetic energy in Kinetic energy in Electrical
stored water flowing water turbine energy

(9) Stages in generation of Electrical energy from wind energy.

Ans.
Wind with required Wind Turbine
Generator Electrical energy
velocity with large fins
(10) Step by step energy conversion using wind energy.
Ans.
Kinetic Energy in Kinetic energy in
Electric energy
wind turbine

(11) Conversion of energy generated by solar cells to AC formed using inverter.

Ans.
Electric equipment
Solar cell Battery Inverter
working on AC power
(12) Different stages of generation of electrical energy is solar thermal power plant. OR
Step by Step energy conversion in solar thermal power plant.
Ans.
Absorber for
Concentrators
absorbing the Electric Electrical
for collecting Steam turbine
concentrated generator energy
sunlight
sunlight
90 Master Key Science and Technology - 2 (Std. X)

Q.2.5 Distinguish between:

(1) Bio-fuels and Fossil fuels

Bio-fuels Fossil fuels

(1) The fuels obtained from the decomposition of (1) Fuels obtained from the burials of plants and animal
excretory products of animal and plants are called from the Earth’s crust are called fossil fuels.
bio-fuels.
(2) These fuels are eco-friendly and cause (2) These fuels are not eco-friendly as their combustion
comparatively less pollution. causes pollution.
(3) These fuels are inexhaustible. (3) These fuels are exhaustible.

(4) Examples: (4) Examples:

Gobar gas, ethanol, bio-disel, etc. Coal, natural gas, crude oil, etc.

* (2) Conventional energy sources and Non-conventional energy sources.

Conventional energy sources Non-conventional energy sources.

(1) Conventional energy sources are exhaustible. (1) Non-conventional sources of energy are inexhaustible

(2) Conventional sources of energy cause pollution. (2) Non - conventional sources of energy are pollution
free.
(3) Conventional sources are used extensively by us. (3) Non-conventional sources of energy are not used as
extensively as conventional sources.
(4) These sources require thousands of years to form. (4) They are abundantly available in nature.

(5) Examples: (5) Examples:

Coal, Crude oil, Natural gas, etc. Solar energy, wind energy, bio-gas etc.

*(3) Thermal electricity generation and Solar thermal electricity generation

Thermal electricity generation Solar thermal electricity generation

(1) In thermal power plant coal, natural gas, etc are (1) In solar power plant, solar radiations are used as
used as sources (fuels). the source.
(2) Working of thermal power plant can cause air (2) Solar power plant does not causes air pollution.
pollution.
(3) The rate of electric power generation is very high. (3) The rate of electric power generation is very low.
(4) This energy source is not eco-friendly. (4) This energy source is absolutely eco-friendly.

(4) Solar Cells and Solar thermal plant

Solar Cells Solar thermal plant

(1) Solar or photovoltaic cells convert solar energy into (1) Solar thermal plant converts solar energy into
electrical energy directly. heat energy then into kinetic energy and then into
electrical energy.
(2) Solar photovoltaic cells make use of a semiconductor (2) It uses reflectors to concentrate sunlight on
like silicon. absorbers.
(3) Its design is simple and easy to use. (3) Its design is complex like a thermal power plant.
Towards Green Energy 91

Q.2.6 Give scientific reasons: *(4) Hydroelectric energy, Solar energy and Wind
(1) Atomic energy is an extensive source of energy. energy are called renewable energies.
Ans. Ans.
(i) Atomic energy involves two reactions, viz. (i) Hydroelectric energy, solar energy and wind
Nuclear fission and Nuclear fusion. energy are all obtained without burning of a fuel.

(ii) Both these reactions result in the release of (ii) They do not cause air pollution and are thus,
eco-friendly.
tremendous amount of energy.
(iii) Sunrise, rainfall, wind are natural phenomena.
(iii) Nuclear fission reaction is used in Nuclear power
(iv) These phenomena are constantly and continuously
plants to produce electrical energy.
happening on earth.
(iv) Nuclear fusion reaction takes place in the sun
(v) By setting up hydroelectric power plant, solar
giving us solar energy.
panel and wind mills we can obtain these
(v) Therefore, atomic energy is an extensive source energies continuously, uninterrupted and at low
of energy. cost. Hence, these sources are called renewable
*(2) The construction of turbine is different for energy sources.
different types of power plants. *(5) It is possible to produce energy from mW to
Ans. MW using solar photovoltaic cells OR
(i) Every power plant uses a different kind of source How can we get the required amount of energy
to rotate the turbine. by connecting solar photovoltaic cells?
Ans.
(ii) In thermal and nuclear power plants, steam
produced rotates the turbine. (i) A silicon solar cell of dimension 1 cm2 generates a
current of about 30 mA and potential difference of
(iii) In hydroelectric power plant, flowing water is about 0.5 V. Thus a silicon solar cell of dimension
used to rotate turbines and wind is the medium 100 cm2 will generate about 3 A (30 mA / cm2 ×
in windmills. 100 cm2 = 3000 mA) current and 0.5 V.
(iv) Also the power output of every power plant is (ii) If solar cells are connected in series the potential
different. difference gets added but current remains the
(v) Hence, there should be turbines of different same. If solar cells are connected in parallel the
designs for different power plants. potential difference remains the same but the
current generated is the summation of current
*(3) It is absolutely necessary to control the fission
from individual cells.
reaction in nuclear power plants.
(iii) By using this principle we can obtain power of
Ans. desired quantity.
(i) Nuclear power plants work on the principle of (iv) We can decide the number of solar panels to be
controlled chain reaction. used and what type of combination we can have
(ii) When slow moving neutrons strike the uranium to get required amount of electric power.
nucleus, it splits into Barium and Krypton with (v) Hence, solar photovoltaic cells can be used to
release of three neutrons and tremendous amount obtain mW to MW power.
of energy (200 MeV). (6) In all types of thermal power plants, steam is
used to rotate turbines.
(iii) Three neutrons strike on three more uranium
Ans.
nucleus and fission continues creating tremendous
energy which is harmful. (i) In order to obtain electricity from a power plant, it
is necessary to rotate the turbines.
(iv) Reaction is controlled by using neutron absorbent
(ii) Water is easily available and when water is
material like boron steel and cadmium rods which
heated steam can be formed. When pressure is
absorb excess neutrons and heat generated can be
applied on steam and allowed to pass through a
used for welfare of mankind. small opening we can easily obtain kinetic energy.
(v) Hence, it is absolutely necessary to control the (iii) Kinetic energy of the steam helps to rotate
fission reaction in nuclear power plants. turbines easily and can be reused
92 Master Key Science and Technology - 2 (Std. X)

(iv) Hence, in all types of thermal power plants steam (2) Energy obtained from fossil fuels is not green
is used to rotate turbines. energy.
(7) Boilers of the thermal power plants have tall Ans.
chimneys. (i) Fossil fuels cause pollution during combustion.
Ans. (ii) Burning of coal results in emission of gases like
(i) The thermal power plants mainly use coal and carbon dioxide which is harmful to health.
natural gas as a fuel which have chemical energy. (iii) Coal and oil release sulphur dioxide and soot,
(ii) The combustion of coal or natural gas result in which causes problems related to respiration and
the formation of various gases like carbon dioxide acid rain.
and sulphur dioxide, nitrogen oxide gas which (iv) As fossil fuels harm the environment they cannot
are very dangerous and cause air pollution. be considered as green energy.
(iii) These gases and the produced soot can be Q.3.2.Explain with diagram step-by-step energy
hazardous if released at the normal height. conversion in.
(iv) Tall chimney release them at a height in such a *(1) Thermal power plant:
way that they disperse easily and do not sediment Ans. Refer Q.2.4 (2) for flow chart
(v) Therefore, the chimneys of boilers are much taller. (i) Coal has stored chemical energy and it is used as
a fuel.
(8) Though nuclear energy is an extensive source
(ii) Coal is burnt to obtain heat energy. This is used to
but the amount of electric power generation
boil water to obtain steam.
from nuclear power plants is much less.
(iii) Steam of very high temperature and pressure is
Ans.
generated.
(i) The technology of nuclear power plant is highly
(iv) The kinetic energy of the steam drives the turbines
expensive. thus the generator connected to the turbines
(ii) Similarly, the fuel Uranium required to run these rotates and electricity is generated.
plants is not available in all countries. *(2) The Nuclear power plant
(iii) The fission products sometimes are radioactive Ans. Refer Q.2.4 (4) for flow chart
and can cause environmental pollution.
(i) When fuel U-235 is bombarded with a neutron it
(iv) Disposal of radioactive wastes from the nuclear becomes unstable and splits into Barium, Krypton
power plant is much more difficult as it can cause and 3 neutrons with a lot of energy (200 MeV)
health hazards. (ii) By using this energy, water is boiled to form
(v) Therefore, these plants are used on a limited scale steam.
thus energy production is also less. (iii) By using kinetic energy of steam the turbine is
Q. 3. 1. Explain the following statements: rotated.
*(1) ‘Save energy’ is the need of the hour. (iv) Then the kinetic energy of the turbine is used to
Ans. rotate the generator and electricity is produced.

(i) Energy is necessary to perform work. (3) Hydro-electric power plant

(ii) Day by day the use of energy for various purposes Ans. Refer Q.2.4 (8) for flow chart
is rising. (i) Water stored in a dam’s reservoir has potential
(iii) If we do not harness new sources of energy, the energy.
reserves of fossil fuels would get exhausted faster. (ii) When this water flows, the potential energy gets
(iv) It is estimated that the current reserves would get converted into Kinetic energy.
over in nearly 200 years. (iii) With the help of this Kinetic energy, the turbines
are rotated.
(v) If we save energy today, we may use it for longer
period of time. (iv) The turbine in turn drives the generator to
generate electricity.
(vi) Thus it is important to take every possible measure
to save energy. (4) Solar thermal power plant:
Refer Q.2.4 (12)
Towards Green Energy 93

Ans. (b) ................. energy is a renewable source of energy.

(i) Solar energy is initially converted into heat by (c) Solar energy can be called ................. energy.
concentrating it.
(d) ................. energy of wind is used in wind mills.
(ii) The absorbed sunlight is utilized to boil water
(e) ................. energy of water in dams is used for
and steam is obtained.
generation of electricity.
(iii) Kinetic energy of steam is used to drive turbines.
(iv) The kinetic energy of turbine is used to drive Ans. (a) Thermal (b) Wind (c) Green (d) Kinetic
generators which produce electricity. (e) Potential
a b
Q. 3.3 Solve the following crossword puzzle:
*(1) a b T W
d H I
d K c G R E E N
c
I R D
N M
E A
e
e P O T E N T I A L
I

(a) Maximum energy generation in India is done C

using ................. energy.

Q.3.4. Answer following questions based on figures.

*(1) Compare: Observe the schematic of thermal power plant and the nuclear power plant. Discuss what are
the similarities and differences between the two?

Stack
vapour and hot air
Combustion gases to stack

Generator

Cooling tower
Fuel Condenser
Air Warm water
Pump

Pump
Boiler
Cooled water
Turbine
Fig. 5.2 Thermal Power Plant
Ans. Similarity: In both the power plants water is Differences : In the thermal power plant coal is a
boiled to form steam and kinetic energy of the main fuel that is burnt.
steam rotates the turbine. In the nuclear power plant Uranium - 235 is the
fuel which undergoes nuclear fission.
94 Master Key Science and Technology - 2 (Std. X)

Boiler

Turbine

Generator
Control Rods Pump
Nuclear reactor

Pump Warm water

Cooling tower
Condenser

Fig 5.3 : Nuclear Power Plant

(2) Use your brain Power Text book Pg. No. 54) (3)

Shaft
Wall Power house
A Generator

Sluice gates Gear box Generator

B
Reservoir Air
C Penstock
Turbine

Fig 5.4. hydroelectric plant Blades Bearing Shaft

(a) With reference to point B, potential energy of Support

how much water reservoir in the dam will be Fig 5.5 : wind mill
converted into kinetic energy?
(a) What is the process shown in the diagram?
Ans. The potential energy of water stored in the region
Ans. The process is the conversion of wind energy into
A to B, will be converted into kinetic energy.
electrical energy using a wind mill.
(b) What will be the effect on electricity generation;
if the channel taking water to turbines starts at (b) Give the conversion of energy of the process.

point A? Ans.
Ans. The energy generation will increase as the water Kinetic Energy Kinetic energy Electrical
at A It will have higher potential energy that can in wind in turbine energy

generate higher kinetic energy as it flows.

(c) Is this process environment friendly? Explain.
(c) What will be the effect on electricity generation,
Ans. Yes, this process is environmentally friendly as
if the channel taking water to turbine starts at
it does not involve the burning of fuels which
point C.
produce harmful gases as by products.
Ans. The energy generation will decrease as the water
at C will have lower potential energy that will (d) What are the disadvantages of this process?

generate lower kinetic energy as it flows. Ans. The disadvantage of this process is that the
minimum wind velovity necessary for wind
energy generation is not available every where.
Towards Green Energy 95

(4)
(a) Label A, B and C in the diagram
Emission of
hot gases Ans. A : Module, B : String, C : Array
Combustion (b) What is considered as a basic unit of a solar
Fuel chamber electric plant?
Generator Ans. A Solar cell is the basic unit of a solar electric
plant.
Gas
Compressor (c) What are the modules connected in series
turbine
called?
Electrical energy Ans. The modules connected in series are called as
string.
(d) What is the type of current obtained from a solar
Fig. 5.6
cell?
(a) Which energy is produced? Ans. DC current.
Ans. Electrical energy.
(6) Energy from light
(b) What is this power plant based on?
Ans. Generation of electricity from natural gas Power grid
(c) Is this energy generation eco-friendly? Why? Inverter and
Ans. Transformer
(i) No, this energy generation is not eco-friendly
as it leads to emission of certain gases and soot
particles which leads to air pollution.
(ii) Also it takes millions of years for formation of Solar Array
natural gases and their reserves are limited.
(5) C
A B Fig. 5.8
(a) What is the diagram about?
Ans. It is a schematic diagram of a solar photovoltaic
station.
(b) What is the device used to convert DC solar
power to AC solar power called?
Ans. An Inverter is used to convert DC solar power to
AC solar power.
(c) What is the use of transformer?
Fig. 5.7 Ans. A transformer transforms the voltage and current
levels of generated power which is then fed into
electricity distribution network.

(7) Power grid

Solar energy Solar energy
Steam

Flow of hot water

Absorber
Generator
B

Steam Water
A C

Fig. 5.9
96 Master Key Science and Technology - 2 (Std. X)

(a) Name the power plant shown in the diagram

Ans. Solar Thermal Power Plant.
(b) Label A, B and C in the diagram.
Ans. A - Solar Panel, B - Condenser, C - Cooling Tower.
(c) Complete the flow chart for stages of energy generation in the above power plant.

Electrical
Concentrators
energy
Ans.

Electric Electrical
Concentrators Absorbers Steam turbine
generator energy

(8)

Fig. 5.10
(a) Label A and B in the diagram Q.3.5. Draw neat and labelled diagrams for the
Ans. A - Condenser, following
(1) Electromagnetic Induction
B - Control rods.
Ans.
(b) Define nuclear fission.
Lines of flux
Ans. The splitting of heavy nucleus of Uranium into Coil
Barium, Krypton and three neutron, with release Voltmeter
of energy is called nuclear fission.
(c) State the drawbacks of a nuclear power plant. Induced
Ans. emf

(i) Products of nuclear fission called nuclear waste

are all radioactive. The disposal of nuclear waste
is a big challenge. Rotating
magnetic field
(ii) Sometimes accident can occur which can leak
harmful radiations.
Fig. 5.11. Electromagnetic Induction
(iii) Radiation pollution can be most dangerous.
Towards Green Energy 97

(2) Schematic of electric generator (5) A solar panel made from 36 solar cells.
Ans. Ans.
Generated
electrical energy

−
+

Rotating
Electric
Fig 5.15. Solar panel made from 36 solar cells
magnet Q.4. Answer the following questions in brief:
*(1) Which fuel is used in thermal power plant?
What are the problems associated with this type
Fig. 5.12. Electric generator of power generation?
(3) Series combination of solar cell. Ans. In the thermal power plant coal is used as a fuel.
Problems created by thermal power plant:
Ans.
(i) The combustion of coal results in emission of gases
Cell 1 Cell 2 like CO2, NO2, SO2, which causes air pollution.
(ii) During combustion of coal, soot is formed thus
carbon particles added to air can cause respiratory
− +
− problems.
I = I 1 = I2 (iii) Large amount of coal is required for this plant
which may deplete the coal reserves rapidly. In
the shortage or lack of coal the thermal power
V1 V2
plant could be shut down.
VTotal = V1 + V2 *(2) Which types of power generation involve
maximum number of steps of energy conversion?
Fig 5.13. Solar cells in series In which type of power generation is the number
minimum?
(4) Solar cells in parallel
Ans.
Ans.
(i) The nuclear power plant has maximum steps for
the generation of electricity.
Cell 1 I1 Kinetic Kinetic
Nuclear Thermal Electrical
energy energy in
energy energy energy
− + in steam turbine

(ii) The flow chart of nuclear power plant

I = I1 + I 2
I2 Nuclear System
Cell 2 reactor for steam Steam Electrical
for turbine Generator
generation energy
− + nuclear from
fission water
V = V1 = V2

Fig 5.14. Solar cells is parallel Fuel: System for

Uranium / conversion of steam
Plutonium back into water
98 Master Key Science and Technology - 2 (Std. X)

(iii) The transformation of energy in an electric (iv) Thus, energy obtained from these sources are
generator using wind energy has miniumum called as green energy.
number of steps: (5) How does the nuclear fission process takes place
in the nuclear power plant?
Kinetic energy Kinetic energy Electric Ans. (For diagram refer Fig. 5.1)
in wind in turbine energy (i) The nuclear power plant works on the principle of
(vi) Stages in electric energy generation using wind converting nuclear energy to electrical energy.
energy. (ii) The Uranium nucleus U-235 is bombarded with
a slow moving neutron. The uranium nucleus
Wind with Wind turbine absorbs it and is converted into its isotope U-236
Electrical
required with large Generator which is extremely unstable splits into Barium
energy
velocity fins
and Krypton with release of three neutrons and
tremendous amount of energy.
*(3) Other than thermal power plant, which power
(iv) The released neutrons carry out fission of three
plants use thermal energy for power generation?
more uranium nuclei and the process continues.
In what different ways is the thermal energy
This sets the chain reaction which is uncontrolled
obtained?
and may result in an explosion. But it is controlled
Ans. in the process by using neutron absorbing
(i) Thermal energy is used in power plants using material.
coal, Uranium, Natural gas, (LPG and CNG) as (v) Boron steel and cadmium rods are used to absorb
fuels. neutrons
(ii) Generally, thermal power plant uses coal to (vi) Thus the reaction gets controlled and the energy
produce heat and chemical energy of coal is released can be used for generating electricity.
converted into heat during the combustion. (vii) Hence the basis of nuclear power plant is
controlled chain reaction.
(iii) Apart from coal, natural gas, LPG and CNG are
also used as fuel for the thermal power plant. *(6) How can you obtain the required amount of
energy by connecting solar panels?
(iv) Nuclear power plant uses uranium as the source
Ans.
of energy.
(i) Solar cells contain the semiconductor Silicon
(v) In the nuclear power plant the nuclear fission of
(ii) A Silicon solar cells of area 1 cm2, can generate 30
uranium results in the production of heat which
mA of electricity and 0.5V potential difference is
is utilized for the production of steam.
obtained.
(vi) In the solar thermal plant, the heat is obtained by (iii) If two solar cells are connected in series the
concentrating solar radiations and then steam is potential difference get added to 1V but electric
produced. current remains the same.
(4) What is green energy? Which energy sources can (iv) It two solar cells are connected in parallel, the
be called as green energy source and why? Give current becomes 60 mA but potential difference
examples. remains the same. In this manner we can get the
Ans. required potential difference and electric current.
(i) The eco-friendly energy is called green energy. *(7) What are the advantages and limitations of solar
energy?
(ii) The energy production which does not cause any
damage to environment is actually a green energy. Ans. Advantages of solar energy:
(i) Solar energy is a clean source of energy.
(iii) Solar energy, wind energy, hydro electric energy
do not harm the environment as there is no (ii) It is a sure source of energy.
combustion involved and there is no air pollution (iii) It is eco-friendly source of energy.
caused. (iv) Since there is no combustion of fuel there is no
pollution of air.
Towards Green Energy 99

(v) This energy source is in-exhaustible. (vi) Compared to thermal and nuclear power plants
(vi) Solar energy can be easily converted into the hydroelectric power plant, is definitely eco-
electricity for use. friendly.
Limitations of using solar energy:- (vii) Rehabilitation of people is necessary for people
(i) Solar radiations are available only in day time. whose land is used for construction of dam.
(ii) Storage equipment are costly and initial (10) Write the advantages and limitation of wind
installation cost is very high. power?
(iii) Radiation intensity is not constant throughout the Ans. Advantages of wind power.
day, hence it is not an even or uniform source. (i) Wind possess kinetic energy which rotates
(iv) Solar panels occupy lot of space, hence there is an turbines and electricity is generated.
issue of space for installation. (ii) In the entire process there is no combustion of any
(v) It is not concentrated source as solar energy is fuel, hence no air pollution.
scattered. (iii) Thus wind energy is really a clean and eco-
(vi) Sunlight of power 100 W/cm2 can produce only friendly source of energy.
15W power. i.e. the efficiency of equipments is (iv) Since no fuel is required, there is no fear of getting
15% which is low. raw material exhausted.
(8) Write the advantages and limitation of Nuclear (v) The area under the wind mill can be used for
energy: agriculture.
Ans. Advantages of Nuclear energy:
Limitations of wind power :
(i) Use of nuclear energy does not emit gases which
(i) Slower wind produces 9 kW power while if there
lead to air pollution.
is lot of wind then around 7 MW power can be
(ii) Storage of fuel and transport issues do not arise. generated. If there is not enough speed of wind,
(iii) Nuclear energy is an extensive and good source generation of power will be less.
of energy . *(11) Write short notes on: Electrical energy generation
Limitation of nuclear energy. and environment
(i) Products of nuclear fission called nuclear waste Ans.
are all radioactive. The disposal of nuclear waste (i) The environment impact of electricity generation
is a big challenge. is significant because modern society needs large
(ii) Sometimes accident can occur which can leak amount of electrical power.
harmful radiations. (ii) The power is normally generated at power plants
(iii) Radiation pollution can be most dangerous. that converts some other kind of energy into
*(9) Give your opinion about whether hydroelectric electrical power.
plants are environment friendly or not? (iii) Each system has some advantages and
Ans. disadvantages, but many of them pose
(i) In the hydroelectric power plant, kinetic energy of environmental concerns.
water get converted into electricity. (iv) Thermal power plants give out CO2, NO2, SO2
(ii) The water stored in the dam possess potential which causes air pollution.
energy. As this water is allowed to flow, this (v) Nuclear power plant pose the threat of disposal of
energy gets converted into kinetic energy. nuclear waste and radiation leakage.
(iii) The kinetic energy of water is used to rotate the (vi) Wind mills and solar power plants are
turbines and electricity is generated. eco-friendly but installation cost is high hence is
(iv) In this, since no fuel is burnt, there is no air used less frequently.
pollution and thus it is eco-friendly (vii) Hydroelectric power plants are Eco-friendly and
(v) Water mass does not get polluted as there are no generate sufficient electricity but rehabilitation
effluents. This water can be used for agricultural of people is necessary, whose land is used for
purposes. construction of dam.

vvv
100 Master Key Science and Technology - 2 (Std. X)

ASSIGNMENT - 5
Time : 1 Hr. Marks : 20

Q.1. Answer the following: (3)

(1) Fill in the blank: A transformer transforms the .................. and current levels of the generated
power.
(2) Name the following: The principle invented by Michael Faraday.
(3) State whether True or False: Water is boiled using boiler.
Q.1. (B) Choose and write the correct option: (2)
(1) Each nuclear fission of uranium nucleus releases .................. energy.
(a) 20 MeV (b) 236MeV (c) 237 MeV (d) 200 MeV
(2) Water stored in dams possess .................. energy.
(a) chemical (b) potential (c) kinetic (d) electric
Q.2. Answer the following (Any 2) (4)
(1) Distinguish between: Biofuels and Fossil fuels.
(2) Give Scientific reason: Energy obtained from fossil fuels is not green energy.
(3) How much potential difference and electric current can we get from 100 cm2 dimension of silicon
solar cells?
Q.3. Answer the following (Any 2) (6)
Energy from
light (1) Observe the figure carefully, and explain how power is
generated in a solar photovoltaic station.
Power grid
(2) Explain the working of solar thermal power plant, with
Inverter and
the help of a flow chart.
Transformer
(3) One solar panel produces a potential difference of 18V
and current 3A. Describe how you can obtain a potential
difference of 72 volts. You can use size of a battery for a
Solar Array solar panel.

Q.4. Answer the following (Any 1) (5)

(a) What is a wind turbine?

(b) What is the functional use of gear box?
(c) What are various stages in electricity generation using
wind energy?

(2) Explain in detail the advantages of hydroelectric power generation and problems associated with
hydroelectric power plant.
vvv
 6 Animal Classification
CONCEPT MAP

(1) Criteria of new system of Animal classification:

Kingdom Body organization Body symmetry Body cavity Phylum

Kingdom: Cellular Asymmetrical Acoelomate (1) Porifera

Animalia grade body
(Multicellular
organisms Tissue/ organ/ Radial Acoelomate (2) Cnidaria
without cell organ-system symmetry
wall) grade
Acoelomate (3) Platyhelminthes
Bilateral
symmetry
Pseudocoelomate (4) Aschelminthes

Eucoelomate (5) Annelida

(6) Arthropoda
Ki
ng
do
m (7) Mollusca
-A
nim
ali
a (8) Echinodermata

(9) Hemichordata

(10) Chordata

(2) Conventional system of Animal Classification:

Kingdom Animalia

Sub-kingdom Sub-Kingdom
Non-chordates Chordates

Phylum Chordata
Hemichordata
Echinodermtaata
Platyhelminthes
Phylum :
Phylum :

Cnidaria

Aschelminthes
Phylum :

Porifera
Protozoa

Arthropoda

Mollusca
Phylum :
Annelida
Phylum :

Phylum :
Phylum :
Phylum :
Phylum :

Phylum :

Urochordata Cephalo - Vertebrata

chordata

Class Class Class Class Class Class

Cyclostomata Pisces Amphibia Reptilia Aves Mammalia

(101)
102 Master Key Science and Technology Part-2 (Std. X)

Points to Remember:
zz According to recent studies, estimated number of animal species on the earth is approximately seven millions.

zz It is impossible to study each and every species together. However, the systematic grouping, i.e. classification
will make it very easy to study such vast variety of animals.

zz Greek Philosopher Aristotle was the first to perform animal classification. Classification proposed by him is
known as ‘Artificial Method’.

zz Besides Aristotle, this method was followed by Theophrastus, Pliny, John Ray, Carl Linnaeus, etc.

zz Later on, ‘Natural System of Classification’ was followed. It was based on the various criteria like body
organization, types of cells, chromosomes, bio-chemical properties, etc.

zz By the time, system of classification based on evolution was also brought into practice. It was used by
Dobzhansky and Meyer.

zz Recently Carl Woese has also proposed the animal classification.

zz Traditionally, depending upon presence or absence of the notochord, the animal kingdom has been classified
into two groups: Non-chordates and Chordates.

zz ‘Non-Chordates are further classified into 10 phyla. Protozoa, Porifera, Cnidaria, Platyhelminthes,
Aschelminthes, Annelida, Arthropoda, Mollusca, Echinodermata, Hemichordata.

zz Chordates are further classified into Urochordata, Cephalochordata and Vertebrata.

zz Sub-phylum Vertebrata is divided into six classes Cyclostomata, Pisces, Amphibia, Reptilia, Aves and
Mammalia.

zz According to Robert Whittaker, all multicellular animals are included in Kingdom Animalia.

zz There are different criteria for classifying animals. They are Grades of Organization, Body symmetry, Germ
layers, Body cavity (Coelom), Body segmentation.

(7) All higher animals show

MASTER KEY QUESTION SET - 6
organization.
Q.1. (A) 1. Fill in the blanks and rewrite the statement: (8) The cavity between the body and internal organs
(1) Greek philosopher classified animals is called .
for the first time. (9) If the body cavity is absent, the animal is called
(2) The long rod like supporting structure present .
on the dorsal side of animal body is called (10) Body cavity is absent in .
. (11) In Aschelminthes, the body cavity is not formed
(3) According to Robert Whittaker, all multicellular by mesoderm. So, they are called as .
animals are included in kingdom . (12) If the body of animals is divided into small, similar
(4) Body organization of unicelluar animals is units, then such a body is called as .
referred to as organization. (13) Animals belonging to Porifera have special types
(5) In case of multicellular animals, the body of cells called .
organization is referred to as (14) The animals belong to Porifera bear numerous
(6) Flat worms show organization. pores on their body called .
Animal Classification 103

(15) Body of animals from is cylindrical (6) Scorpion, Earthworm, Nereis, Leech.
or umbrella-like. Ans. Scorpion - Others belong to Annelida whereas
(16) If the body of a coelenterata is cylindrical, it is Scorpion belongs to Arthropoda.
called . (7) Spider, Cockroach, Butterfly, Bivalve.
(17) Spicules are made up of . Ans. Bivalve - Others belong to Phylum Arthropoda
(18) The precious stone is derived from whereas bivalve belongs to Mollusca.
coral reefs. (8) Bat, Whale, Monkey, Ostrich.
(19) Annelides have for locomotion. Ans. Ostrich - Others are Mammals whereas ostrich
(20) In arthropods, exoskeleton is present belongs to class aves.
around the body. (9) Platyhelminthes, Cnidaria, Arthropoda, Annelida
(21) Hemichordates are also called . Ans. Cnidaria - Others are triploblastic whereas
(22) Through the point of view of evolution, cnidaria are diploblastic.
is considered as connecting link (10) Sycon, Euspongia, Adamsia, Euplectella.
between non-chordates and chordates. Ans. Adamsia - Others belong to Phylum Porifera
(23) The flying mammal is . whereas Adamsia belongs to Coelenterata.
(24) Reptilians are blooded animals. (11) Sea anemone, Hydra, Aurelia, Ascaris.
(25) Aves are blooded animals. Ans. Ascaris - Others are coelenterates whereas Ascaris
Ans. (1) Aristotle (2) Notochord (3) Animalia belongs to phylum Aschelminthes.
(4) protoplasmic grade (5) cellular grade organization (12) Parrot, Bat, Pigeon, Crow.
(6) tissue organ grade, (7) organ system grade Ans. Bat - Others belong to class Aves whereas bat
(8) Coelom (9) acoelomate (10) Porifera (11) belongs to class mammals.
Pseudocoelomates (12) segmented body (13) collar (13) Bivalve, Butterfly, Octopus, Snail.
cells (14) ostia (15) Cnidaria (16) Polyp (17) calcium Ans. Butterfly - Others belong to Mollusca whereas
carbonate (18) Coral (19) setae, (20) chitinous (21) butterfly belongs to Arthropoda.
acorn worms (22) Balanoglossus (23) bat (24) cold
(14) Lizard, Snake, Penguin, Python.
(25) warm
Ans. Penguin - Others belong to Reptilia whereas
Q.1. (A) 2. Find the odd one out. Penguin belongs to mammals.
(1) Annelida, Arthropoda, Reptilia, Mollusca. (15) Dog fish, Shark, Rohu, Salamander.
Ans. Reptilia - Others are non-chordates whereas Ans. Salamander - Others belong to class pisces
reptitia are chrodates. whereas Salamander belongs to class Amphibia.
(2) Protozoa, Cyclostomata, Amphibia, Aves. (16) Sea horse, Frog, Toad, Salamander.
Ans. Protozoa - Others are classes of Chordates Ans. Sea horse - Others are amphibians whereas Sea
whereas Protozoa is Non chordate. horse belongs to class pisces.
(3) Hydra, Sea anemone, Sycon, Coral. (17) Kangaroo, Kiwi, Penguin, Peacock.
Ans. Sycon - Others are Coelenterates whereas Sycon Ans. Kangaroo - Other are Aves whereas Kangaroo
belongs to Porifera. belongs to mammals.
(4) Jellyfish, Starfish, Sea-urchin, Planaria. (18) Starfish, Dogfish, Brittle star, Sea urchin.
Ans. Planaria - Others show radial symmetry whereas Ans. Dogfish - Others belong to Echinodermata
Planaria shows bilateral symmetry. whereas Dogfish belongs to class pisces.
(5) Earthworm, Crab, Mosquito, Spider. (19) Pseudopodia, Cilia, Setae, Ostia.
Ans. Earthworm - Others belong to Arthropoda Ans. Ostia - Others are locomotory organs whereas
whereas earthworm belongs to Annelida. ostia are pores on the body of porifera.
104 Master Key Science and Technology Part-2 (Std. X)

Q.1. (A) 3. Complete the analogy. phylum with highly successful animals in animal
(1) Amoeba : Asymmetrical : : Frog : . kingdom whereas Phylum Mollusca is the second
Ans. Bilaterally symmetrical - Body of Amoeba is largest Phylum in animal kingdom.
Asymmetrical whereas that of frog is Bilaterally (13) Salamander : Amphibia :: Balanoglossus : .
symmetrical. Ans. Hemichordata - Salamander belongs to phylum
(2) Fish : Bilateral symmetry : : Starfish : Amphibia whereas Balanoglossus belongs to
Ans. Radial symmetry - Body of fish is Bilaterally phylum Hemichordata.
symmetrical while body of starfish is Radially (14) Pigeon : Aves : : Bat : .
symmetrical. Ans. Mammalia - Pigeon belongs to class Aves whereas
(3) Ostia : to take in water : : Oscula : . Bat belongs to phylum Mammalia.
Ans. To leave water out - Animals in phylum porifera (15) Herdmania : Urochordata :: Amphioxus .
have pores called ‘Ostia’ which is used to take in Ans. Cephalochordata - Herdmania belongs to
water and ‘Oscula’ is used to leave water out. subphylum Urochordata and Amphioxus belongs
(4) Liverfluke : hermaphrodite : : Ascaris : . to subphylum Cephalochordata.
Ans. Unisexual – Liverfluke is hermaphrodite whereas (16) Starfish : Echinodermata :: Balanoglossus :
Ascaris is Unisexual. .
(5) Sea anemone : Diploblastic : : Planaria : . Ans. Hemichordata - Starfish belongs to phylum
Ans. Triploblastic - The body of sea anemone is made Echinodermata whereas Balanoglossus belongs to
of two germ layers hence called Diploblastic phylum Hemichordata.
whereas the body of Planaria is made of three (17) Planaria : Platyheminthes :: Filarial worm : .
germ layers, hence called Triploblastic. Ans. Aschelminthes - Planaria belongs to phylum
(6) Shark : Pisces : : Toad : . Platyhelminthes whereas Filarial worm belongs ot
Ans. Amphibia - Shark belongs to class Pisces whereas phylum Aschelminthes
Toad belongs to class Amphibia. (18) Earthworm : Annelida :: Millipede : .
(7) Aves : Homeotherms : : Reptilia : . Ans. Arthropoda - Earthworm belongs to phylum
Ans. Poikilotherms - Members of class aves are Annelida whereas millipede belongs to phylum
Homeotherms (warm blooded) whereas members Arthropoda.
of class Reptilia are Poikilotherms (cold blooded). Q.1. (A) 4. Match the following :
(8) Scolidon : Cartilagenous : : Pomfret : . (1)
Ans. Bony - The exoskeleton of Scolidon is Column A Column B
Cartilagenous whereas that of Pomfret is bony. (1) Acoelomate (a) Starfish
(9) Amoeba : Pseudopodia : : Earthworm : (2) Radially Symmetrical (b) Frog
Ans. Setae - Amoeba uses Pseudopodia for locomotion
(3) Bilaterally Symmetrical (c) Amoeba
while Earthworm uses Setae for locomotion.
(10) Scorpion : Arthropoda : : Snail : . Ans. (1 – c), (2 – a), (3 – b).
Ans. Mollusca - Scorpion is a member of class (2)
Arthropoda whereas snail is a member of class Column A Column B
Mollusca.
(1) Porifera (a) Sea anemone
(11) Starfish : Tube feet : : Euglena : .
Ans. Flagellum - The locomotory organ of Starfish is (2) Coelenterata (b) Ascaris
tube feet whereas that of Euglena is Flagellum.
(3) Platyhelminthes (c) Sycon
(12) Largest phylum : Arthropoda : : Second largest
phylum : . (4) Aschelminthes (d) Liverfluke

Ans. Mollusca - Phylum Arthropoda is the largest Ans. (1 – c), (2 – a), (3 – d), (4 – b).
Animal Classification 105

(3) (7)
Column A Column B Column A Column B
(1) Annelida (a) Jointed appendages (1) Tube feet (a) Hydra
(2) Ventral foot (b) Nereis
(2) Arthropoda (b) Segmented body
(3) Setae (c) Snail
(3) Mollusca (c) Flat body
(4) Tentacles (d) Earthworm
(4) Echinodermata (d) Soft body
(5) Parapodia (e) Starfish
(e) Spiny body
Ans. (1 – e), (2 – c), (3 – d), (4 – a), (5 – b).
Ans. (1 – b), (2 – a), (3 – d), (4 – e).
(8)
(4)
Column B
Column A (Class)
Column A Column B (Example)
(1) Hemichordata (a) Amphioxus (1) Mammalia (a) Sea horse
(2) Cephalochordata (b) Saccoglossus (2) Pisces (b) Elephant
(3) Urochordata (c) Petromyzon (3) Reptilia (c) Toad
(4) Cyclostomata (d) Herdmania
(4) Amphibia (d) Tortoise
Ans. (1 – b), (2 – a), (3 – b), (4 – c).
Ans. (1 – b), (2 – a), (3 – d), (4 – c).
(5)
(9)
Column A Column B
Column A Column B
(1) Pisces (a) Lungs (1) Arthropoda (a) Head, Foot, Visceral
mass
(2) Amphibia (b) Gills
(2) Hemichordata (b) Head, neck, trunk, tail
(3) Aves (c) Skin
(3) Mollusca (c) Proboscis, collar, trunk
Ans. (1 – b), (2 – c), (3 – a).
(4) Mammalia (d) Head, thorax, abdomen
(6)
Ans. (1 – d), (2 – c), (3 – a), (4 – b).
Column A Column B (10)
(1) Pisces (a) Salamander
Column A Column B
(2) Amphibia (b) Penguin (1) Protoplasmic grade (a) Flat worms
(3) Reptilia (c) Scoliodon (2) Tissue - organ grade (b) Arthropoda
(4) Aves (d) Dolphin (3) Cell - tissue grade (c) Unicellular
animals
(5) Mammalia (e) Tortoise
(4) Organ-system grade (d) Cnidarians
Ans. (1 – c), (2 – a), (3 – e), (4 – b), (5 – d).
Ans. (1 – c), (2 – a), (3 – d), (4 – b).
(11)
Column A Column B Column C
(1) Coelenterata (i) Body covered by shell (a) Balanoglossus
(2) Aschelminthes (ii) Gill slits for respiration (b) Bivalve
(3) Arthropoda (iii) Mostly parasitic, cylindrical (c) Hydra
(4) Mollusca (iv) Jointed appendages (d) Cockroach
(5) Hemichordata (v) Aquatic with radial symmetry (e) Ascaris
Ans. (1 – v – c), (2 – iii – e), (3 – iv – d), (4 – i – b), (5 – ii – a).
106 Master Key Science and Technology Part-2 (Std. X)

Q.1. (A) 5. State whether the following statement is organisation’. (2) True (3) False. The classification
True or False. Correct the false statement. was known as ‘Artificial method of classification’.
(1) Platyhelminthes show ‘organ system grade (4) False. In non-chordates, pharyngeal gill slits are,
organization’. absent. (5) True (6) True (7) False. Animals with
true body cavity are called eucoelomates. (8) True
(2) The first man to classify animals was Aristotle.
(9) True (10) False. In cyclostomata, the endoskeleton
(3) Classification proposed by Aristotle is known as is Cartilagenous (11) True (12) False. Arthropods
‘Natural method of classification’. are unisexual. (13) True (14) False. Spider belongs
(4) In non-chordates, pharyngeal gill-slits are to Arthropoda. (15) True (16) False. Tentacles help
present. in capturing prey. (17) True (18) True (19) False.
(5) The basic unit of all animals is cell. Liverfluke is an endoparasite. (20) False. The body
(6) The human body is bilaterally symmetrical. of arthropods is covered by a chitinous exoskeleton.
(21) False. Earthworm belongs to phylum Annelida.
(7) Animals with true body cavity are called
(22) False. The body of molluscs is soft and slimy.
acoelomates.
(23) False. In amphibia, exoskeleton is absent.
(8) Octopus can change its body colour. (24) False. Amphioxus belongs to Cephalochordata.
(9) The exoskeleton of echinoderms contain calcium (25) False. Reptiles are Poikilotgherms (Cold-blooded).
carbonate. (26) False. Petromyzon belongs to class cyclostomata.
(10) In cyclostomata, the endoskeleton is bony. (27) False. In urochordata, notochord is present in only
tail region. (28) False. Cnidoblast bearing tentacles are
(11) Bat is a flying mammal.
present around the mouth in Coelenterata. (29) True.
(12) Arthropods are hermaphrodites.
Q.1. (A) 6. Name the following:
(13) The mouth of Aves is modified into beak.
(1) One Poriferan
(14) Spider belongs to Annelida.
Ans. Sycon
(15) Euspongia is a sedentary animal.
(2) Animal having tentacles around mouth.
(16) Tentacles of coelenterates help in injecting toxin
in the body of prey. Ans. Hydra

(17) Ascaris is unisexual. (3) Animal whose body is made up of segments.

(18) A precious stone called coral is derived from Ans. Earthworm

coral reef. (4) A connecting link between Non-chordates and
(19) Liverfluke is an ectoparasite. chordates.

(20) The body of arthropods is covered by a tough Ans. Balanoglossus

cuticle. (5) Cartilagenous fish
(21) Earthworm belongs to phylum Aschelminthes. Ans. Shark
(22) The body of molluscs is covered with calcareous (6) Aquatic mammal
spines. Ans. Dolphin
(23) In amphibia, exoskeleton is in the form of scales. (7) Acoelomate, unicellular animal
(24) Amphioxus belongs to urochordata. Ans. Amoeba
(25) Reptiles are homeotherms (warm-blooded). (8) Animal showing three germ layers
(26) Petromyzon belongs to class Pisces. Ans. Triploblastic
(27) In urochordata, notochord is present throughout (9) Locomotory organs in Annelids.
the body length. Ans. Setae, Suckers, Parapodia
(28) Cnidoblast bearing tentacles are present around Q.1. (A) 7. Answer the following in one sentence each:
the mouth in Porifera.
(1) How are animals classified broadly?
(29) Platyhelminthes are hermaphrodites.
Ans. Animals are broadly classified into Chordates
Ans. (1) False. Platyhelminthes show ‘Tissue organ grade and Non-chordates.
Animal Classification 107

(2) Who was the first to classify animals? (15) Which animal is referred to as friend of farmers?
Ans. Aristotle was the first philosopher to classify Ans. Earthworm is referred to as friend of farmers.
animals. (16) What are the parts of the body of Hemichordata?
(3) What was the basis of natural system of Ans. The body of Hemichordates is divided into
classification? proboscis, collar and trunk.
Ans. The natural system of classification was based on (17) What are cold-blooded animals?
various criteria like body organization, types of Ans. The animals whose body temperature changes
cells, chromosomes, bio-chemical properties, etc. with that of the surrounding temperature are
(4) How are chordates further classified? called cold blooded or poikilothermic animals.
Ans. The chordates are further classified as Urochordata, (18) Which is the main respiratory organ for
Cephalochordata and Vertebrata (Craniata). amphibians?
(5) What are Platyhelminthes? Ans. The skin is the main respiratory organ present in
amphibians.
Ans. The animals which are slender, flat like a leaf or
strip are called Platyhelminthes. (19) What do you mean by the term ‘Homeotherm’?

(6) What do you mean by the term ‘triploblastic’? Ans. The animals which can maintain a constant
body temperature irrespective of surrounding
Ans. The animals whose body is made up of three
temperature are called Homeotherms.
germ layers, namely ectoderm, mesoderm and
*(20) Which are the animals from phylum Arthropoda
endoderm are called ‘triploblastic’.
those have shortest and longest life span?
(7) Why are Aschelminthes called round worms?
Ans. Among arthropods, houseflies have very small
Ans. The body of Aschelminthes is long, thread-like or life span, while honey bees have longest life span.
cylindrical, hence, are called as ‘Round Worms’.
Q.1. (A) 8. Identify me:
(8) What is Annelida?
*(1) I am diploblastic and acoelomate. Which phylum
Ans. The animals which are long, cylindrical and do I belong to?
metamerically segmented are called Annelides.
Ans. Coelenterata (cnidaria)
(9) What are the germ layers found in Cnidarians?
(2) I locomote with tube feet, I have radial symmetry.
Ans. Cnidarians have two germ layers, namely
Ans. Starfish
ectoderm and endoderm.
(3) I am a friend of farmers.
(10) What do you mean by the term Arthropoda?
Ans. Earthworm
Ans. The non-chordates which show jointed
(4) I lay eggs though I am a mammalian.
appendages are called Arthropods.
Ans. Platypus
(11) What is the substance present in the exoskeleton
of Arthropods? (5) My digits are without claws and external ear is
absent. Which class do I belong to?
Ans. The substance present is the exoskeleton of
Ans. Amphibia
Arthropods is chitin.
(6) I make pearl in my body.
(12) Name the largest and the second largest phyla.
Ans. Oyster, Bivalve
Ans. ‘Arthropoda’ is the largest phylum, while
‘Mollusca’ is the second largest phylum. (7) I am an annelid ectoparasite that sucks blood.
Ans. Leech
(13) Name the different parts in which body of
Arthropoda is divided. (8) I belong to mammalia, but I can fly.
Ans. The body of Arthropoda is divided into head, Ans. Bat
thorax and abdomen. (9) I am a mammal who lives in deep oceans.
(14) Name the parts in which the body of Molluscan Ans. Whale
is divided. (10) I am a small, fish-like marine animal with
Ans. The body of a Mollusca is divided into head, foot notochord present throughout the body length.
and visceral mass. Ans. Amphioxus
108 Master Key Science and Technology Part-2 (Std. X)

(11) I am an annelid and hermaphrodite. (7) The mammal which lays eggs is .
Ans. Earthworm (a) Platypus (b) Bat
(12) My body is made up of fibres of a protein- (c) Whale (d) Bear
spongin. (8) shows bilateral symmetry.
Ans. Bath sponge (a) Amoeba (b) Starfish
(13) I am a clever molluscan, I can change my colour. (c) Fish (d) Jellyfish
Ans. Octopus (9) In annelida, help in locomotion.
(14) I am considered as the link between Non- (a) pseudopodia (b) cilia
chordates and chordates.
(c) flagella (d) setae
Ans. Balanoglossus
(10) The warm blooded animals are called .
(15) I am the largest animal.
(a) Poikilotherms (a) Homeotherms
Ans. Blue whale
(c) Ambitherms (d) Parasitic
*(16) My body is radially symmetrical. Water vascular
system is present in my body. I am referred as (11) In , the exoskeleton is absent.
fish though I am not. What is my name? (a) Amphibia (b) Aves
Ans. Jelly fish (c) Reptilia (d) Mammalia
*(17) I live in your small intestine. Pseudocoelom is (12) The animals which do not possess body cavity
present in my thread like body. In which phylum are called .
will you include me? (a) Acoelomate (b) Coelomate
Ans. Aschelminthes (c) Pseudocoelomate (d) Eucoelomate
*(18) Though I am multicellular, there are no tissues in (13) The are exclusively marine.
my body. What is the name of my phylum?
(a) Molluscs (b) Coelenterates
Ans. Coelenterata / Cnidaria
(c) Annelids (d) Echinoderms
Q.1. (B) Choose and write the correct option.
(14) In , the fertilization is external.
(1) The first person to perform classification of
(a) Frog (b) Bat
animals was .
(c) Snake (d) Parrot
(a) Theophrastus (b) Linnaeus
(c) Aristotle (d) Meyer *(15) Which special cells are present in the body of
sponges (Porifera)?
(2) Pharyngeal gill-slits are absent in .
(a) Collar cells (b) Cnidoblasts
(a) Non-chordates (b) Chordates
(c) Germ cells (d) Ectodermal cells
(c) Vertebrates (d) Craniates
(3) In multicellular organisms, the body organization *(16) Which of the following animals’ body shows
is called organization. bilateral symmetry?

(a) protoplasmic (b) cellular grade (a) Star fish (b) Jelly fish
(c) tissue grade (d) organ system (c) Earthworm (d) Sponge
(4) Amoeba is a animal. *(17) Which of the following animals can regenerate
(a) symmetrical (b) Bilaterally symmetrical it’s broken body part?
(c) radially symmetrical (d) asymmetrical (a) Cockroach (b) Frog
(5) Radial symmetry is observed in . (c) Sparrow (d) Star fish
(a) Amoeba (b) Octopus *(18) Bat is included in which class?
(c) Starfish (d) Fish (a) Amphibia (b) Reptilia
(6) The animals with three germ layers are called (c) Aves (d) Mammalia
. (19) has the power of regeneration.
(a) Diploblastic (b) Monoblastic (a) Cockroach (b) Star fish
(c) Triplet (d) Triploblastic (c) Frog (d) Sparrow
Animal Classification 109

(20) Phylum has acoelomate type of (8) Amphibians

body cavity. Ans. The animals which can live in water as well as on
(a) Annelida (b) Aschelminthes land are called amphibians.
(b) Cnidaria (d) Mollusca (9) Acoelomate
(21) Exoskeleton is absent in class Ans. The multicellular animals which do not have
(a) Pisces (b) Aves body cavity are called acoelomate.
(b) Mammalia (d) Amphibia (10) External Fertilization
Ans. ( 1) (c) Aristotle (2) (a) Non-chordates (3) (b) Cellular Ans. If the union of male and female gametes takes
grade (4) (d) Asymmetrical (5) (c) Starfish (6) (d) place outside the bodies of both organisms, then
Triploblastic (7) (a) Platypus (8) (c) Fish (9) (d) the fertilization is called as external fertilization.
Setae (10) (b) homeotherms (11) (a) Amphibia (12)
(11) Ectoparasites
(a) Acoelomate (13) (d) Echi-noderms (14) (a) Frog
(15) (a) Collar cells (16) (c) Earthworm (17) (d) Ans. The parasites which live on the body of the host
Star fish (18) (d) Mammalia (19) (b) Starfish are called ectoparasites.
(20) (b) Cnidaria (21) (d) Amphibia (12) Cellular grade organization
Q.2.1. Define the following: Ans. In case of multicellular animals, if tissues are
(1) Animal Classification not formed, their body organization is called as
Ans. Formation of groups and sub-groups of animals ‘cellular grade organization.’
depending upon similarities and differences (12) Sedentary animals
among animals is called as animal classification. Ans. The animals which are attached to substratum
(2) Notochord and do not show locomotion are called sedentary
Ans. The long, rod like supporting structure present on animals.
dorsal side of an animal body is called notochord. (13) Segmented body
(3) Warm blooded animals
Ans. If a body of an animal is divided into small, similar
Ans. The animals which can maintain their body units, then such a body is called segmented body
temperature constant irrespective of surrounding and each units is called segment.
temperature are called warm blooded animals or
(14) Coelom or body cavity
homeotherms.
(4) Chordata Ans. The cavity between the body and internal organs
is called coelom or body cavity.
Ans. The animals which have dorsal, supporting
notochord in their bodies are called chordates. Q.2.2. Write short notes on:
(5) Diploblastic animals (1) Germ layers.
Ans. The multicellular animals which have two germ Ans.
layers, namely ectoderm and endoderm that are (i) In case of multicellular animals, germ layers are
formed during initial period of their embryonic formed during initial period of their embryonic
development, are called diploblastic animals.
development.
(6) Triploblastic animals
(ii) These germ layers further develop to form
Ans. The multicellular animals which have three
different tissues of the body.
germ layers, namely ectoderm, mesoderm and
(iii) In case of some animals, there are only two germ
endoderm, formed during initial period of their
embryonic development are called triploblastic layers, namely ectoderm and endoderm. They
animals. are called diploblastic animals. e.g. Cnidarians.
(7) Hermaphrodite (iv) In most of all the remaining animals, three germ
Ans. The animals which have both, male and female layers are formed, namely ectoderm, mesoderm
reproductive systems in the same body are called and endoderm, These animals are called
hermaphrodites. triploblastic. e.g. Platyhelminthes onwards all.
110 Master Key Science and Technology Part-2 (Std. X)

(v) Germ layers play major role in initiation of (4) Advantages of animal classification OR State
formation of tissues and organs in the body. the importance of animal classification OR
Give reason - There is a need for classification
Endoderm of animals.
Ans.

Ectoderm
(i) Study of animals becomes convenient.
(ii) Study of few animals from group helps to
Dead layer Mesoderm understand about the entire group.
(iii) Classification gives an idea about evolution of
Fig 6.1. Diploblastic and triploblastic
animals.
(2) Body Cavity (Coelom).
(iv) Animals can be easily identified with great
Ans. accuracy.
(i) The cavity between the body and internal organs (v) It helps to understand various adaptations shown
is called body cavity or coelom. by them.
(ii) For multicellular animals, during initial period of (vi) It helps to understand the relationship of animals
their embryonic development, the body cavity is with other living organisms.
formed either from the mesoderm or gut. Such
(vii) It helps to understand the habitat of each animal
cavity is present in animals of phylum Annelida
and its exact role in nature.
and all phyla coming after Annelida. Such
animals are called ‘eucoelomate’ (animals with Q.2.3. Complete the following chart as per the given
true body cavity). information:

(iii) In some multicellular animals, the body cavity *(1)

is absent. They are known as ‘acoelomate’ e.g. Sr.
Body cavity Germ layers Phylum
Porifera, Cnidaria, Platyheminthes. No.

(iv) In Aschelminthes, the body cavity is formed in (1) Absent Diploblastic Porifera
a different way than normal. Those animals are (2) Absent Triploblastic Platyhelminthes
called pseudocoelomates.
(3) Pseudocoelom Triploblastic Aschelminthes
(3) Body Symmetry.
Ans. (4) Present Triploblastic Arthropoda
(i) If body of any animal is cut through an imaginary *(2)
axis, it may or may not produce two equal halves.
Sr.
Depending upon this property, these are different Class Features Examples
No.
type of animal bodies.
Jaw-less mouth
(ii) In some animals, there is no such imaginary axis (1) Cyclostomata provided with Petromyzon
of the body through which we can get two equal sucker
halves. Such a body is called as asymmetrical Respiration by
(2) Pisces Pomfret
body e.g. Amoeba, Paramoecium, some sponges. Gills
(iii) In some animals, if imaginary cut passes through Can live in water
the central axis but any plane of the body, it gives (3) Amphibia Frog
and on land
two equal halves. Such a symmetry is known a
radial symmetry e.g. Starfish. Presence of
(4) Mammalia Whale
mammary glands
(iv) In some animals, there is only one imaginary axis
of body through which we can get equal halves. Cold blooded,
It is known as bilateral symmetry. e.g. Insects, (5) Reptilia Python
creeping movement
fish, frog, birds, human, etc.
Animal Classification 111

(3) Complete the following table. (2) Petromyzon

Sr. Organ for Ans.
Animal Phylum/ Class
No. locomotion 3
2
(1) Earthworm Setae Annelida 1
(2) Starfish Tube feet Echinodermata

(3) Paramoecium Cilia Protozoa 4

Fig 6.3. Petromyzon
Jointed
(4) Crab Arthropoda
appendages Ans. (1) Body (2) Gill slits (3) Eye (4) Sucker
(5) Pigeon Wings Aves (3) Nereis
Ans.
(4) 1
2
Chordates Non - Chordates
3
(1) Notochord Present Absent
4
(2) Heart Dorsal Ventral
(3) Pharyngeal gill-silts Present Absent

(5)
Body Symmetry

Fig 6.4. Nereis

Definition
Ans. (1) Tentacle (2) Mouth (3) Anus (4) Parapodia
Imaginary axis of body which may divide the (4) Germ layers
organism in two equal halves. Ans.
1
Types

Asymmetrical Radial Bilateral

2
Symmetry Symmetry

(Example) (Example) (Example) 3

Amoeba Starfish Frog Ans. (1) Endoderm (2) Ectoderm (3) Mesoderm
(5)
Q.2.4. Label the following diagrams:
(a) (b)
(1) Herdmania
Ans.
1 2

4 (c) (d)

Fig 6.2. Herdmania

Ans. (1) Branchial aperture (2) Atrial aperture (3) Tunic
(4) Body (5) Foot Ans. (a) Jelly Fish (b) Nereis (c) Planaria (d) Scoliodon
112 Master Key Science and Technology Part-2 (Std. X)

*(6) Name the body parts in the following diagram *(2) How may be the leech used in ayurvedic
Ans. system of treatment? (Get information; Text Book
Page no. 69)
1
Ans.
6 (i) According to Ayurveda leech therapy is a method
7 in which localised impure blood is let out to heal
2
the tissue.
8
(ii) Leechs used to relieve venous congestion and for
3
9 improved blood circulation.
4 (iii) Leech therapy is used in diseases like varicose
veins, arthritis, Herpes, Psoriasis, Vascular
5 10 problems, Diabetic wounds, non-healing
ulcers, etc.
*(3) Animals like ghariyal and crocodile live in water
as well as land. Are they amphibians or reptiles?
(Use your brain power; Text Book Page no. 74)
Ans.
(i) Crocodiles and ghariyals are reptiles. Crocodiles
Fig 6.5. Organ- System grade of organization and ghariyals breathe through lungs both on
Ans. (1) Brain (2) Lungs (3) Liver (4) Bone of forehand land and in water.
(5) Thigh (6) Mouth (7) Heart (8) Arm bone (9) Kidney (ii) They have dry scaly skin.
(10) Thigh muscle. (iii) They lay leathery soft eggs on land.
(7) Cockroach (iv) Amphibians have moist skin with no scales.
Ans. (v) They lay eggs in water which hatch into larve that
1 2 3
metamorphose from an aquatic to air-breathing
form.
(vi) They breathe through their skin when in water
4 and through lungs when on land.
6 *(4) Animals like whale, walrus live in water
5
(ocean). Whether they are included in pisces or
Fig 6.6. Cockroach mammalia? (Use your brain power; Text Book Page
Ans. (1) Wings (2) Thorax (3) Head (4) Antenna (5) Legs no. 74)
(6) Abdomen Ans.
Q.2.5. Answer the following: (i) Whales and walrus are included in mammalia.
They are aquatic mammals.
*(1) Which criteria are used for classification of
organisms? (Can you recall; Text Book Page no. 61) (ii) They are walm blooded animals.
(iii) They breath air and mothers feed their babies
Ans. Criteria used for classification of animals.
through mammary glands just like humans do.
(i) Presence or absence of Notochord and nerve cord
(iv) Fishes (Pisces) are cold blooded animals and
(ii) Grades of organization breathe through their gills and do not have
(iii) Body symmetry mammary glands.
(iv) Germ layers *(5) What is chitin?
(v) Body cavity (Coelom) Ans.

(vi) Body segmentation (i) Chitin is a fibrous substance consisting of

Polysaccharides.
(vii) Ability to obtain nutrients
(ii) It forms the exoskeleton of arthropods and cell
(viii) Modes of reproduction.
walls of fungi.
Animal Classification 113

Q.2.6. Distinguish between:

*(1) Butterfly and Bat
Ans. Butterfly Bat
(i) Butterfly belongs to Non-chordates. (i) Bats are Chordates.
(ii) Butterfly belongs to Phylum Arthropoda. (ii) Bat belongs to phylum Chordata.
(iii) It belongs to Class Insecta. (iii) It belongs to Class Mammalia.
(iv) Exoskeleton is chitinous. (iv) Exoskeleton is covered with hair.
(2) Non-Chordates and Chordates
Ans. Non-chordates Chordates
(i) Notochord is absent. (i) Notochord is present at some stages.
(ii) The heart if present is dorsal in position. (ii) The heart is ventral in position.
(iii) They do not posses pharyngeal gill-slits. (iii) They posses pharyngeal gill-slits.
(iv) Nerve cord if present is double, ventral and solid. (iv) Nerve cord is single, dorsal and hollow.
(3) Platyhelminthes and Aschelminthes
Ans. Platyhelminthes Aschelminthes
(i) Body is slender and flat like a leaf or strip. (i) They have long, thread like or cylindrical body.
(ii) They are also known as flat worms. (ii) They are known as round worms.
(iii) They are hermaphrodite. (iii) They are unisexual.
(iv) They are acoelomate. (iv) They are pseudocoelomate.
(4) Mollusca and Echinodermata
Ans. Mollusca Echinodermata
(i) Molluscs are soft bodied and slimy. (i) The body is rough with calcareous spines.
(ii) Body shows bilateral symmetry. (ii) Body show radial symmetry in adult stage.
(iii) They are either marine or fresh water animals. (iii) They are exclusively marine animals.
(iv) Locomotion with ventral foot. (iv) Locomotion with tube feet.
(5) Pisces and Amphibia
Ans. Pisces Amphibia
(i) These animals are totally aquatic, living in (i) Amphibians can live in water and also on the land.
marine or fresh water.
(ii) Skin is covered with scales. (ii) Skin is without any exoskeleton.
(iii) Respiration is carried out with the help of gills. (iii) Respiration is carried out mostly through skin.
(iv) Heart is two chambered. (iv) Heart is three chambered.
(6) Reptilia and Mammalia
Ans. Reptilia Mammalia
(i) Skin is dry and covered with scales. (i) Skin is covered with hair, or fur.
(ii) They are cold-blooded animals. (ii) They are warm blooded animals.
(iii) Heart is incompletely four chambered. (iii) Heart is completely four chambered.
(iv) Pinna or external ear is absent. (iv) Pinna or external ear is present.
114 Master Key Science and Technology Part-2 (Std. X)

(7) Urochordata and Cephalochordata

Ans. Urochordata Cephalochordata
(i) Notochord is present only in tail region of the (i) Notochord is present throughout the body length.
larvae.
(ii) Urochordates are hermaphrodites. (ii) Cephalochordates are unisexual.
(8) Male Ascaris and Female Ascaris
Ans. Male ascaris Female ascaris
(i) It is a short cylindrical worm. (i) It is a long cylindrical worm.
(ii) Male is thinner than female. (ii) Female is thicker than male.
(iii) Male shows a curved tail. (iii) Female has a straight tail.
(9) Cyclostomata and Pisces
Ans. Cyclostomata Pisces
(i) The skin is soft and without any scales. (i) The skin shows presence of scales.
(ii) Endoskeleton is cartilagenous. (ii) Endoskeleton is cartilagenous or bony.
(iii) Most of them are ectoparasites. (iii) They are free living.
(iv) These animals have jaw-less mouth. (iv) These animals have mouth with presence of jaws.
(10) Mammalia and Aves
Ans. Mammalia Aves

(i) Mammary glands are present. (i) Mammary glands are absent.
(ii) Mammals are mostly adapted for terrestrial (ii) Aves are completely adapted for aerial life.
life.
(iii) Limbs are used for walking and running. (iii) Forelimbs are modified into wings for flying.
(iv) Body is covered with hair or fur. (iv) Body is covered with feathers.
(v) They are viviparous. (v) They are oviparous.

Q.2.7. Write the characteristics of following animals (iv) Skin shows presence of scales.
with reference to their classification: (v) Respiration occurs with gills.
Rohu, Grasshopper, Elephant, Penguin, *(2) Grasshopper
Crocodile, Frog, Lizard, Jelly fish, Centipede,
Balanoglossus, Amphioxus, Herdmania,
Petromyzon, Bat, Bathsponge.
Ans.
*(1) Rohu

Fig 6.8. Grosshopper

(i) Grasshopper belongs to phylum Arthropoda.
(ii) Body is covered with chitinous exoskeleton.
Fig 6.7. Rohu (iii) Body is divided into head, thorax and abdomen.
(i) Rohu belongs to class pisces. (iv) There are two pairs of wings and three pairs of
(ii) It is found in fresh water. jointed appendages for locomotion.
(iii) It is a bony fish. (v) It is bilaterally symmetrical
Animal Classification 115

*(3) Elephant (i) Crocodile belongs to class Reptilia.

(ii) Skin is dry and scaly.
(iii) It is a cold-blooded (Poikilothermic) animal.
(iv) Body is divided into head, neck, trunk and tail.
(v) Crocodiles are oviparous.
(vi) It creeps on land.
*(6) Frog
(i) Frog belongs to class Amphibia.
Fig 6.9. Elephant
(ii) Can live in water as well as on land during
(i) Elephant belongs to class mammalia. adult life.
(ii) Body shows differentiation into head, neck, trunk (iii) Skin is without any exoskeleton and is usually
and tail. kept moist for respiration.
(iii) Mammary glands are present. (iv) They have two pairs of appendages. Digits are
(iv) The heart is four chambered. without claws.
(v) Largest terrestrial mammal. (v) External ear is absent but tympanum (external
(vi) It is warm-blooded. hearing structure) is present.
(vii) Body is divided into head, neck, trunk and tail. *(7) Lizard
(i) It belongs to class Reptilia.
*(4) Penguin
(ii) It is cold-blooded (Poikilotherm)
(iii) It shows creeping movement as body cannot be
lifted up.
(iv) Neck is present between head and trunk.
(v) External ear is absent.
*(9) Jellyfish
(i) Jelly fish belongs to Phylum Coelenterata.
(ii) Cnidoblast bearing tentacles are present around
the mouth. Tentacles are useful for capturing the
Fig 6.10. Penguin prey whereas cnidoblasts inject the toxin in the
body of the prey.
(i) This animal belongs to class Aves.
(iii) Body is umbrella shaped, hence called Medusa.
(ii) They are found at the south pole, i.e. at Antarctica,
which is a cold region (iv) It is diploblastic, and shows radial symmetry.
(iii) Exoskeleton shows feathers. (10) Centipede
(iv) Penguin is warm-blooded. (i) Centipede belongs to phylum Arthropoda.
(v) They are adapted to a cold region life. (ii) Body shows many jointed appendages.
(vi) Penguin is oviparous. (iii) Centipede is triploblastic and eucoelomate and
bilaterally symmetrical.
(vii) Neck is present between head and trunk.
(iv) Chitinous exoskeleton is present around their
(5) Crocodile
body.
(v) It is unisexual.
(11) Balanoglossus
(i) Balanoglossus belongs to phylum Hemichordata.
(ii) Notochord is present in proboscis region.
(iii) Marine animal lives in burrows in sand.
(iv) It is a unisexual animal.

Fig 6.11. Crocodile (v) It has pharyngeal gill slits.

116 Master Key Science and Technology Part-2 (Std. X)

(12) Amphioxus (i) Cephalochordates are small, fish-like, marine

(i) Amphioxus belongs to sub-phylum animals.
Cephalochordata. (ii) They have notochord present throughout the
(ii) Notochord is present throught the body length. body length.
(iii) Pharynx is very large and contains gill-slits. (iii) Pharynx is very large and contains gill-slits.
(iv) It is unisexual. (iv) These animals are unisexual. e.g. Amphioxus.

(13) Herdmania (3) Sub phylum Vertebrata (Craniata)

Ans.
(i) Herdmania belongs to sub-phylum-Urochordata.
(i) In these animals, the notochord is replaced by
(ii) Body is covered by skin-like test or tunic.
vertebral column.
(iii) Notochord is present only in the tail region.
(ii) Head is well developed and brain is protected in
(iv) It is a hermaphrodite. the cranium.
(14) Petromyzon (iii) Endoskeleton is either cartilagenous or bony.
(i) Petromyzon belongs to class cyclostomata. (iv) Some chordates are jaw-less (Agnatha) whereas
(ii) The skin is soft without scales. some are with jaws (Gnathostomata).
(iii) Endoskeleton is cartilagenous. (4) Class Cyclostomata
(iv) It is an ectoparasite. Ans.
(v) It has jawless mouth with suckers. (i) These are marine animals having fish-like body
(vi) Paired appendages are absent. with bilateral symmetry.
(15) Bat (ii) They have jaw-less mouth provided with sucker
(suctorial mouth).
(i) Bat belongs to class Mammalia.
(iii) Their skin is soft and without any scale.
(ii) It is adapted for aerial mode of life.
(iv) Paired appendages are absent.
(iii) Bat is a warm blooded animal.
(v) Endoskeleton is cartilagenous.
(iv) It is viviparous.
(vi) Most of the animals are ectoparasites.
*(16) Bathsponge e.g. Petromyzon, Myxine, etc.
(i) It belongs to phylum porifera. (5) Class Pisces
(ii) It bears numberous pores on its body called ostia Ans.
and oscula.
(i) They are cold blooded (Poikilotherms) aquatic
(iii) It has special type of cell-collar cells. animals living in marine and fresh waters.
(iv) It has good ability of regeneration. (ii) Body is spindle shaped to minimze water
(v) It is always attached to substratum and hence do resistance.
not show locomotion. (iii) They have paired and unpaired fins for
(vi) Its body is supported by spicules or spongin swimming. Tail fin is useful as a steering organ
fibres. while swimming.
Q.2.8. Give the characteristics of the following with (iv) Exoskeleton is in the form of scales and
examples: endoskeleton is either cartilagenous or bony.
(1) Sub phylum Urochordata (v) Respiration is carried out with the help of gills.
Ans. e.g. Rohu, Scoliodon, Pomfret, Sea horse, Electric
(i) Urochordates are marine animals. ray, Sting ray, etc.
(ii) Their body is covered by skin-like test or tunic. (6) Class Amphibia
(iii) These animals are hermaphrodites. Ans.
(iv) Notochord is present in only tail region of larvae. (i) These animals are strictly aquatic during larval
(v) e.g. Herdmania, Doliolum, Oikopleura, etc. life and perform only aquatic respiration,
(2) Sub phylum Cephalochordata whereas they can live in water as well as on land
during adult life and can perform aquatic as well
Ans.
as aerial respiration.
Animal Classification 117

(ii) They have two pairs of appendages. Digits are Q.2.9. Enlist the characteristics of the following phyla:
without claws. (1) Phylum - Porifera
(iii) Exoskeleton is absent. Skin is without any Ans.
derivative (appendages) and is always kept (i) These animals are with simplest body plan and
moist for respiration. are called as ‘Sponges’. They bear numerous
(iv) External ear is present. pores on their body. Those pores are called as
‘Ostia’ and ‘Oscula’.
(v) Neck is absent. Eyes are prominent with eye lids.
(ii) These are aquatic animals and most of them are
e.g. Frog, Toad, Salamander, etc.
marine, few are fresh water dwellers.
(7) Class Reptilia
(iii) Most of the animals have asymmetrical body.
Ans. (iv) They have special type of cells called collar cells’.
(i) According to evolution of animals, these are (v) They are non-motile, attached to a solid support.
the first true terrestrial animals with creeping Hence, referred to as sedentary animals.
movement. (vi) Their spongy body is supported by spicules or
(ii) They creep on land as their body cannot be spongin fibres. Spicules are made up of calcium
lifted up. carbonate or silica.
(iii) They are cold blooded (Poikilotherms) animals. (vii) These organisms feed upon small organisms taken
in their body along with water. Water is taken in
(iv) The skin is dry and scaly.
through ostia and given out through oscula.
(v) External ear is absent.
(viii) These animals reproduce asexually by budding
(vi) They are oviparous. or by sexual method. They also have a good
(vii) Digits are provided with claws. ability of regeneration.
e.g. Lizard, crocodile, tortoise, snake, etc. e.g. Sycon, Euspongia, (Bath sponge), Hyalonema,
Euplectella, etc.
(8) Class Aves (Birds)
(2) Phylum Coelenterata (Cnidaria)
Ans.
Ans. For diagram Refer Fig 6.12
(i) Aves are completely adapted for aerial mode of
(i) Body of coelenterates is cylindrical called ‘polyp’
life. or umbrella-like called ‘Medusa’.
(ii) Their body is spindle shaped to minimize air (ii) Most of them are marine, only few are
resistance during flight. fresh-water dwellers.
(iii) Forelimbs are modified into wings. Digits are (iii) Body is radially symmetrical and diploblastic.
covered with scales and bear claws. (iv) Cnidoblast bearing tentacles are present around
(iv) The exoskeleton is made up of feathers. mouth. Tentacles are useful for capturing the
(v) Jaws are modified into beak. prey, whereas cnidoblasts inject the toxin in the
body of prey. These are useful for protection too.
(vi) They are unisexual, oviparous animals.
e.g. Hydra, Adamsia, (Sea anemone), Physalia
(vii) They are warm blooded (Homeotherm) animals. (Portugese-man-of war), Aurelia (Jellyfish),
e.g. Peacock, parrot, pigeon, duck, penguin, etc. Corals, etc.
(9) Class Mammalia (3) Phylum Platyhelminthes
Ans. Ans.
(i) Presence of mammary glands is a typical (i) Body of platyhelminthes is slender and flat like a
character of mammalia. leaf or strip. Hence called ‘flat worms.’
(ii) Body is acoelomate, bilaterally symmetrical.
(ii) These animals are warm blooded.
(iii) Most of them are endoparasites. Few are free
(iii) Body is divided into head, neck, trunk and tail.
living and aquatic.
(iv) Digits are provided with nails, claws, or hooves.
(iv) They are triploblastic.
(v) Exoskeleton is in the form of hairs or fur. (v) These animals are hermaphrodite.
e.g. Elephant, human, kangaroo, dolphin, bat, etc. e.g. Planaria, tape worm, liverfluke, etc.
118 Master Key Science and Technology Part-2 (Std. X)

(4) Phylum Aschelminthes (Nemathelminthes) (7) Phylum - Mollusca

Ans. For diagram Refer Fig 6.15. Ans.
(i) The body of these animals is long thread-like or (i) The body of these animals is soft and slimy.
cylindrical. Hence, called as round worms. Hence, called ‘Molluscs’.
(ii) They are either free living or endoparasites. Free (ii) This is the second largest phylum in animal
living are either aquatic or terrestrial. kingdom.
(iii) These animals are aquatic or terrestrial. Most of
(iii) These animals are triploblastic and
the aquatic forms are marine, but few are fresh
pseudocoelomate.
water dwellers too.
(iv) Body is unsegmented and covered with cuticle.
(iv) Body of these animals is non-segmented,
(v) These animals are unisexual, i.e. sexes are triploblastic, eucoelomate, and soft.
separate.
(v) Except snail, their body shows bilateral symmetry.
e.g. Ascaris, (Intestinal worm), Filarial worm, Loa (vi) Body is divided into head, foot and visceral mass.
loa, (Eye worm)
(vii) Visceral mass is covered with mantle. This mantle
(5) Phylum - Annelida (Segmented worms) secretes hard, calcareous shell. This shell may be
Ans. For diagram Refer Fig 6.16. internal or external or even absent in some.
(i) The body of these animals is long, cylindrical and (viii) They are unisexual.
metamerically segmented. e.g. Snail, Octopus, Bivalve, etc.
(ii) Most of the animals are free-living, but few are *(8) Phylum-Echinodermata (Echino-spiny, derma-skin)
ectoparasites. Free living animals may be marine Ans.
or fresh water dwellers or terrestrial.
(i) Calcareous spines are present on the body of
(iii) They are triploblastic, bilaterally symmetrical these animals, hence, are called as Echinoderms.
and eucoelomate. (ii) These animals are found only in ocean.
(iv) These animals, are either hermaphrodite or (iii) Their body is triploblastic, eucoelomate. It is
unisexual. radially symmetrical in adult stage. However,
(v) They have setae, parapodia or suckers for shows bilateral symmetry in larval stage.
locomotion. (iv) They perform locomotion with the help of tube
(vi) The body is covered with special cuticle. feet. Tube feet are also useful to catch the prey.
e.g. Earthworm, Leech, Nereis etc. Some animals are sedentary.
(6) Phylum - Arthropoda (v) They have skeleton made up of calcareous spines
and /or ossicles (plates).
Ans.
(vi) These animals are unisexual.
(i) These animals have jointed appendages. Hence,
(vii) These animals have good ability of regeneration.
they are called as Arthropods.
e.g. Starfish, Brittle star, Sea-urchin, Sea cucumber,
(ii) The planet Earth has highest number of animals
etc.
from this phylum. Hence, these are the largest
(9) Phylum - Hemichordata
successful animals in the kingdom animalia.
Ans. For diagram Refer Fig. 6.18.
(iii) These animals are found in all types of habitat
ranging from deepest oceans to highest (i) Body of these animals is divided into three parts-
mountains. proboscis, collar and trunk.

(iv) Body of these animals is triploblastic, eucoelomate, (ii) Notochord is present in proboscis region only.
bilaterally symmetrical and segmented. Hence, they are called as hemichordates.

(v) Chitinous exoskeleton is present around their (iii) These animals are also called as acorn worms.
body. (iv) These are marine animals live in burrows in sand.
(vi) These animals are unisexual. (v) They have one to many pharyngeal gill slits.
e.g. Crab, spider, scorpion, millipede, cockroach, (vi) They are unisexual or some may be hermaphrodite.
centipede, butterfly, honey bee, etc. e.g. Balanoglossus, Saccoglossus.
Animal Classification 119

Q.2.10. Give scientific reasons: (iii) Reptilians have different habitat which have
*(1) Though tortoise lives on land as well as in different temperatures.
water, it cannot be included in class- Amphibia. (iv) In order to adapt to different situations, the body
Ans. temperatures of reptiles at different locations
(i) The animals which not only live in water but also differ. Hence, their body temperature is not
on land and respire in both climatic conditions constant.
are called Amphibians. (6) Frogs can live on land as well as in water.
(ii) Tortoise respires through lungs but does not have Ans.
a structure to respire in water. (i) Frog belongs to class Amphibia.
(iii) Also, tortoise lays eggs with hard shells which is (ii) Amphibians are adapted to live on land and in
a characteristic of reptiles. water.
(iv) Tortoise has a neck, whereas neck is absent in (iii) They respire with both lungs and skin.
amphibian. Therefore, tortoise is not an amphibian. (iv) When frog is on land it respires through lungs,
*(2) Our body irritates if it comes in contact with a while in water it respires through skin.
jelly fish. (v) Hence, frogs can live on land as well as in water.
Ans. (7) Digestive system is feebly developed in
(i) Jelly fish has tentacles with cnidoblasts around endoparasites.
mouth.
Ans.
(ii) The toxin released from the cnidoblasts comes in
(i) Endoparasites reside in the digestive tract of the
contact with the body of a person touching it.
host animal.
(iii) Due to this, there is an itching effect and irritation.
(ii) Thus, they suck readymade digested food from
*(3) All vertebrates are chordates but all chordates
the host body, which needs no further digestion.
are not vertebrates.
(iii) As there is no need for food to digest, their
Ans.
digestive system is feebly developed.
(i) In some chordates, the notochord is present only
(8) Birds (Aves) are adpated to aerial mode of life.
in the tail region of larvae.
(ii) In some other chordates, notochord is present Ans.
throughout the body length. (i) Birds have spindle shaped body which lowers
(iii) In some chordates, the notochord is replaced by the air resistance during flight.
vertebral column. (ii) The body is covered with light feathers.
(iv) Due to this, all chordates do not get classified in (iii) The bones are hollow, mouth is modified into
the same group. light beak.
(v) Hence, all vertebrates are chordates but all (iv) Forelimbs are modified into wings for flying in air.
chordates are not vertebrates. (v) There are air sacs which help in flight by
*(4) Balanoglossus is connecting link between non- increasing the buoyancy.
chordates and chordates. (vi) Hence, birds are adapted to aerial mode of life.
Ans. *(9) Earthworm is called as friend of farmers.
(i) Balanoglossus belongs to Hemichordata meaning Ans.
half-chordates.
(i) Earthworm feeds on dead and decaying matter
(ii) The body shows proboscis, collar and trunk.
from the soil, and digests them.
(iii) Its characteristic features resembles with
(ii) Their excreta gets mixed with soil which increases
non-chordates as well as chordates.
the nitrogen content of the soil and it becomes
(iv) Hence, it is a considered as a connecting link
fertile.
between non-chordates and chordates.
(iii) Earthworms are burrowing animals which make
*(5) Body temperature of reptiles is not constant.
the soil porous and due to this oxygen can reach
Ans.
deeper in the soil, thus soil gets aerated.
(i) Reptiles are cold blooded animals or poikilotherms.
(iv) Due to this, fertility and productivity of soil
(ii) The body temperature of cold blooded animals
increases, hence, it is called ‘Friend of Farmers’.
changes with the surrounding temperature.
120 Master Key Science and Technology Part-2 (Std. X)

(3) Poriferans are called sedentary animals. OR (2) What do you mean by ‘Notochord’? Explain.
Why are Poriferans called sedentary animals? Ans.
Ans. (i) The animals belonging to Porifera are always (i) Notochord is a long rod-like supporting structure
attached to substratum, and hence do not show present on the dorsal side of animal body.
locomotion. (ii) Therefore, they are referred as (ii) It keeps the nerve tissue isolated from the
sedentary animals. remaining body.
Q.3.1. Answer the following questions: (iii) It provides place for the muscles to attach for ease
*(1) To which phylum does Cockroach belong? of movements.
Justify your answer with scientific reasons. (iv) Animals which do not have notochord are called
Ans. Non-chordates.
(i) A cockroach belongs to phylum ‘Arthropoda’. (v) In Hemichordates, notochord is present in
proboscis region only.
(ii) A cockroach has joint appendages.
(vi) In Chordates, notochord is present in the body
(iii) Body is divided into head, thorax and abdomen. during any developmental stage.
(iv) Two pairs of wings and three pairs of limbs are (vii) In Urochordates, it is present only in tail region
present for locomotion. of larvae.
(v) It is bilaterally symmetrical. (viii) In Cephalochordates, notochord is present
(vi) A Cockroach has a pair of antenna which acts as throughout the body length.
sense organs. (ix) In Vertebrates, notochord is replaced by vertebral
(vii) It has chitinous exorskeleton. column.

*(3) How are plants classified? (Can you recall; Text Book Page no. 61)
Ans.
Kingdom Plantae

(Lack flowers,
Cryptogams Phanerogams (Have seeds)
fruits and seeds)

Thallophyta Bryophyta Pteridophyta Gymnosperms Angiosperms

Monocots Dicots
Q.3.2. Complete the following flow chart:
(1) Conventional system of Animal classification.
Ans. Kingdom Animalia

Sub Kingdom Chordates Sub Kingdom Non-chordates

Phylum- Chordata Phylum

Subphylum
Protozoa Aschelminthes
Urochordata Cephalochordata Vertebrata Porifera Annelida
Cnidaria Arthropoda
Class
Cyclostomata Platyhelminthes Mollusca
Pisces, Amphibia, Echinodermata Hemichordata
Reptilia, Aves, Mammalia
Animal Classification 121

*(2) Complete the chart - Classification of living organisms

Ans.
Living Organisms

Prokaryotic Eukaryotic

Kingdom
Monera Unicellular Multicellular

Kingdom
Protista With cell wall Without cell wall

Kingdom Animalia
Autotrophs Heterotrophs

Kingdom Plantae Kingdom Fungi

(3) Grades of Organization

Protoplasmic Cellular Cell tissue Tissue Organ Organ system

(Protozoa) (Porifera) (Cnidaria) (Platyhelminthes) (All above higher animals)

(4) Body Cavity

Body Cavity

Acoelomate Pseudocoelomate Eucoelomate

(not present) (Not a true Coelom) (Body cavity present)
eg. Porifera, Cnidaria, eg. Aschelminthes eg. Annelida to all
Platyhelminthes higher animals

(5) Phylum Chordata

Phylum Chordata

Subphylum Subphylum Subphylum

Urochordata Cephalochordata Vertebrata
(Notochord in the tail (Notochord present (Notochord replaced by
region of adult body) throughout the body length) vertebral column)
eg. Herdmania eg . Amphioxus eg Fish, frog, etc
122 Master Key Science and Technology Part-2 (Std. X)

Q.3.4. Draw well labelled diagrams and write the *(4) Ascaris (Round worm)
classification: Ans.
*(1) Hydra
Mouth
Ans.
Mouth
Tentacles Genital
Testes aperture

Mouth
Body

Ovary New bud

Female Ascaris
Male Ascaris

Fig. 6.12. Hydra hole

hole
Classification:
Kingdom : Animalia
Sub kingdom : Non-chordata Tail Tail
Phylum : Coelenterata
*(2) Jellyfish Fig.6.15. Ascaris
Ans. Classification:
Tube Bell
Gonads Kingdom : Animalia
Muscle ring Sub kingdom : Non-chordata
Tentacle Phylum : Aschelminthes
Intestine *(5) Earthworm
Ans. Segment
Mouth Clitellum Mouth
Anus
Oral arms

Fig. 6.13. Jellyfish

Classification:
Kingdom : Animalia Fig. 6.16. Earthworm
Sub kingdom : Non-chordata Classification:
Phylum : Coelenterata Kingdom : Animalia
*(3) Planaria Sub kingdom : Non-chordata
Ans. Gastrovascular
Phylum : Annelida
Cavity Pharynx *(6) Octopus
Ans.
Siphon Eye
Mouth
Eye spot
Nerve cord
Ganglia
Fig. 6.14. Planaria
Classification: Tentacles Sucker
Kingdom : Animalia
Sub kingdom : Non-chordate Fig. 6.17. Octopus
Phylum : Platyhelminthes
Animal Classification 123

Classification: Classification:
Kingdom : Animalia Kingdom : Animalia
Sub kingdom : Non-chordata Phylum : Chordata
Phylum : Mollusca Sub phylum : Vertebrata
(7) Balanoglossus Class : Amphibia
Ans. Proboscis *(10) Wall Lizard
Ans. Scaly skin Eyes
Collar
Tail

Legs
Fig. 6.21. Wall lizard
Trunk
Classification:
Kingdom : Animalia
Fig.6.18. Balanoglossus Phylum : Chordata
Classification: Sub Phylum : Vertebrata
Kingdom : Animalia Class : Reptilia
Sub kingdom : Non-chordata *(11) Pigeon
Phylum : Hemichordata Ans.
Eye
*(8) Shark Head
Beak
Ans.
Lateral line Dorsal fin Neck
Wings Tail
feathers
Eye

Caudal
Ventral fin fin
Mouth Abdomen
Pelvic fin
Gill slits Pectoral fin Claws
Fig. 6.19. Scoliodon (Dog fish) Fig. 6.22. Pigeon
Classification: Classification:
Kingdom : Animalia
Kingdom : Animalia
Phylum : Chordata
Phylum : Chordata
Sub Phylum : Vertebrata
Sub Phylum : Vertebrata
Class : Pisces
Class : Aves
*(9) Frog
(12) Bat
Ans. Eyes Nares
Tympanum Ans.
Trunk Eyes

Soft skin Mouth

Fore arm Patagium

Body

Leg Legs
Fig. 6.20. Frog
Fig. 6.23. Bat
124 Master Key Science and Technology Part-2 (Std. X)

Classification: Classification:
Kingdom : Animalia Kingdom : Animalia
Phylum : Chordata
Phylum : Porifera
Sub Phylum : Vertebrata
(16) Liverfluke
Class : Mammalia
Ans. Mouth
(13) Butterfly Oral Sucker
Ans. Genital
Antennae
Aperature
Vertral
Head Sucker
Forewing Thorax

Leaf
Abdomen like
body
Hindwing

Fig. 6.24. Butterfly

Classification:
Excretory
Kingdom : Animalia pore
Sub kingdom : Non-chordata
Fig. 6.27. Liverfluke
Phylum : Arthropoda
(14) Starfish Classification :
Ans. Kingdom : Animalia
Central disc
Sub kingdom : Non-chordata
Phylum : Echinodermata
Tubefeet
Q.4. Answer the following questions in brief:
*(1) Write in brief about progressive changes in
animal classification?
Arm Spines Ans.
(i) There are nearly seven million different species
of animals which show a lot of diversity. Hence,
Fig. 6.25. Starfish it is impossible to study them together.
Classification: (ii) Many scientists tried to classify animals into
Kingdom : Animalia various groups.
Sub kingdom : Non-chordate (iii) Greek philosopher Aristotle was the first to
Phylum : Echinodermata perform animal classification.
(15) Sycon (iv) Aristotle classified animals according to the
Ans. criteria like body size, habits and habitats.
Outlet (Osculla) Classification proposed by Aristotle is known as
‘Artificial method’.
(v) Besides Aristotle, the ‘Artificial method’ was
followed by Theophrastus, Pliny, John Ray,
Linnaeus, etc. Later on ‘Natural system of
classification’ was followed.
(vi) ‘Natural system of classification’ was based on
various criteria like body organization, types of
cells, chromosomes, bio-chemical properties etc.
(vii) With time, system of classification based on
evolution was also brought into practice. It was
Fig. 6.26. Sycon used by Dobzhansky and Meyer.
Animal Classification 125

(viii) Recently, Carl Woese has proposed the animal *(3) What types of benefit and harm occur to human
classification. In this way, the classification from animals of phylum Arthropoda? (Lets
methods of animals shows progressive changes. Think; Text Book Page no. 70)
*(2) What is the exact difference between grades Ans. Benefits of Arthropoda.
of organization and symmetry. Explain with (i) Man eats prawns, lobsters, crabs which are highly
examples. proteinaceous and have minerals. It is really a
Ans. nutritious food. The business of rearing these is
(i) Grades of organization is the structural profitable.
organization of animals whereas symmetry is (ii) Honey bees produce honey and bee wax which
whether the animals body can be divided into have many advantages.
equal halves when cut through an imaginary (iii) Silk worms, lac insects supply useful products
axis. like silk and lac respectively.
(ii) In the grades of organization, unicellular organisms (iv) Many insects bring about pollination which helps
have ‘Protoplasmic grade organization’. in agricultural practices.
(iii) In multicellular organisms, there are different Disadvantages of Arthropoda.
grades of organization, namely ‘Cellular grade’,
(i) Animals like scorpion, honey bee can bite humans
‘Cell-tissue grade’. In some animals, there is
which harms the body.
‘Tissue-organ grade organization’, while higher
(ii) Insects like mosquito spread malaria, dengue.
animals have organ system grade organization’.
Bed bugs, lice are ectoparasites and cause various
(iv) Examples: ‘Protoplasmic grade organization’ -
disorders in human body.
Amoeba
*(4) Why has it been said that only insects directly
Cellular grade organization - Porifera
compete with humans for food?
Cell-tissue grade organization - Cnidarians.
Ans.
Tissue - organ grade organization -
(i) The food that insects derive is concerned with
Platyhelminthes.
human activities. Stored food grains, pulses etc
Organ - system grade organization - All higher are easily attacked by insects.
animals.
(ii) Cockroach eats almost everything that human
(v) Depending upon symmetry, animals are can have, hence they struggle to achieve it from
Asymmetrical, Radially symmetrical and human beings.
Bilaterally symmetrical animals.
(iii) Agricultural crops get affected by pests which
(vi) Examples: Asymmetrical - Amoeba are insects. Human being uses pesticides which
Radially symmetrical - Starfish affects the pests and their struggle to get food
Bilalateral symmetrical - Cockroach, man. increases.
(vii) Grades of organization is concerned with the (iv) Use of mosquito repellents, fly traps make life of
structure of animals and this has no relation with such arthropods difficult.
symmetry. Hence, it is said that insects directly compete
with humans for food.
 126

Characteristics of Non-Chordates
Phylum Habitat Body structure Reproduction Locomotion Special features Examples
Porifera Aquatic : Marine/ Simplest body plan, � Asexual Sedentary locomotion � Special cells: Sycon, Euspongia (Bath
fresh water Assymmetrical reproduction: (attached to � Spongy body supported sponge) Hyalonema,
body with many budding substratum) by spicules spongin fibres: Euplectella
pores on body. � Sexual CaCO3 and Silica
reproduction/
Regeneration
Cnidaria or Aquatic : Mostly Cylindrical/ Asexual/sexual Sedentary free Cnidoblast bear (stinging Hydra, (Sea anemone)
Coelenterata marine/few fresh umbrella like: swimming cells) tentacles. It is use for (Portuguese man of war)
water Polyp/Medusa capturing prey. Physalia Jellyfish, Corals,
etc.
Platyhelminthes Free/living/ Slender, Leaf like Bisexual/sexual Swimming Flat body is a typical character Planaria, Liver fluke,
parasitic/ flat bodies animals Tapeworm, etc.
terrestrial aquatic
Aschelminthes Endoparasitic free Cylindrical, long Unisexual/sexual Swimming Non-segmentated bodies Ascaris (Round worm
living thread like animals with cuticle. Filarial worm Loa loa
(Eye worm)
Annelida Free swimming Metameric Bisexual/sexual Setae, Parapodia and Special cuticle over body Earthworm Nereis, Leech.
marine, terrestrial segmented body animals Suckers creeping
, few ectoparasitic cylindrical mode
Arthropoda Ranging from Different types of � Sexual/unisexual Swimming/creeping � Largest animal phylum Crab, prawn, spiders,
deepest oceans to body structures, like animals � Chitinous exoskeleton, scorpions. All insects
highest mountains hard exoskeleton, � Metamorphosis: jointed paired appendages (cockroach, butterfly,
eight legged, flying Egg, à larvae à à and segmented body. ants), Centipede,
insects, etc. pupae à adult Millipede.
Mollusca Marine/fresh Soft bodies, Slimy, Unisexual/sexual Swimming/creeping � Body divisions: Head, Oyster, Bivalves, Snail,
water/terrestrial Some have shells animals by foot foot and visceral mass. Octopus, etc.
� Second largest animal
phylum
Echinodermata Only marine Skeleton of � Sexual � Some sedentary Spiny bodies with oral and Star fish, Sea urchin,
calcareous spines, � Good � Some swim aboral surfaces. Brittle star, Sea
radial animals regeneration cucumber
� Some creep by
capacity tube feet.
Hemichordata Only marine � Proboscis collar Sexual/Unisexual Burrowing in sand. � Connecting link between � Balanoglossus,
and trunk. bisexual animals the nonchordates and � Saccoglossus
� Notchord in chordates commonly called acron
probosciis � Presence of pharyngeal worms.
gill slits.
Master Key Science and Technology Part-2 (Std. X)
 Characteristics of chordates
Class Habitat Body structure Appendages Mode of Resproduction Temperature Examples
respiration Regulation
Cyclostomata � Aquatic : � Soft skin, no scales � Paired � Gills � Oviparous � Cold � Petromyzon,
Ectoparasite/ � Jaw less mouth appendages (lays eggs) blooded Myxine, etc.
marline
Animal Classification

and sucker
Pisces � Aquatic: � Exoskeleton: Scales � Paired � Gills � Oviparous � Cold � Scoliodon,
Marine/fresh � Endoskeleton: and unpaired (lays eggs) blooded pomfret,
water Cartilage/bones appendages Bombay duck.
Sea horse,
� Stream lined body
Electric ray, etc.
Amphibia � Land and water � No exoskeleton �
Two pairs of � When in � � Cold � Frog, Toad,

� Soft and moist skin limbs water Tadpole/ Metamorphosis: blooded Salamandar, etc
larvae: gills E.g. Larva, adult
� Body differentiated
Adult: Gills
into head and trunk
� When on and:
� lungs

Reptilia � Mainly � Skin is dry and � Two weak � Lungs � Egg, young, � Warm � Tortoise,
terrestrial, some scaly pairs of limbs adult blooded lizard, snake, etc.
aquatic � Body
differentiated into
head, neck and trunk
Aves � Terrestrial, � Exoskeleton in � Forelimbs � Lungs (air � Oviparous � Warm � Peacock,
some fly form of feathers modified into sacs) (lays eggs) blooded Parrot, Crow,
� Streamlined body feathers � Parental care Duck, Penguin,
etc.
� Body
differentiated into
head, neck and trunk
Mammalia � Mainly � Exoskeloton in � Two pairs of � Lungs � Majority � Warm � Kangaroo,
terrestrial, some form of hair, fur, limbs: hands/legs (Diaphragm) viviparous, few blooded Dolphin, Bat,
aquatic, few aerial wool oviparous (lays Dog, Human, etc.
� Body eggs)
differentiated into
head, neck, torso and
tail
127

vvv
128 Master Key Science and Technology Part-2 (Std. X)

ASSIGNMENT - 6
Time : 1 hr. Marks : 20

Q.1. (A) Answer the following: (3)

(1) Fill in the blank :
.................. is considered as connecting link between Non-chordates and chordates.
(2) State True or False : Arthropods are hermaphrodites.
(3) Find the odd one out : Bat, Whale, Monkey, Ostrich.
Q.1. (B)Choose and write the correct option: (2)
(1) Amoeba is a .................. animal.
(a) Symmetrical (b) Bilaterally symmetrical (c) Radially symmetrical (d) Asymmetrical
(2) In .................., the fertilization is external.
(a) Frog (b) Bat (c) Snake (d) Parrot
Q.2. (A) Answer the following questions: (Any 2) (4)
(1) Distinguish between : Bat and Butterfly
(2) Classify the following:

(3) Complete the following table:
Animal Organ for locomotion Example

(1) Arthropoda
(2) Pigeon

Q.3. Answer the following questions: (Any 2) (6)

(1) A B
(1) Identify the animal
(2) Label parts A and B
(3) Write the function of A

(2) Write the characteristic of Penguins with reference to their classification.

(3) Draw a neat labelled diagram of Hydra.
Q.4. Answer the following: (Any 1) (5)
(1) Write in brief about progressive changes in animal classification.
(2) Enlist benefits and harm occuring to humans from animals of Phylum Arthropoda.
vvv
 7 Introduction to Microbiology
CONCEPT MAP
(1) (2)
Molecular biology Fermentation of
carbon compounds
Applied Applied
Proteins Yeast Saccharomyces cerevisiae
Genetics Microbiology
Ethanol
Study of enzymes related to some prokaryotic Microbial
and eukaryotic microbes. Acetobacter + Glucanobacter
degradation
Acetic acid
(3) Yoghurt
Bleaching Potassium ferrocynide

Probiotics Milk Butter SO2

Cheese Kefir Vinegar

(4)
Biofuels

Solid Liquid Gaseous

coal dung alcohol vegetable oil gobar gas coal gas

(5) Microbes

used for the production of

Food Products Microbial Organic Acids Amino Antibiotics Fuels Microbical Farming
Enzymes Acids Pollution
control

Examples Examples Examples Examples Examples Examples

• Dairy Products • Oxido-reductase • Citric acid L-glutamic • Pencillin • Methane • Landfilling • Microbial
• Yoghurt • Transferase acid • Cephalosporins • Ethanol • Sewage isoculants
• Gluconic acid
• Butter • Hydrolase • Monobactam • Hydrogen management • Bioinsect-
• Lactic acid gas icides
• Cheese • Lyases • Bacitracin • Clean
• Isomerase • Itaconic acid • Erythromycin • Other Technology
• Probiotics
• Bread • Ligases • Neomycin Biofuels
• Beverage • Streptomycin
• Vinegar • Tetracyclins
• Vancomycin

(129)
130 Master Key Science and Technology Part-2 (Std. X)

Points to Remember:
�  pplied Microbiology is a branch of biology which studies the enzymes related to some prokaryotes and
A
eukaryotic microbes, proteins, applied genetics, molecular biology, etc is performed.
� Industrial Microbiology - This science is related to commercial use of microbes in which various economic,
social and environmental related processes and products are included.
� Main features of Industrial Microbiology
– Various productions with the help of fermentation process. eg. bread, cheese, wine.
Raw materials for chemicals, enzymes, nutrients, medicines, etc.
– Use of microbes for garbage management and pollution control.
� Dairy Products: Milk is converted into various products for its preservation purposes. eg. cheese, butter,
cream, kefir, yoghurt.
� Microbes play an important role in disposal of solid waste through biogas plant and compost production.
� Clean Technology : Microbes have the natural ability of decomposing the man-made chemicals.
� Biofuel is important among the renewable sources of good energy.
� Microbes are used for bioremediation of environment.
� Microbes in the inoculants help in plant growth by supplying nutrients.
� Some bacteria, fungi and viruses are useful as pesticides.

*(16) Harmful bacteria like in the intestine

MASTER KEY QUESTION SET - 7 are destroyed due to probiotics.
Q.1. (A) 1. Fill in the blanks and rewrite the (17) Acetic acid is bleached with the help of
completed statements: (18) imparts thickness to ice-creams.
(1) Cheese is produced with the help of . (19) For maintaining the protein content in yoghurt,
(2) Lactose sugar of the milk is converted into
 is mixed with milk.
. (20) Shelf life of yoghurt and its probiotic properties
(3) Diacetyl has the flavour of . can be improved by .
(4) Yoghurt is a milk product produced with the (21) An enzyme obtained from
help of . alimentary canal of cattle was traditionally used
(5) Enzyme protease obtained from fungi is used to to produce cheese.
produce  cheese. (22) For making bread, the yeast is used.
(6) Dough rises up due to . (23) Mixture of bacterial strains like
*(7) Chemically vinegar is 4% . and is mixed with ethanol for its
(8) Very small quantity of gas is mixed microbial degradation.
to produce vinegar. (24) Microbe is used for the production
(9) Rifamycin is effective against . of coffee.
(10) an alcohol is a clean fuel. (25) and syrup can be
obtained from corn flour by action of enzymes
(11) is considered to be the fuel of future.
obtained from bacilli and Streptomyces.
(12) Phenol oxidizing bacteria decompose the
(26) acid is used in paper, textile, plastic
chemicals present in sewage.
industry and gum production.
(13) , a by-product of fermentation is a
(27) acid is used for production of
biopesticide.
monosodium glutamate (Ajinomoto).
*(14) Salts which can be used as supplement of calcium
and iron are obtained from acid. (28) Polysaccharides and glycolipids are used as
.
*(15) Process of of milk proteins occurs
due to lactic acid. (29) Xylitol and aspartame are used as .
Introduction to Microbiology 131

(30) Metals are converted into compounds before Ans. Clostridium : Others are useful microbes, whereas
leaching with the help of and . Clostridium is a harmful microbe.
(31) and bacteria are used to (5) Spirulina, Chlorella, Blue green algae, Actinomycetes.
clear the oil spills. Ans. Actinomycetes : Species of fungi - others are
(32) Plastic bottles are formed from a chemical probiotic algae.
substance . (6) Chilli sauce, soya sauce, vinegar, monosodium
(33) Species like and can glutamate.
decompose PET. Ans. Chili sauce : Others are formed by microbial
(34) and can control the soil fermentation.
pollution occuring due to acid rain. (7) Oxidoreductases, tranferases, ligases, papain.
(35) convert salts of uranium into Ans. Papain - Enzyme present in papaya plant whereas
insoluble salts. others are microbial enzymes.
(36) Solution containing and (8) Penicillin, erythromycin, gentamycin, acetic acid.
is used in organic farming. Ans. Acetic acid - Others are antibiotics.
(37) chemicals are mixed with the soil (9) Actinomycetes, Streptomyces, Nocardia, Pseudomonas.
due to use of chemical pesticides in agriculture. Ans. Pseudomonas - HCB bacteria, Others are fungi
(38) Bacteria used to clear oil spills are called which decomposes rubber.
. (10) Citric acid, Malic acid, Glutamic acid, Lactic acid.
Ans. (1) Fungi (2) lactic acid (3) butter (4) lactobacilli Ans. Glutamic acid - Others are used to impart acidity
(5) vegetarian (6) CO2 (7) acetic acid (8) SO2 whereas glutamic acid is used for protein binding.
(9) tuberculosis (10) Ethanol (11) Hydrogen gas (11) Beta carotene, lycopene, xanthene, xanthan.
(12) xenobiotic (13) Spinosad (14) Gluconic acid
Ans. Xanthan - Others are used as edible colours
(15) coagulation (16) clostridium (17) potassium
whereas Xanthan gum is used to impart thickness.
ferrocynide. (18) Xanthan gum. (19) condensed
(12) Gentamycin, streptomycin, natamycin, neomycin.
milk powder (20) pasteurization (21) rennet
(22) Saccharomyces cerevisiae (23) Acetobacter, Ans. Natamycin - Others are antibiotics, whereas
Glucanobacter (24) Lactobacillus brevis (25) Glucose, Natamycin is used as microbial restrictor.
fructose (26) Itaconic acid (27) L-glutamic acid Q.1. (A) 3. Complete the correlation.
(28) emulsifiers (29) artificial sweetners (30) Thiobacilli, (1) Lactobacilli : Yogurt production : : Azotobacter :
Sulphobacilli (31) Pseudomonas spp. and Alcanovorax .
borkumensis (32) Polyethylene Terephthalate Ans. Organic farming: Yoghurt is a milk product
Polyester (PET) (33) Vibrio, Ideonella sakaiensis. produced with the help of bacteria Lactobacilli,
(34) Acidophillum spp., Acidobacillus ferroxidens while Azotobacter is used in organic farming.
(35) Geobacter (36) Azotobacter, artificial nitrogenase
(2) Ideonella sakaiensis : PET : : Actinomycetes :
(37) Fluoroacetamide like (38) Hydrocarbonoclastic
.
bacteria (HCB)
Ans. Rubber: Ideonella sakaiensis can decompose PET.
Q.1. (A) 2. Find the odd word out: Similarly, species of fungi like Actinomycetes have
(1) Cheese, kefir, yoghurt, vinegar. the ability of decomposing rubber.
Ans. Vinegar - Others are milk products (3) Phenol oxidising bacteria : Sewage ::
(2) Lactobacillus lactis, Lactobacillus delbrueckii, Hydrocarbonoclastic bacteria : .
Lactobacillus cremoris, Streptococcus thermophilus. Ans. Oil spills: Phenol oxidizing bacteria destroy the
Ans. Lactobacillus delbrueckii - Others are used in cheese Xenobiotic chemicals present in sewage, while
production, whereas Lactobacillus delbrueckii is Hydrocarbonoclastic bacteria (HCB) destroy
used in yoghurt production. pyridines and other chemicals in the oil spills.
(3) Cutting, washing, rubbing, scrubbing. (4) Enzyme rennet : Alimentary canal of cattle : :
Ans. Scrubbing : This process is not included in cheese Enzyme protease :
production. Ans. Fungi: Enzyme rennet is obtained from
(4) Acidophilus, Bifidobacterium bifidum, Clostridium, alimentary canal of cattle, whereas enzyme
Lactobacillus casei. protease is obtained from Fungi.
132 Master Key Science and Technology Part-2 (Std. X)

(5) Probiotic : Diarrhoea : : Antibiotic Rifamycin : (ii) In Industrial Microbiology, we study commercial
use of microbes in which various economic, social
Ans. Tuberculosis: Probiotics is used for treatment of and environment related processes and products
diarrhoea, whereas Rifamycin is effective against are included.
Tuberculosis. (2) Explain the difference between sweet cream
(6) Flour cereal : Bread : : Sugar molasses : butter and cultured variety of butter.
Ans. Ethanol: Flour cereal is used to produce different Ans. Cultured butter is produced by microbes, and
types of bread, whereas Ethanol is produced by sweet cream butter is produced from fresh sweet
fermentation of sugar molasses. cream.
(7) Dirt removal : Detergents : : Corn flour :
Q.1. (A) 5. Match the following:
Ans. Glucose syrup: Process of dirt removal occurs at
low temperature due to mixing of enzymes with *(1) Column A Column B
detergents, while Glucose syrup can be obtained
(1) Xylitol (a) Pigment
from corn flour by action of enzymes.
(8) Pseudomonas spp. : Oil spills :: Acidophillum spp. : (2) Citric acid (b) To impart sweetness
(3) Lycopene (c) Microbial restrictor
Ans. Soil pollution: Pseudomonas spp. destroy pyridines
(4) Nycin (d) Protein binding emulsifier
and other chemicals in the oil spills, whereas
Acidophillum spp. control the soil pollution due to (e) To impart acidity
acid rain.
Ans. (1 – b), (2 – e), (3 – a), (4 – c)
(9) Cocoa : Theobroma cacao :: Coffee :
Ans. Caffea arabica: Cocoa is produced from the fruit (2) Column A Column B
Theobroma cocoa, whereas coffee is produced from
(1) Yoghurt (a) Lactobacillus lactis
Caffea arabica.
(10) Yoghurt : Lactobacilli delbrueckii :: coffee : (2) Bread (b) Lactobacillus casei
(3) Cheese (c) Lactobacillus delbrueckii
Ans. Lactobacillus brevis: Yoghurt is produced with
(4) Kefir (d) Saccharomyces cerevisiae
the help of microbe Lactobacilli, whereas coffee is
produced with the help of microbe Lactobacillus (e) Aspergillus oryzae
brevis.
Ans. (1 – c), (2 – d), (3 – a), (4 – b)
(11) Gluconic acid : Aspergillus niger :: Itaconic acid :
(3) Column A Column B
Ans. Aspergillus itaconius: Gluconic acid is produced
with the help of microbe Aspergillus niger, while (1) Apple (a) Coffee
Itaconic acid is produced with the help of microbe (2) Grapes (b) Cocoa
Aspergillus itaconius.
(3) Theobroma cacao (c) Chocolate
(12) Polysaccharides : Emulsifiers :: Aspartame :
(4) Caffea arabica (d) Wine
Ans. Artificial sweetner: Polysaccharides obtained (e) Cider
by microbial processing is used as emulsifiers,
Ans. (1 – e), (2 – d), (3 – b), (4 – a)
whereas Aspartame is used as Artificial sweetner.
Q.1. (A) 4. Explain the difference in one sentence / (4) Column A Column B
one point. (1) Corynobacterium (a) Lactic acid
(1) Explain the difference between Applied
(2) Aspergillus niger (b) Itaconic acid
Microbiology and Industrial Microbiology.
Ans.  (3) Lactobacillus delbrueckii (c) Gluconic acid
(i) In Applied Microbiology, we study enzymes (4) Aspergillus itaconius (d) Wine
related to some prokaryotic and eukaryotic (e) L-glulamic acid
microbes, proteins, applied genetics and
molecular biology. Ans. (1 – e), (2 – c), (3 – a), (4 – b)
Introduction to Microbiology 133

(5) How are the items in group A, B, C interrelated. and Lactobacillus delbrueckii are added to warm
temperature milk in 2:1 proportion.
A B C
(7) Cheese is produced on large scale from
(1) Methane (i) Yeast - (a) Bio-photolysis
abundantly available cow milk all over the world.
fuel Saccharomyces of water
(2) Hydrogen (ii) Microbial (b) Fermentation (8) Whey is separated from yoghurt in the production
fuel anaerobic of molases of cheese.
decomposition (9)  nzyme protease obtained from fungi is used to
E
produce vegetarian cheese.
(3) Ethanol (iii) Photoreduction (c) Urban,
(10) Useful microbes become inactive due to
fuel by bacteria agricultural,
antibiotics, probiotics make them active again.
industrial
waste. (11) Ajinomoto, a popular chinese food is produced
by microbial fermentation.
Ans. (1 – ii – c), (2 – iii – a), (3 – i – b)
(12) Probiotics are used for treatment of cough and
(6) Column A Column B cold.
(1) Solid fuel (a) Vegetable oils (13) Microbial enzymes are inactive at low temperature.
(2) Liquid fuel (b) Gobar gas (14) Bio-fuel is among non-renewable source of good
(3) Gaseous fuel (c) Crop residue energy.
Ans. (1 – c), (2 – a), (3 – b) (15) I n villages, domestic sewage is disposed off in
nearby soil.
(7) Column A Column B
(16) Soyabean sauce is produced with the help of
(1) Phenol (a) Prevent leaching of fungus Aspergillus niger.
oxidising iron, zinc by forming
(17) Mozzarella cheese is very hard cheese.
bacteria compounds
(18) On storing for 3 to 12 months, very hard cheese
(2) Thiobacilli (b) Xenobiotic chemicals called Parmesan cheese is formed.
(3) Pseudomonas (c) Soil pollution due to (19) Antibiotics maintain the balance of intestinal
spp. acid rain microorganisms.
(4) Ideonella (d) Biopesticide (20) Nowadays, probiotics are used for treatment of
sakaiensis diarrhoea and treatment of poultry.
(5) Actinomycetes (e) Oil spills
(21) Acetic acid is bleached with the help of potassium
(6) Acidobacillus (f) PET permanganate.
ferroxidens (22) L-glutamic acid is used for production of
(g) Rubber monosodium glutamate (Ajinomoto).
Ans. (1 – b), (2 – a), (3 – e), (4 – f), (5 – g), (6 – c) (23) Microbes are used for bioremediation of
environment polluted due to sewage.
Q.1. (A) 6. State whether the following statements
(24) Bacteria used to clear oil spills are called phenol
are True or False. Correct the false statement.
oxidising bacteria.
(1) I ndustrial microbiology uses microbes for
Ans. (1) True (2) False. Various products like food and
garbage management and pollution control.
medicines are produced on a large scale with the
(2) Various products like food and cosmetics are help of micro-organisms. (3) True (4) False. Basic
produced on a large scale with the help of micro- process for production of yoghurt, cheese and
organisms. cream is same. (5) True (6) False. Bacterial strains
(3) Milk is converted into various products for its of Streptococcus thermophilus and Lactobacillus
preservation purpose. delbrueckii are added to warm temperature milk
(4) Basic process for production of yoghurt, cheese in 1 : 1 proportion. (7) True (8) True (9) True
and cream is different. (10) True (11) True (12) False. Probiotics are used in the
(5) Milk is pasteurized at the beginning to destroy treatment of diarrhea. (13) False. Microbial enzymes
unwanted microbes. are active at low temperature. (14) False. Bio-fuel is
among renewable source of good energy. (15) True
(6) Bacterial strains of Streptococcus thermophilus
(16) False. Soyabean sauce is produced with the help
134 Master Key Science and Technology Part-2 (Std. X)

of fungus Aspergillus oryzae. (17) False. Mozarella (16) Fungus used in production of soya sauce.
cheese is soft cheese. (18) False. On storing for 3 to Ans. Aspergillus oryzae
12 months, semi-hard cheddar cheese is formed.
(17) Microbial enzymes.
(19) False. Probiotics maintain the balance of intestinal
microorganisms. (20) True (21) False. Acetic acid Ans. Oxidoreductases, transferases, hydrolases,
is bleached with the help of potassium ferrocynide. lyases, isomerases, ligases, etc.
(22) True (23) True (24) False: Bacteria used to clear oil (18) Industries in which microbial enzymes are used.
spills are called Hydrocarbonoclastic bacteria (HCB).
Ans. Cheese, plant extracts, textile, leather, paper
Q.1. (A) 7. Name the following (19) Microbe acting on fruit apple and grapes.
(1) Fermented food items Ans. Saccharomyces cerevisiae
Ans. Bread, Cheese, Yoghurt
(20) Microbe acting on fruit Theobroma cacao.
(2) Acid present in Yoghurt
Ans. Candida, Hansenula, Pichia, Saccharomyces
Ans. Lactic acid
(21) Microbe acting on fruit Caffea arabica.
(3) Sugar present in milk
Ans. Lactose Ans. Lactobacillus brevis
(4) Dairy product produced with the help of fungi (22) Amino acid obtained from Aspergillus itaconius
Ans. Cheese Ans. Itaconic acid
(5) Bacterial strains which convert milk to Yoghurt. (23) Amino acid obtained from Lactobacillus delbrueckii.
Ans. Streptococcus thermophilus, Lactobacillus delbrueckii Ans. Lactic acid
(6) Water in Yoghurt (24) Amino acid obtained from Aspergillus niger.
Ans. Whey
Ans. Citric acid and Gluconic acid
(7) Microbes used in production of cheese.
(25) Amino acid obtained from Brevibacterium,
Ans. Lactobacillus lactis, Lactobacillus cremoris,
Corynobacterium
Streptococcus thermophilus
Ans. L-glutamic acid
(8) Enzyme from which vegetarian cheese is
produced (26) Substances which impart acidity.
Ans. Enzyme protease Ans. Citric, Malic and Lactic acid
(9) Steps for process of cheese production. (27) Substances which help in protein binding.
Ans. Cutting, washing, rubbing, salting, mixing, ripening. Ans. Glutamic acid, Lysine, Tryptophan
(10) Yeast used in commercial bakery industry. (28) Substances which are microbial restrictors.
Ans. Compressed yeast
Ans. Nycin and natamycin
(11) Ingredients of popular chinese food produced by
(29) Substances which are antioxidants and vitamins.
microbial fermentation.
Ans. Ascorbic acid (Vit. C), B12 , B2
Ans. Vinegar, soya sauce, monosodium glutamate
(12) Chemical used to impart sour taste and to (30) Substances which are edible colours.
preserve. Ans. Beta carotene, lycopene, xanthenes, lutein
Ans. Vinegar (31) Substances which are used as emulsifiers.
(13) Alcohol obtained by fermentation of carbon com- Ans. Polysaccharides, glycolipids
pounds.
(32) Substances which are artificial sweeteners (low
Ans. Ethanol calorie)
(14) Yeast used for production of Ethanol. Ans. Xylitol, aspartame
Ans. Saccharomyces cerevisiae
(33) Substances which are used as essence.
(15) Bacterial strains added to ethanol to produce
Ans. Vanillin, Ethyl butyrate (fruit flavour),
acetic acid.
peppermint flavour, essence of various fruits and
Ans. Acetobacter and Glucanobacter
flowers.
Introduction to Microbiology 135

(34) Antibiotics obtained from various strains of gram (4) bacteria present in Root nodules of
positive and gram negative bacteria. leguminous plants help in nitrogen fixation.
Ans. Penicillin, cephalosporins, monobactam, bacitricin, (a) Rhizobium (b) Azotobacter
erthromycin, gentamycin, neomycin, streptomycin, (c) Geobacter (d) Pseudomonas
tetracylin, vancomycin, etc. (5) Substance prepared by using yeast is .
(35) Solid Bio-fuel (a) bread (b) honey
Ans. Coal, dung, crop-residue
(c) butter (d) yoghurt
(36) Liquid Bio-fuel
(6) Yeast reproduces by method of
Ans. Vegetable oils, alcohol asexual reproduction.
(37) Gaseous Bio-fuel (a) spores (b) budding
Ans. Gobar gas, coal gas (c) binary fission (d) vegetative reproduction
(38) Antibiotic effective against tuberculosis. Ans. (1) (c) pasteurized (2) (c) parmesan (3) (d) recycling
Ans. Rifamycin (4) (a) Rhizobium (5) (a) bread (6) (b) budding
(39) Metals which leach into the environment from Q.2.1. Define the following terms:
low quality metalloids.
(1) Applied microbiology.
Ans. Copper, iron, uranium, zinc Ans. B
 ranch of biology in which study of enzymes
(40) Hydrocarbonoclastic bacteria (HCB) related to some prokaryotes and eukaryotic
Ans. Pseudomonas spp, Alcanovorax borkumensis microbes, proteins, applied genetics, molecular
(41) Chemical substance from which plastic bottles biology is performed is called as applied
microbiology.
are made.
(2) Industrial microbiology.
Ans. PET - Polyethylene Terephthalate Polyester
Ans. S
 cience related to commercial use of microbes in
(42) Species of bacteria which decompose PET.
which various economic, social and environment
Ans. Vibrio, Ideonella sakiensis related processes and products are included is
(43) Species of fungi which decompose rubber from called industrial microbiology..
garbage Q.2.2. Answer the following one or two Sentence:
Ans. Actinomycetes, Streptomyces, Nocardia, Actinoplanes. *(1) What for Probiotic food is famous? (Can you tell;
(44) A biopesticide Textbook Page no. 79)
Ans. Spinosad Ans. Probiotic food is famous for maintaining the
(45) Bacteria which use sulphuric acid as a source of balance of intestinal microorganisms, i.e.
energy. increasing the population of microbes helping
in digestion and decreasing the population of
Ans. Acidophillium spp; Acidobacillus ferroxidens
harmful microbes like Clostridium.
Q.1 (B) Choose and write the correct option. *(2) In the earlier class, you had prepared the
(1) Milk is at the beginning to destroy solution of dry yeast for observation of Yeast.
unwanted microbes. Which substance is prepared by its use on
(a) heated (b) cooled commercial basis? (Use your brain power; Textbook
(c) pasteurized (d) powdered Page no. 79)
(2) Very hard cheese is formed after Ans. It is used to prepare bread and vinegar.
ripening for 12 - 18 months. *(3) Which functions are performed by enzymes
(a) mozzarella (b) cheddar secreted in human digestive system? Give
names of such enzymes. (Can you tell; Textbook
(c) parmesan (d) cottage
Page no. 80)
(3) Most appropriate method of disposal of dry
Ans.
waste is .
(i) Enzymes secreted in the digestive system perform
(a) sanitary landfill (b) composting the function of digestion.
(c) incineration (d) recycling (ii) Enzyme Protease digests proteins. Enzyme
136 Master Key Science and Technology Part-2 (Std. X)

Amylase digests carbohydrates. Enzyme Lipase nodules of leguminous plants are useful?
digests fats. (Can you tell; Textbook Page no. 85)
*(4) Food materials like cold drinks, ice-creams, Ans. Rhizobium Bacteria present in soil and root
juices are available in various colours and nodules of leguminous plants fix atmospheric
flavours. Whether these colours and flavours are nitrogen and convert into nitrites and nitrates
really derived from fruits? (Use your brain power; and make it available to plants.
Textbook Page no. 81) *(12) Which plants are cultivated to obtain the fuel?
Ans. Ans.
(i) Colours and flavours are derived from fruits, (i) Crops cultivated to obtain fuel are corn,
vegetables, plants, minerals etc. sugarcane, wheat, soya beans, beet, Jatropha, etc.
(ii) Some colours are natural. Some colours are (ii) These are the main sources for the most common
artificial. types of biofuels today.
*(5) Which different materials are decomposed in a *(13) Which fuels are obtained from biomass?
bio-gas plant? (Can you tell; Textbook Page no. 82) Ans. Fuels obtained from biomass:
Ans. Agricultural waste, manure, municipal waste, (i) Solid fuels : Coal, dung, crop residue
plant material, sewage, green waste or food waste (ii) Liquid fuels : Vegetable oils, alcohol
are decomposed in a bio-gas plant.
(iii) Gaseous fuels: Gobar gas, coal gas.
*(6) Which useful materials are obtained through
*(14) Which materials should not be present in garbage
it? Which is the fuel out of those? (Can you tell;
for its proper microbial decomposition?
Textbook Page no. 82)
Ans.
Ans. Methane (CH4), carbon dioxide (CO2) and may
have small amount of hydrogen sulphide (H2S), (i) Presence of synthetic polymers and insecticides
moisture. Slurry is also obtained from the biogas will badly affect the microbial decomposition.
plant. Methane is the fuel out of those. (ii) Toxic levels of elements (Aluminium, Manganese,
*(7) Decomposition occurs through which Boron, Selenium and chlorine, excessive soluble
organisms? (Can you tell; Textbook Page no. 82) salts and organic phylotoxins) in plant materials
affect decomposition of garbage.
Ans. Decomposition occurs through bacteria and
fungi. Q.2.3. Write short notes on:
*(8) Why it is asked to segregate wet and dry waste (1) Industrial microbiology.
in each home? (Let’s think; Textbook Page no. 83) Ans. T
 his science is related to commercial use of
Ans. Waste has to be segregated as dry and wet microbes in which various economic, social and
garbage at homes because dry garbage can be environment related processes and products are
given to recycling units and wet garbage can be included. Various microbial processes useful for
converted into compost. this purpose are carried out, like:
*(9) What is done with the segregated waste? (Let’s (i) Various productions with the help of fermentation
think; Textbook Page no. 83) process e.g. bread, cheese, wine, medicines,
Ans. Dry waste is recycled, wet waste is headed to enzymes, chemicals, etc.
landfills. (ii) Use of microbes for garbage management and
*(10) Which is the most appropriate method of pollution control.
disposal of dry waste? (Let’s think; Textbook Page (2) Dairy products.
no. 83) Ans. 
Ans. (i) Since ancient days, milk is converted into various
(i) The most appropriate method of disposal of dry products for its preservation.
waste is recycling. Segregate the dry waste itself. (ii) Water content and acidity of the milk changes
Separate the commodities. during formation of these products and texture,
(ii) Commodities like glass, metals, plastic can be taste and flavour is improved.
recycled as it becomes commercial/industrial dry (iii) Bacteria in milk is used for most milk products.
waste. Milk is pasteurized at the beginning to destroy
*(11) How the bacteria present in soil and root unwanted microbes.
Introduction to Microbiology 137

(iv) These processes are performed on a large scale (ii) Condensed milk powder is mixed with milk to be
with more skill. fermented for maintaining the protein content for
(v) Milk is fermented with the help of lactobacilli. industrial production of yoghurt.
Lactose sugar of the milk is converted into lactic (iii) Milk is boiled and once it cools to warm
acid. temperature, bacterial strains of Streptococcus
(vi) Milk proteins are coagulated with the help of thermophilus and Lactobacillus delbrueckii are
lactic acid. added in 1 : 1 proportion.
(iv) Lactic acid formed due to Streptococcus makes the
(vii) Compounds with taste and flavour are also
proteins to gel out and gives dense consistency to
formed. e.g. Diacetyl has the flavour of butter.
the yoghurt.
(3) Probiotics.
(v) Acetaldehyde like compounds which are formed
Ans. due to Lactobacilli give characteristic taste to
(i) Probiotic products are available in various forms Yoghurt.
like yoghurt, kefir, sauerkraut (pickle of cabbage), (vi) Shelf life of Yoghurt and its probiotic properties
dark chocolate, miso soup, pickles, oils, corn can be improved by pasteurization.
syrup, artificial sweeteners, micro-algae (sea food
(6) Vinegar Production.
like spirulina, chlorella, blue green algae, etc.)
Ans.
(ii) These products contain active bacteria which (i) Vinegar is used in each country of the world to
increase the population of useful microbes, impart sour taste to food materials.
helping in digestion and decrease the population
(ii) It is also used for preservation of pickles, sauce,
of harmful microbes.
ketch-up, chutneys, etc.
(iii) These products form the colonies of useful
(iii) Chemically, vinegar is 4% acetic acid (CH3COOH).
microbes in alimentary canal and control other
microbes and other metabolic activities, improve (iv) Ethanol is obtained by the fermentation of carbon
resistance and lower the ill-effects of harmful compounds like fruit juices, maple syrup, sugar
substances formed during metabolic activities. molasses, starch of roots by yeast Saccharomyces
cerevisiae.
(iv) Useful microbes become inactive due to
antibiotics. Probiotics make them active again. (v) Microbial degradation of ethanol by mixture of
bacterial strains - Acetobacter and Glucanobacter
(v) Nowadays probiotics are used for treatment of
takes place.
diarrhoea and treatment of poultry also.
(vi) Acetic acid and other by-products are obtained
FUNCTIONS OF PROBIOTICS through it.
Prevents reproduction of (vii) Acetic acid is separated from mixture by
pathogenic micro-organisms. rarefaction.
Regulate the Antagonistic effect (viii) Acetic acid is bleached with the help of potassium
absorption of on harmful ferrocynide, and is then pasteurized.
minerals, gases, water. micro-organisms.
(ix) A very small quantity of SO2 gas is mixed to
Digestion of Strengthens produce vinegar.
Carbohydrate and PROBIOTIC the immune
proteins. system. (7) Microbial enzymes.
Ans.
Normalize the (i) Microbial enzymes have replaced chemical
Improved digestion
cholesterol levels.
catalysts in chemical industry. These enzymes
Produce Vitamin K, Vitamin are active at low temperature, pH and pressure;
B12 , thiamine, folic acid, biotin. due to which energy is saved and erosion-proof
instruments are also not necessary.
(4) Yoghurt.
(ii) Enzymes carry out specific processes, hence
Ans. unnecessary by-products are not formed due to
(i) Yoghurt is a milk product produced with the which expenses on purification are minimised.
help of Lactobacilli. (iii) In case of microbial enzymatic reactions,
138 Master Key Science and Technology Part-2 (Std. X)

elimination and decomposition of waste material (v) It is covered with layers of soil, saw dust, leafy
is avoided and enzymes can be reused. Therefore, waste and specific biochemicals.
enzymes are eco-friendly. (vi) Bioreactors are mixed at some places.
(iv) Oxidoreductases, transferases, hydrolases, lyases, (vii) Microbes present in the soil and other top layers
isomerases, ligases, etc. are microbial enzymes. decompose the waste.
(v) Enzymes are mixed with detergents for removal (viii) Completely filled pit is sealed with soil slurry.
of dirt at low temperature. (ix) Best quality compost is formed after few days.
(vi) Glucose and fructose syrup can be obtained from Land filling sites can be reused after removal of
corn flour by action of enzymes obtained from compost.
bacilli and Streptomyces. (11) Sewage Management.
(vii) Microbial enzymes are used in various industries Ans.
like cheese, plant extracts, textile, leather, paper, etc. (i) In villages, domestic sewage is disposed off either
(8) Xanthan gum. in nearby soil or in biogas plant.
Ans. (ii) In cities sewage is carried to processing unit for
(i) Xanthan gum is obtained by fermentation of microbial action.
starch and molasses with the help of Xanthomonas (iii) Microbes are mixed with sewage to decompose
species. compounds as well as pathogens.
(ii) It is variously useful due to properties like (iv) They release Methane and CO2 by decomposition
solubility in hot and cold water, high density, etc. of carbon compounds present in sewage.
(iii) It is used in production of pigments, fertilizers (v) Phenol oxidising bacteria decompose the
weedicides, textile pigments, tooth pastes, high xenobiotic chemicals present in sewage.
quality paper. (vi) The sludge that settles down in this process can
(iv) It imparts thickness to ice-creams, puddings, again be used as fertilizer.
chocolates, milk shakes, chocolate drinks, instant (vii) Water released after microbial treatment is
soups, etc. environmentally safe.
(9) Antibiotics. (viii) Microbes are used for bioremediation of
Ans. environment polluted due to sewage.
(i) Antibiotics are medicines obtained from bacteria (12) Clean Technology.
and fungi. Ans.
(ii) They are used to control human and animal (i) Human being has made a very fast progress in
diseases. technology.
(iii) Antibiotics like penicillin, cephalosporins, (ii) However, environmental pollution is also
erythromycin, gentamycin, neomycin, tetracyclins, increasing with the same speed.
etc. are used against various strains of gram (iii) Microbes have the natural ability of decomposing
positive and gram negative bacteria. the manmade chemicals.
(iv) Example: Rifamycin is effective against (iv) Hydrocarbons and some other chemical are
tuberculosis. transformed with the help of these abilities.
(10) Land-filling sites. (v) Some microbes remove sulphur from the fuels.
Ans. (vi) Metals like copper, iron, uranium, zinc etc.
(i) Composting is one of the best methods to dispose leach into the environment from low quality
off degradable waste accumulated in urban areas. metalloids. These are converted into compounds
(ii) Large pits are dug in open spaces far away from before leaching with the help of Thiobacilli and
the residential area. Sulphobacilli.
(iii) Pits are lined with plastic sheet/liner to avoid (13) Microbial Inoculants.
leaching of toxic and harmful materials which Ans.
pollute the soil. (i) Microbes-containing inoculants are produced by
(iv) Compressed waste is dumped in the pit. process of fermentation.
Introduction to Microbiology 139

(ii) Innoculants are sprayed on seeds before sowing Q.2.4. Complete the following concept maps:
(iii) Some innoculants are released into plants. *(1) Complete the following conceptual picture.
(iv) Microbes in the innoculants help in plant growth Ans.
Cleaning
by supplying nutrients.
(v) They improve the quality of vegetarian food.
Environmentally Sewage after Microbial
Solution containing Azotobacter and artificial
safe water processing decomposition
nitrogenase is used in organic farming.
(vi) This solution prevents soil pollution due to
chemical fertilizers. Sludge - Fertilizer

(vii) Fluroacetamide-like chemicals are mixed with *(2) Complete the following conceptual picture
the soil due to use of chemical pesticides in with respect to uses.
agriculture. These are harmful to other plants and Ans.
animals as well as cause skin diseases to humans. High quality
(viii) These pesticides in the soil can be destroyed with paper
the help of microbial inoculants. Tooth paste Pigments
(14) Bioinsecticides. Xanthan gum
Textile Fertilizers
Ans.
pigments
(i) Bacterial and fungal toxins which can destroy .
Weedicides
pests and pathogens can be directly integrated
into plants with the help of biotechnology. *(3) Complete the following conceptual picture
(ii) Insects do not consume such plants, as they are related to environment management.
toxic to insects. Ans. Oil Spills Decompose
(iii) Similar to bacteria, some species of fungi and Microbial
PET, Rubber
inoculants
viruses are useful as pesticides. Microbes
(iv) Spinosad, a by-product of fermentation is a Biopesticides Sewage
biopesticide. Bio-fuel

Q.2.5 Distinguish between:

(1) Yoghurt and Cheese

Ans. Yoghurt Cheese

(i) Milk product produced with the help of (i) Milk product produced with the help
Streptococcus thermophilus, Lactobacillus delbrueckii of Lactobacillus lactis, Lactobacillus cremoris
Streptococcus thermophilus.
(ii) Only bacterial fermentation is required. (ii) Bacterial and fungi both microbes are required.

(2) Chemical catalyst and Microbial enzymes

Ans. Chemical catalyst Microbial enzymes

(i) Catalysts are active at high temperature, pressure. (i) Enzymes are active at low temperature, pH
pressure.

(ii) Large amount of energy is required. (ii) Energy is saved and erosion proof instruments
are also not necessary.
140 Master Key Science and Technology Part-2 (Std. X)

Q.2.6. Give scientific reasons: Q.3.1. Question based on any incident:

(1) Milk is pasteurized at the beginning. (1) Priya’s mother has left for office, asking her to
Ans. set curds for the meals, suggest ways in which
(i) Milk is converted into various products for its Priya will set curds.
preservation purpose. Ans.
(ii) Milk is pasteurized at the beginning to destroy (i) Priya will take some milk in a bowl.
unwanted microbes.
(ii) Heat the milk and allow it to cool.
(2) Whey is removed during cheese production.
Ans. (iii) To the warm milk spoonful of curd is added. and
stirred.
(i) Whey (water in yoghurt) is removed during
cheese production to impart dense texture to (iv) It is allowed to stand for sometime i.e. 5-6 hrs to
cheese. get fresh curd.
*(3) Microbial enzymes are used instead of chemical (v) The fresh curd is moved to the refrigerator.
catalysts in chemical industry. (2) Suresh is down with diarrhoea. Suggest food
Ans. that can help him with his stomach trouble.
(i) Microbial enzymes are active at low temperature, Ans.
pH and pressure, due to which energy is saved (i) Suresh can eat fresh yoghurt.
and erosion - proof instruments are also not (ii) It is a probiotic which contains active bacteria.
necessary. e.g. Lactobacillus.
(ii) Enzymes carry out specific processes, hence (iii) These microbes maintain the balance of intestinal
unnecessary by-products are not formed due microorganisms.
which expenses on purification are minimised.
(iv) They increase the population of microbes helping
(iii) Elimination and decomposition of waste the digestion and decrease the population of
materials is avoided and enzymes can be reused. harmful microorganisms e.g. Clostridium.
Such enzymes are eco-friendly.
(3) Swati was suffering with Tuberculosis. She
(iv) Therefore microbial enzymes are used instead of
was advised a course on antibiotics. Suggest
chemical catalysts in chemical industry.
methods by which swati can improve her health
*(4)  Enzymes obtained by microbial process are by her food.
mixed with detergents. Ans.
Ans. (i) A strong and heavy course of antibiotics will
(i) Enzymes obtained by microbial process are active inactivate useful microbes in her intestine.
at low temperature, pH and pressure.
(ii) Probiotic milk products like yoghurt, dark
(ii) Hence enzymes mixed with detergents help in chocolate, kefir, miso soup, pickles will activate
process of dirt/muck removal even at low her intestinal useful microbes again.
temperature.
(iii) They will also improve her resistance.
*(5)  Use of mutant strains has been increased in
(4) Bhikaji Tambe a farmer in Kolhapur has
industrial microbiology.
planned a big harvest of sugarcane in his field.
Ans.
Suggest him ways and means for a high yield
(i) Use of microbes to obtain a product which is
with organic farming.
cheaper is now a trend is industrial Microbiology.
Ans.
Mutant strains are genetically improved strains
(i) Bhikaji Tambe can add solution of Azotobacter
which give higher yields and therefore decrease
and artificial nitrogenase to get good quality
the cost of the products.
sugarcane and a high yeld also.
(ii) Mutant strains are formed by alterations of
(ii) Use of bioinsecticides will also help in good
nucleotides is DNA of micro organisms to suit
harvest.
the needs of the industry.
Q.3.2. Complete the paragraph:
(iii) Mutant strains are used for producing virus
resistant bacterial strains are used in Dairy (1) Compressed waste is in the pit. It is
industry (milk products) so as to avoid the covered with layers of , , leafy
unwanted bacteria and virues attacking and out waste and . are mixed at some
membering the original ones. places. present in the soil and other top
layers the waste. Completely filled pit
(iv) In alcohol industry mutant strains improve the
is with soil , Best quality is
flavour and quality of wine or beer.
formed after few days.
Introduction to Microbiology 141

Choose the correct alternative from below. (4) Enlist the sources of various organic acids, the
(compost, microbes, saw dust, slurry sealed, soil, microbes used to produce them and their uses.
dumped, bioreactors, biochemicals, decompose) Ans.
Ans. Compressed waste is dumped in the pit. It is Source Microbe Amino acid Use
covered with layers of soil , sawdust , leafy waste
and biochemicals . Bioreactors are mixed at some Sugar and Brevibacterium, L-glutamic Production
beet Corynobacterium acid of monoso-
places. Microbes present in the soil and other
molasses, dium
top layers decompose the waste. Completely ammonia glutamate
filled pit is sealed with soil slurry. Best quality salt (Ajinomoto)
compost is formed after few days.
Sugar Aspergillus niger Citric acid Drinks,
Q.3.3. Complete the table: molasses, toffees,
(1) salt chocolate
Fruit Microbe used Role of Name of production
Microbe beverage Glucose, Aspergillus niger Gluconic Production
1. Theobroma Candida, Separating Cocoa corn steep acid of minerals
cacao Hansenula seeds from liquor used as
fruit supplement
for calcium
2. Apple Saccharomyces Fermen- Cider
and iron
cerevisiae tation of
juice Molasses, Lactobacillus Lactic acid Source of
corn steep delbrueckii nitrogen,
(2)
liquor production
Substances obtained by of vitamins.
microbial processing Roles
Molasses, Aspergillus Itaconic acid Paper,
(1) Glutamic acid, (a) Protein binding corn steep itaconius textile,
Tryptophan, Lysine liquor plastic
(2) Polysaccharides, (b) Emulsifiers industry,
glycolipids gum
(3) Lutein, Xanthenes, (c) Edible colors production
betacarotene
Q.3.4. Figure based Question:
(4) Xylitol, aspartame (d) Artificial sweetner
(low calorie) (1) Observe the following diagram and answer the
(3) Enlist different microbes and their role in questions:
production of beverages.
Ans. Solar energy + CO2
Biomass
Sr. Microbe used Role of Name of
Fruit Harvesting
No. microbe beverage Conversion
of cellulose to
1. Caffea Lactobacillus Separating glucose
arabica brevis seeds from Coffee Threshing
fruit
2. Theobroma Candida, Separating Cellulose
CO2
Sugar
cacao Hansenula, seeds from
Pichia, fruit Cocoa CO2

Saccharomyces CO2

3. Grapes Saccharomyces Fermenta- CO2

Wine
cerevisiae tion of juice Liquid fuel
production
Apple Saccharomyces Fermenta- through fermentation.
4. Cider
cerevisiae tion of juice Fig. 7.1 Biofuel Production
142 Master Key Science and Technology Part-2 (Std. X)

(i) Solar energy + CO2 contributes to which (B) Which precautions should be taken about
process? their consumption? (Can you recall; Textbook
Ans. Photosynthesis Page no. 82)
Ans.
(ii) What is biomass?
(i) Antibiotics should be taken only when prescribed
Ans. Biomass is organic matter used to produce fuel. by a doctor.
(iii) Who helps in the conversion of cellulose to (ii) Don’t purchase any antibiotic from medical stores
glucose? without a prescription from a doctor.
Ans. Enzymes. (iii) Don’t consume antibiotics on your own to treat
(iv) Name the liquid fuel produced through common diseases like a throat infection, common
Fermentation. cold or influenza.
Ans. Ethanol. (iv) Even if you feel well before completing of the
prescribed course of the antibiotic, you must
(v) Classify the fuels.
continue and complete it.
Ans. Solid fuel, Liquid fuel, Gaseous fuel. (v) Don’t suggest to others the antibiotics which
(vi) Who ferments sugar into liquid fuel? were useful to you.
Ans. Microbes. *(3) Observe the garbage vans of grampanchayat
Q.3.5. Answer the following: and municipality. Nowaday, there is facility of
decreasing the volume of garbage by compaction
*(1) Which type of cheese is used in western food
in those vans. Explain the advantages of this
like pizza, burger, sandwich, etc?
activity. (Observe; Textbook Page no. 83)
What is the difference between those types of
Ans.
cheese. (Lets think; Textbook Page no. 78)
(i) Waste compaction is the process of compacting
Ans.
waste, reducing it in size.
(i) Cheese used in pizza are - mozzarella, provolone, (ii) Garbage compactors and waste collection
cheddar and Parmesan. vehicles compress waste so that more of it can be
(ii) Cheese used in burger is cheddar. stored in the same space.
(iii) Cheese used in sandwich - Mozzarella, Cheddar. Advantage of compaction of garbage:
(i) Compacted waste means less trips to the landfill
(iv) Mozzarella is a softer, Italian cheese that has a
are needed.
subtle taste. Its not aged for long.
(ii) This is a more eco-friendly solution to waste
(v) White cheddar is a hard type of cheese that removal. Fewer trips to the landfills will reduce
usually has a more pungent or sharp flavour. Its transportation costs and the pollution or
origin is Somerset, England and is aged for 12 - 16 emissions created from those trips.
months. Yellowish whitish in colour and usually (iii) Reduces insect and rodent problems.
crumbly in texture. Its hard, sharp tasting cheese
(iv) Controls odour.
best used in grilled cheese sandwiches.
*(4) You must have seen or read the news of dead
(vi) Provolone is a semi-hard Italian cheese which fishes or oily water accumulating at the sea
is blended with Mozzarella. The flavour of coasts. Why does this happen? (Can you tell;
provolone varies greatly depending on how long Textbook Page no. 84)
its been aged. Ans.
(vii) Parmesan cheese is aged 3-8 months which makes (i) This happens due to oil spills.
it a bit hard in texture. Made from cow’s milk it
(ii) An oil spill is the release of a liquid petroleum
has its origin in Italy and is granular in nature. hydrocarbon into the environment especially the
*(2) (A) What do you mean by antibiotic? (Can you marine ecosystem, due to human activity and is a
recall; Textbook Page no. 82) form of pollution.
Ans. Carbon compounds obtained from some bacteria (iii) Oil spills may be due to release of crude oil
and fungi for destroying or preventing the from tankers, offshore platforms, drilling rigs
growth of harmful micro-organisms are called and wells, as well as spills of refined petroleum
antibiotics. product.
Introduction to Microbiology 143

*(5) Explain the importance of biopesticides in (i) Lactobacilli is used for Yoghurt production.
organic farming. (ii) Yeast - Saccharomyces cerevisiae is used for vinegar
Ans. and bread production.
(i) Fluoroacetamide-like chemicals are mixed (iii) Acidophilus, Lactobacillus casei, Bifidobacterium
with soil due to use of chemical pesticides in bifidum are probiotic microbes.
agriculture. (iv) Acetobacter, Glucanobacter is mixed for microbial
(ii) These prove to be harmful to other plants and degradation of ethanol.
animals as well as cause skin disease to humans. *(9) Which different products can be produced with
Therefore biopesticides are used nowadays. the help of microbes? (Can you recall; Textbook
(iii) Bacterial and fungal toxins which can destroy Page no. 77)
pests and pathogens can be directly integrated Ans.
into plants with the help of biotechnology. (i) Products produced with the help of microbes are
(iv) Being toxic to insects, plants are saved from them. bread, cheese, wine, yoghurt, butter, probiotics
(v) Spinosad, is a biopesticide. It is a by-product of and vinegar.
fermentation. (ii) They are also used for producing chemicals,
*(6) Which are the reasons for increasing the enzymes, nutrients, medicines like antibiotics
popularity of probiotic products? and also for Bio-fuel.
Ans. (iii) They are used in garbage management and
(i) Probiotics are milk products containing active pollution control.
bacteria. *(10) We use the fermentation process while
(ii) These microbes maintain the balance of intestinal conversion of milk into Yoghurt. Which
organisms. microbes are useful for this process? (Can you
recall; Textbook Page no. 77)
(iii) These products form the colonies of useful
microbes in alimentary canal and control other Ans.
microbes and their metabolic activities, improve (i) Milk is fermented with the help of Lactobacilli.
resistance and lower the effects of harmful (ii) Bacterial strains of Streptococcus thermophilus and
substances formed during metabolic activities. Lactobacillus delbrueckii are added to warm milk in
(iv) Useful microbes become inactive due to 1:1 proportion.
antibiotics, probiotics make them active again. *(11) How does the bread become spongy? OR How
(v) Nowadays, probiotics are used for treatment of is bread produced?
diarrhoea and treatment of poultry also. Ans.
*(7) How the bread and other products produced (i) Different types of breads are produced from flour
of cereal.
using baker’s yeast are nutritious?
(ii) Dough for bread is formed by mixing of baker’s
Ans.
yeast - Saccharomyces cerevisiae, water, salt and
(i) Compressed yeast is used in commercial bakery other necessary materials with flour.
industry.
(iii) Due to fermentation of carbohydrates by yeast,
(ii) It is available in dry, granular form for domestic sugar is converted into carbon-dioxide (CO2) and
use. ethanol (C2H5OH).
(iii) Yeast produced for commercial use contains (iv) Dough rises up due to CO2 and the bread becomes
various useful contents like carbohydrates, fats, spongy.
proteins, various vitamins and minerals.
(12) Explain the production of cheese.
(iv) Due to this, bread and other products produced
Ans.
with the help of yeast become nutritive.
(i) Abundantly available cow’s milk is used for large
*(8) Which different microbes are useful to us? (Can scale production of cheese.
you recall; Textbook Page no. 77)
(ii) Chemical and microbiological tests of milk are
Ans. performed first.
144 Master Key Science and Technology Part-2 (Std. X)

(iii) Colours and some microbes like Lactobacillus about the reaction of carbon with oxygen. CO2
lactis, Lactobacillus cremoris and Streptococcus and water is formed in the process.
thermophilus are mixed with milk to impart (17) What are the different types of cheese?
sourness. Ans.
(iv) Whey (water in yoghurt) is removed to impart (i) Freshly prepared cheese is always soft. eg.
dense texture. Cottage cheese, cream cheese, mozzarella cheese.
(v) Enzyme protease obtained from fungi is used to (ii) On storing for 3 to 12 months, semi-hard cheddar
produce vegetarian cheese. cheese is formed.
(vi) The solid yoghurt is cut into pieces, washed, (iii) After ripening for 12 - 18 months, very hard
rubbed, salted and mixed with essential microbes, cheese called parmesan cheese is formed.
pigments and flavours. *(18) Why it is necessary to ban the use of plastic
(vii) Cheese is pressed and cut into pieces and stored bags?
for ripening. Ans.
(13) Explain the role of microbes in farming. (i) Plastic bags pollute our land and water resources.
(ii) Plastic bags do not degrade easily.
Ans.
(iii) Plastic bags are harmful to wild life, marine and
(i) Microbes containing inoculants help in plant
human health. Hence, plastic bags should be
growth by supplying nutrients.
banned.
(ii) Solution containing Azotobacter and artificial
*(19) How can the soil polluted by acid rain be made
nitrogenase is used in organic farming.
fertile again?
(iii) Pesticides like Fluoracetamide can be destroyed Ans.
with the help of microbes. (i) Sulphuric acid is present in the acid rain and in
(iv) Spinosad, a by-product of fermentation is a materials coming out of mines.
bio-pesticide. (ii) Erosion of bridges, metal statues, occurs due to
*(14) Which precautions are necessary for proper acid rain.
decomposition of domestic waste? (iii) Sulphuric acid is the source of energy for some
Ans. species of bacteria like Acidophillium spp. and
(i) Segregation of waste - waste has to be segregated Acidobacillus ferroxidens.
into dry and wet and accordingly headed for (iv) Hence, these bacteria can control the soil
disposal. pollution occurring due to acid rain, and the soil
(ii) Dry wastes need to be sent for recycling. can be made fertile again.
(iii) Wet wastes need to be sent to land-filling sites for Q.4.1. Answer in detail.
composting. (1) Describe in brief Biofuel production with the
help of a neat labeled diagram.
*(15) What are the benefits of mixing ethanol with
petrol and diesel? Ans.
Ans. (i) Biofuel is important among the renewable source
(i) Ethanol is a renewable, domestically produced of good energy.
transportation fuel. (ii) Biofuel is produced by plants by photosynthesis
where Carbohydrates and Oxygen is prepared
(ii) It burns more cleanly producing less carbon
using Solar energy.
emission.
(iii) These fuels are available is solid (Coal, dung, crop
(iii) Reduces dependence of fossil fuels.
residue), liquid (Vegetable oils, alcohol), gaseous
(iv) Enhances the octane content in the fuel. (gobar gas, Coal gas) forms.
*(16) How can the oil spills of rivers and oceans be (iv) For biofuel production, biomass is harvested and
cleaned? transported for threshing. Later the cellulose ob-
Ans. tained from the residues left after threshing is
(i) Bacteria like Pseudomonas spp. and Alcanovorax converted to glucose.
borkumensis have the ability to destroy the (v) The glucose is further converted to liquid fuel
pyridines and other chemicals. through fermentation, which is used for various
(ii) Hence, these bacteria are used to clear the oil spills. purposes.
(iii) These are called as Hydrocarbonoclastic bacteria (vi) CO2 released during the burning of these biofuel
(HCB). which is again absorbed by plants for photosyn-
thesis.
(iv) HCB decompose the hydrocarbons and bring
Introduction to Microbiology 145

(2) Complete the flow chart and answer the domestic waste, agricultural waste, etc. Hence,
questions given below: their cost of production is relatively very high.
(a) (iv) When methane is burned, comparatively lower
Dairy Products amounts of smog forming pollutatnts, toxic air
and gases are generated.
(v) Ethanol is a clean fuel. It is obtained during
Yoghurt Butter Cheese Probiotics
fermentation of molasses by Saccharomyces.
(vi) Hydrogen gas is considered as the fuel of future
Bacteria Bacteria Bacteria Bacteria since it does not emit any harmful substances
Fung on buring and is produced by bio-photolysis of
water.
(b) What is the basic purpose behind conversion of
milk into various dairy products? (vii) As a result, it is necessary to increase the use of
fuels obtained by microbial processes.
Ans. To preserve milk
Types:
(c) Give example of one microbe used in any two
of the above dairy products. (i) Ethanol-biologically produced alcohols, most
commonly ethanol and less commonly propanol
Ans. Streptococcus thermophilus is used in both yoghurt and butanol are produced by the action of micro-
and cheese production. organisms and enzymes through the fermentation
(3) Explain the role of microbes in chemical of sugar or starch cellulose.
pollution. (ii) Bibutanol also called biogasoline is often claimed
Ans. to provide a direct replacement for gasoline.
(i) Some microbes remove the sulphur from fuels. Biogas is methane produced by the process
(ii) Metals like copper, iron, uranium, zinc, etc. of anaerobic digestion of organic material by
leach into environment from low quality anerobea.
metalloids. These are converted into compounds *(5) What is role of microbes in compost production?
before leaching with the help of Thiobacilli and Ans. All biodegradable waste can be converted into
Sulphobacilli. compost.
(iii) Bacteria like Pseudomonas spp and Alcanovorax (i) Bacteria, fungi and actinomycetes are the
borkumensis have ability to destroy the pyridines microbes that decompose the organic matter.
and other chemicals. Hence, these bacteria are (ii) Aerobic bacteria are the most important ones.
used to clear oil spills. (iii) Microbes break down the organic matter and
(iv) Species like Vibrio, Ideonella sakaiensis decompose produce carbon dioxide, water, heat and humus
PET (Polyethylene Terephthalate Polyester). which makes it very nutritious.
(v) Species of fungi like Actinomycetes, Streptomyces, (iv) They provide the most rapid and effective
Nocardia, Actinoplanes have the ability to composting.
decompose rubber from garbage. (v) Their excreta contains plant nutrients such as
(vi) Bacteria like Acidophillium spp. and Acidobacillus nitrogen, phosphorus and magnesium.
ferroxidens control the soil pollution occurring (vi) Actinomycetes are responsible for the earthy smell
due to acid rain. of the compost.
(vii) Geobacter convert water soluble salts of uranium (vii) They decompose cellulose, starches and proteins
into insoluble salts and hence prevent these salts liberating carbon, nitrogen and ammonia in the
from mixing with ground water sources. process, which are useful for higher plants.
*(4) Which fuels can be obtained by microbial (viii) Fungi breakdown cellulose and lignin and take
processes? Why is it necessary to increase the over the final stage of composting.
use of such fuels? (ix) Thus microbes help in recycling the nutrients
Ans. through composting.
(i) Various fuels like methane, ethanol, hydrogen (5) Explain the process of Land - filling site with a
gas, etc. are fuels obtained by microbial processes. neet labelled diagram.
(ii) It is necessary to increase the usage of such fuels Ans.
so as to reduce exhaustion of fossil fuel resources. (i) Degradable waste being accumulated in urban
(iii) Most of thse fuels can be obtained by anaceobic areas is used for this purpose.
decomposition of waste products such as (ii) Large pits are dug in open spaces far away from
146 Master Key Science and Technology Part-2 (Std. X)

the residential area and those pits are lined with (vi) A by-product of sewage treatment is usually a
plastic sheets as a precaution against pollution semi-solid waster or slurry called sewage sludge.
of soil due to leaching of toxic and harmful The sludge has to undergo further treatment
materials. before being suitable for disposal or application
(iii) Compressed waste is dumped in the pit. It is to land.
covered with layers of soil, saw dust, leafy waste (vii) The first part of filtration of sewage typically
and specific biochemicals. includes a bar screen to filter solids and large
(iv) Bioreactors are mixed at some places. objects which are then collected in dumpsters
(v) Microbes present in soil and other top layers and disposed in landfills.
decompose the waste.
(vii) The second part removes dissolved and
(vi) Completely filled pit is sealed with soil slurry. suspended biological matter. The secondary
(vii) Best quality compost is formed after few days. treatment is typically performed by indigenous
(viii) Such land filling sites can be reused after removal water borne micro-organisms in a managed
of compost. habitat.
(viii) Tertiary / third part is ejection into a highly
Methane Processing on sensitive ecosystem. Treated water is sometimes
Gas Soil
Garbage sewage disinfected chemically or physically prior to
cover
discharge into a stream, lagoon etc. It can be used
for ground water recharge as it is sufficiently
well to clean.
monitor Q.4.2 Paragraph based questions
ground
water Read the paragraph and answer the following
level Collection of sewage questions:

In cities sewage needs to be carried to

processing unit and acted upon by microbial
Fig. 7.2 Modern landfill site process. Microbes which can decompose any
compound as well as destroy the pathogens
*(6) How the sewage generated in your house or
of cholera, typhoid are mixed with sewage.
apartment is disposed off ? (Collect information;
They release methane and carbondioxide
Textbook Page no. 84) by decomposition of the carbon compounds
Ans. present in sewage. Phenol oxidising bacteria
(i) Sewage or domestic wastewater or municipal decompose the xenobiotic chemicals present
waste water that is produced from a community in sewage.
of people.
(ii) It consist mainly of grey water from sinks, tubs, (1) Where is sewage in cities disposed off?
showers, dish washers and clothes washers, black Ans. In cities sewage needs to be carried to processing
water - the water used to flush toilets combines unit and acted upon by microbial process.
with human waster, soaps, detergents, toilet (2) Which disease pathogens are destroyed by
paper, etc. microbes?
(iii) Sewage usually travels from a buildings Ans. Microbes can destroy pathogens of Cholera and
plumbing either into a sewer, which will carry it Typhoid.
elsewhere or into an onsite sewage facility. (3) Which gases are released by decomposition of
(iv) In many developing countries the bulk of carbon compounds?
domestic and industrial wastewater is discharged Ans. Methane and Carbon-dioxide are released by the
without any treatment or after primary treatment decomposition of carbon compounds.
only. (4) What is the role of Phenol oxidising bacteria?
(v) In the primary treatment the process of Ans. Phenol oxidising bacteria decompose the
removing contaminants from wastewater and Xenobiotic chemicals present in sewage.
produce treated wastewater that is safer for the (5) Give a heading to the paragraph.
environment. Ans. Sewage Management in cities.

vvv
Introduction to Microbiology 147

ASSIGNMENT - 7
Time : 1 hour Marks : 20

Q.1.(A) Answer the following: (3)

(1) Fill in the blanks: Acetic acid is bleached with the help of .................. .
(2) Find the odd man out: Penicillin, erythromycin, gentomycin, acetic acid
(3) Complete the analogy: Yoghurt : Bacteria :: Cheese : ..................
Q.1(B) Choose and write the correct option. (2)
(1) Most appropriate method of disposal of dry waste is .................. .
(a) sanitary landfill (b) composting (c) incineration (d) recycling
(2) bacteria present in root nodules of leguminous plants help in nitrogen fixation.
(a) Rhizobium (b) Azotobacter (c) Geobacter (d) Pseudomonas
Q.2.Answer the following. (Any 2) (4)
(1) Write a note on importance of probiotics.
(2) Complete the chart.
Fermentation of carbon compounds
Yeast Saccharomyces cerevisiae

Microbial degradation Acetobacter + Glucanobacter

Bleaching Potassium ferrocynide

(3) Give scientific reason: Milk is pasteurized at the beginning.

Q.3.Answer the following (Any 2) (6)

(1) Source Microbe Use

(1) Sugar Molasses _______________ Production of Monosodium glutamate

(2) Sugar Molasses and salt A spergillus niger ____________________________

(3) Glucose and corn steep liquor A spergillus niger ____________________________

(4) Molasses and corn steep liquor _______________ Production of Vitamins

(2) What is the role of microbes in compost production?

(3) Explain the importance of biopesticides in organic farming.
(4) Write a short note on Xanthan gum.
Q.4.Answer in detail (Any 1) (5)
(1) Explain in detail Biofuel production with a neat labelled diagram.
(2) Describe the process of Land filling site with a neat labelled diagram.
vvv
 8
BIOTECHNOLOGY

Human health Agriculture Food production Environment Molecular Animal husbandry

biotechnology
Hormones Hybrid seeds Cheese Fuel

Vaccines Biofertilizers Wine Solid waste

management Artificial Embryo
Cloning DNA Insemination transfer
Antibiotics Genetically Bread
modified crops finger
Bioremediation printing
Interferons Vinegar

(148)
Medicines
Yoghurt
Reproductive Therapeutic
Gene therapy Bt crops Herbicide cloning cloning
CONCEPT MAP

tolerant plant

Nutrient
rich plants

Green White Blue

Revolution Revolution Revolution
Cell Biology and Biotechnology

Grain and Milk Fish

crops and milk
products
Cell Biology and Biotechnology 149

(2)
Important Stages in Agricultural Development

(1) (2) (3) (4)

Green Revolution White Revolution Blue Revolution Growing crop plants

fertilizers organic
and chemical
Improved Newer dairy Production of
varieties of products and their shrimps and lobsters
wheat, rice etc. preservation cultured on large
scale

Insecticides Organic farming Apiculture Cultivation of Fruit processing

medicinal plants

(3) Stem Cell Research

Cell therapy
Regenerative
therapy
Stem cells Production of
Organ
transplantation blood cells

Embryonic stem cells Adult Stem Cells

Neurons
Division of zygote 3 sources
(brain)
Formation of an embryo
Osteocytes
Repeated mitotic divisions (bone)
Red bone Adipose Blood
Cell Differentiation marrow connective tissue
14th day of conception Hepatocytes
(liver)

Pleuripotency Self multiplying ability Cardiac

cells (heart)

Columnar
Transformation into cells epithelium (Intestine)

Tissues

Organs
150 Master Key Science and Technology Part-2 (Std. X)

(4)
ORGAN DONATION

After Death Before Death

Ligaments A part of the lung

and liver
Bones
A part of intestine
Liver
A Kidney
Pancreas

Small intestine

Kidneys

Skin

Heart

Lungs

Points to Remember:
zz Cytology / Cell Biology - Study of the structure, types, organelles of the cell, cell division, etc.
zz Research Institute dedicated for research on cells :
- National Centre for Cell Science is located in Pune.
- Instem is located in Bengaluru.
zz Stem cells are special cells present in the body of multicellular organisms, which give rise to all other types
of cells present in the body
zz Stem cells are found in umbilical cord, red bone marrow and adipose connective tissue.
zz Cell differentiation start on 14th day of conception.
zz Osteocytes, hepatocytes, neurons are formed due to differentiation.
zz Uses of stem cell.
- Regenerative therapy includes cell therapy in which stem cells are used to replace dead cells in case of
conditions like diabetes, myocardial infarction, Alzeheimer’s disease and Parkinson’s disease.
- It is also used to produce blood cells in conditions like anemia, thalassaemia and leukemia.
- Organ transplantation : organs like kidney, liver can be produced with the help of stem cells and
transplantation takes place only when there is a donor available.
- Various factors like blood group, diseases and disorders, age etc are first considered during transplantation.
zz Some organs can be donated during life time and some can be donated after death (posthumous).
Cell Biology and Biotechnology 151

zz Body and organ donation can save life of needy individuals.

zz Biotechnology is bringing artificial genetic changes and hybridization in organisms for human welfare.
zz Biotechnology includes following areas: Use of microbes for Yoghurt formation from milk and alcohol from
molasses.
- Production of antibiotics and vaccines with help of specific cells.
- Use of Bio - molecules like DNA and proteins in human welfare.
- Gene manipulation helps in development of desired plant, animals and products.
- Genetically modified bacteria is used for production of human growth hormone .
- Use of genetic and non - genetic technique for tissue culture and production of hybrid seeds.
zz Benefits of Biotechnology
- Increase in per hectare yield of crop-land has become possible.
- Expenses on disease control have minimized since development of resistant varieties.
- Development of fast fruit setting varieties and their yield per annum.
- Development of stress resistant varieties which can withstand variable temperature, water-stress,
changing fertility of soil, etc.
zz Commercial applications of Biotechnology
- Crop Biotechnology is used in agricultural field to improve yield and variety.
- Hybrid seeds and Genetically modified crops are developments of crop biotechnology.
- Bt Cotton, Golden Rice, Herbicide tolerant plants and Biofertilizers are examples of development in
crop biotechnology.
zz Biotechnology has made advances in Animal husbandry. Two main methods as artificial insemination and
embryo transfer have helped to improve both quantity and quality of animal products.
zz Biotechnology helps in diagnosis and treatment of diseases at an early stage. Various vaccines and
antibiotics are produced.
- Traditionally vaccines were prepared with help of pathogens which were completely or partially killed.
Due to this, there were chances of infection.
- Therefore, artificial vaccines were produced by using antigen with the help of gene isolated from the
pathogen and sometimes proteins were used which acted as antigen.
- Vaccines produced with the help of biotechnology are more thermostable and remain active for longer
duration.
- Edible Vaccines are in progress and presently potatoes are being produced with help of biotechnology.
They are called as Transgenic Potatoes.
- Consumption of these potatoes generates immunity against bacteria like Vibrio cholerae and Escherichia
coli and disease caused by them.
- Biotechnology is useful in production of hormones like insulin, somatotropin and blood clotting
factors.
- Interferon, a small sized protein molecule is used in treatment of viral diseases.
- Gene therapy which is used to treat genetic disorders in somatic cells has become possible due to
biotechnology.
- Cloning: Production of replica of any cell or organ or entire organism. It has been possible due to
development in biotechnology.
- Reproductive cloning and therapeutic cloning are the processes used for cloning.
zz Various industrial chemicals can be produced through less expensive processes. e.g. Alcohol production
from sugar molasses.
152 Master Key Science and Technology Part-2 (Std. X)

zz Biotechnology has helped to solve environment related problems. e.g. Microbial decomposition of waste.
zz Bio-remediation, biopesticides, biofertilizers etc. are the new concepts in biotechnology.
zz Food items like bread, cheese, wine, beer, yoghurt are oldest items produced with the help of biotechnology.
zz DNA fingerprinting is one of the most important developments in biotechnology which has found
application in Forensic Science.
zz All the research work is done in Centre for DNA fingerprinting and Diagnostics, Hyderabad.
zz Green Revolution is an important stage in agricultural development.
zz Dr. Norman Borlaug (USA) and Dr. M.S. Swaminathan (India) have valuable contribution in green
Revolution.
zz White Revolution was led by Dr. Verghese Kurien in various parts of India which were rich in milk and
milk products.
zz Government launched Nil-Kranti Mission in 2016 to promote pisciculture. This was termed as Blue
Revolution.
zz Organic manure and chemical fertilizers are used as fertilizers
zz Use of insectides should be reduced as they enter food-web through nature and food and its bio-
magnification occurs.
zz DDT, malathion and chloropyriphos have been proved dangerous.
zz Organic farming and organic products are available now which can prevent the harmful effects of fertilizers.
zz Apiculture is culturing of bee for honey and wax.
zz India, has a great tradition of ayurveda that cures many diseases. Therefore, medicinal plants are cultivated.
zz Fruits are perishable agro-products : They can be preserved by cold storage, drying, salting, air tight
packaging, preparing murabba and evaporating.

*(9) Government of India has encouraged the

MASTER KEY QUESTION SET - 8
for improving the productivity by
Q.1. (A) 1. Fill in the blanks and rewrite the launching NKM - 16.
completed statements: *(10) is the revolutionary event in
biotechnology after cloning.
(1) Cells of the embryo undergo repeated
*(11) Methods like artificial insemination and embryo
division.
transplant are mainly used for .
(2) Availability of is an important
*(12) The disease related with the synthesis of insulin
requirement in organ transplantation.
is .
(3) All the cells except sperm and ova in the body are (13) play an important role in wound
called as cells. healing.
(4) Alcohol is produced from sugar molasses with (14) The mass of cells at the earliest stage of
the help of yeast. development are called .
(5) The bacteria are useful for cleaning (15) Stem cells are present in the by
the hydrocarbon and oil pollutants from soil and which the foetus is joined to the uterus of the
water. mother.
(6) Sunflower can absorb and arsenic. (16) Stem cells are present in and
of adult human being.
(7) Water holding capacity of the soil improves with
(17) Stem cell vials are stored in at –135 0C
soil conservation due to use of .
to –190 0C.
(8) We have great tradition of that cures
(18) The property of self-multiplying of stem cells is
the diseases with the help of natural sources. called as .
Cell Biology and Biotechnology 153

(19) Bringing about artifical genetic changes and Q.1. (A) 2. Find the odd word out:
hybridization in organisms for human welfare is (1) Cord blood, red bone marrow, epithelial tissue,
called . adipose connective tissue.
(20) Crops developed with desired characters by Ans. Epithelial tissue - They are tissues present in
integrating foreign gene with their genome are surface of skin, cover of internal organs. Others
called as crops. are sources of stem cells.
(21) Bt cotton and Bt brinjal are developed by using (2) Liver, heart, eyes, kidney.
gene isolated from . Ans. Kidney - It can be donated during life time. Other
(22) A gene synthesizing has been organs can be donated after death only.
introduced in Golden Rice. (3) Cytology, molecular biology, genetic engineering,
(23) is the antigen containing material cosmology.
given to acquire immunity. Ans. Cosmology - It is study of the universe. Others
are sciences included in biotechnology.
(24) Potatoes which can be used as edible vaccines are
called . (4) Rhizobium, Azotobacter, Nostoc, Lactobacilli.

(25) is used is the treatment of viral Ans. Lactobacilli - It is a bacteria present in milk. Others
diseases. are biofertilizers.
(5) Alfalfa, rye, clover, bamboo.
(26) arises due to genetic changes in
hepatocytes (liver cells). Ans. Bamboo - Others are grasses used for
phyto-remediation.
(27) Production of replica of any cell or organ or entire
organism is called . (6) Somatostatin, erythropoietin, interleukin,
phenylketonuria.
(28) The fern can absorb arsenic from the
Ans. Phenylketonuria - It is a genetic disorder - Others
soil.
are proteins to treat various disorders.
(29) The bacterium is highly radiation
(7) DDT, malathion, chloropyriphos, NPK.
resistant organism.
Ans. NPK - These are essential elements. Others are
(30) Grasses like alfalfa, clover and rye are used for
names of pesticides.
.
Q.1. (A) 3. Considering the relationship in the first
(31) discovered microbes for cleaning
pair, complete the second pair and rewrite:
the oil spills.
(1) National Centre for Science : : Pune : Instem : :
(32) Production of various useful organisms with the
.
help of water is called as revolution.
Ans. Bengaluru - The National Centre for Cell Science
(33) Cell differentiation starts from day is established at Pune and ‘Instem’ is established
of conception. at Bengaluru.
(1) mitotic (2) donor (3) somatic (4) transgenic
Ans.  (2) Green revolution : Dr. M. S. Swaminathan
(5) Pseudomonas (6) Uranium (7) manures and Dr. Norman Borlaug : : White revolution :
(8) ayurveda (9) pisciculture (10) Stem cell .
research (11) animal husbandry (12) Diabetes Ans. Dr. Verghese Kurien - Dr. M.S. Swaminathan and
(13) Stem cells (14) Stem cells (15) umbilical Dr. Norman Borlaug have valuable contribution
cord (16) red bone marrow, adipose connective in Green Revolution, whereas Dr. Verghese
tissue (17) liquid nitrogen (18) pleuripotency Kurien has contributed in white revolution.
(19) biotechnology (20) genetically modified (3) National Pomegranate Research Institute :
(21) Bacillus thuringiensis (22) Vitamin A (beta Solapur : : National Citrus Research Institute :
carotene) (23) Vaccine (24) transgenic potatoes
(25) Interferon (26) Phenylketonuria (27) cloning Ans. Nagpur - National Pomegranate Research
(28) Pteris vitata (29) Deinococcus radiodurans Institute is established in Solapur, whereas
(30) phyto-remediation (31) Dr. Anand Mohan National Citrus Research Institute is established
Chakravarti (32) blue (33) 14th. in Nagpur.
154 Master Key Science and Technology Part-2 (Std. X)

*(4) White revolution : Dairy : : Blue revolution :

(2) Column ‘A’ Column ‘B’
.
(1) Bt Brinjal (a) Azotobacter
Ans. Aquatic organisms - White revolution involves
improved production of dairy and dairy products (2) Weeds (b) Bacillus thuringiensis
whereas, Blue revolution involves improved (3) Golden Rice (c) Herbicides
production of Aquatic organisms.
(4) Biofertilizer (d) Vitamin A
*(5) Insulin : Diabetes : : Interleukin : .
Ans. Cancer - Insulin is used to treat diabetes, whereas (e) Hybrid seeds
Interleukin is used to treat cancer. Ans. (1 - b), (2 - c), (3 - d), (4 - a)
*(6) Interferon : :: Erythropoietin: (3) Column ‘A’ Column ‘B’
Anemia.
(1) Dr. Anand Mohan (a) Green
Ans. Viral Infection - Erythropoietin is used for treating Chakravarti revolutionn
conditions like anaemia, whereas interferons are
(2) Dr. M. S. (b) White
used to treat viral infections.
Swaminathan and revolution
*(7) : Dwarfness :: Factor VIII :
Dr. Norman Borlaug
Hemophilia
(3) Dr. Verghese Kurien (c) Blue revolution
Ans. Somatostatin - Factor VIII is used for treating
condition like haemophilia, whereas somatostatin (d) Cleaning of oil
is used for treating dwarfism. spillage
*(8) Crop resistant to bollworm :: Crop Ans. (1 - d), (2 - a), (3 - b)
synthesizing large quantities of vitamin A :
*(4) Column ‘A’ Column ‘B’
Golden rice.
Ans. Bt cotton - Golden rice is an improved crop (1) Interferon (a) Diabetes
variety synthesizing large quantities of vitamin A (2) Factor VIII (b) Dwarfness
whereas, Bt cotton is an example of crop resistant
(3) Somatostatin (c) Viral Infection
to boll worm.
(4) Interleukin (d) Cancer
*(9) Osteocytes : Bone cells :: Hepatocytes :
. (e) Hemophilia
Ans. Liver cells - Bone cells are also called as osteocytes, Ans. (1 - c), (2 - e), (3 - b), (4 - d)
while liver cells are also called as hepatocytes.
(5) Column ‘A’ Column ‘B’
*(10) Adhatoda vasica : :: Melia azadiracta
(1) Erythropoietin (a) Viral infection
: Neem
(2) Interferon (b) Dwarfism
Ans. Adulsa - Local name of plant Melia azadiracta is
(3) Insulin (c) Anaemia
neem while local name of plant Adhatoda vasica is
Adulsa. (4) Somatostatin (d) Diabetes
Ans. (1 – c), (2 – a), (3 – d), (4 – b).
Q.1. (A) 4. Match the columns:
Q.1. (A) 5. State whether the statement is true or
(1) Column ‘A’ Column ‘B’
false. Correct the false statement:
(1) National centre for (a) Delhi
(1) Cell Biology includes the study of cell division.
cell science
(2) Stem cells do not play an important role in wound
(2) Instem (b) Pune
healing.
(3) Centre for DNA (c) Bengaluru
(3) Research institutes specially dedicated for
fingerprinting and
research on cells are established at Solapur and
diagnostics.
Nagpur.
(4) Indian Agricultural (d) Hyderabad
(4) Stem cells are present in the umbilical cord by
Research Institute
which the foetus is joined to the uterus of the
Ans. (1 - b), (2 - c), (3 - d), (4 - a) mother.
Cell Biology and Biotechnology 155

(5) 320 different types of cells in human body are (28) Dr. Verghese Kurien has a valuable contribution
formed from single type of cells. in green revolution.
(6) Stem cells are parent cells of all types of human Ans. (1) True (2) False. Stem cells play an important role in
cells. wound healing. (3) False. Research institutes specially
(7) Skin from all parts of the body can be donated. dedicated for research on cells are established at Pune
and Bengaluru. (4) True (5) False. 220 different types
(8) There is considerable progress mainly in the
of cells in human body are formed from single type of
field of agriculture and pharmacy due to
cells. (6) True (7) False. Skin from certain parts of the
biotechnology.
body can be donated. (8) True (9) False. Non genetic
(9) Genetic biotechnology involves use of either cell biotechnology involves use of either cell or tissue.
or tissue. (10) False. Genetically modified Golden Rice variety
(10) Genetically modified Golden Rice variety contains 23 times more amount of Beta Carotene.
contains 50 times more amount of Beta carotene. (11) True (12) True (13) False. Phenylketonuria arises
(11) Vaccines produced with the help of biotechnology due to genetic changes in hepatocytes. (14) False.
There is world - wide opposition to human cloning on
are thermo-stable.
various issues. (15) True (16) True (17) False. 50%
(12) Transgenic E.coli are used for production of to 100% subsidies are offered by Government for
interferon. pisciculture. (18) False. Chemical fertilizers decrease
(13) Phenylketonuria arises due to genetic changes in the fertility of soil. (19) False. Changes in genes of
osteocytes. the cells are brought about in genetic technique. (20)
(14) There is world - wide support to human cloning False. Gene from Bacillus thuringiensis is introduced
on various issues. into cotton and brinjal. (21) False. The bacteria
Deinococcus radiodurans is highly radiation resistant
(15) Grasses like alfalfa, clover, rye are used in
organism. (22) False. Cell differentiation starts from
phytoremediation. 14th day of conception. (23) False. Embryonic cells
(16) DNA sequence of each person is unique as that of before differentiation are called as embryonic stem cells.
the fingerprints. (24) True (25) False. A clone can be produced by fusion
(17) 30% to 60% subsidies are offered by Government of a nucleus of somatic cell with the enucleated ovum.
for pisciculture. (26) True (27) False. Genetically modified variety of
Indian mustard can absorb selenium from the soil.
(18) Chemical fertilizers increase the fertility of soil.
(28) False. Dr. Verghese Kurien has a valuable
*(19) Changes in genes of the cells are brought about in contribtion in white revolution.
non-genetic technique.
Q.1. (A) 6. Name the following:
*(20) Gene from Bacillus thuringiensis is introduced
(1) Special cells present in the body of multicellular
into soyabean.
organisms.
(21) The bacteria Pseudomonas is highly radiation
Ans. Stem cells
resistant organism.
(2) Types of stem cells.
(22) Cell differentiation starts from 5th - 7th day of
Ans. Embryonic stem cells and Adult stem cells.
conception.
(3) Sources of adult stem cells.
(23) Embryonic cells after differentiation are called as
Ans. Red bone marrow, adipose connective tissue and
embryonic stem cells.
blood.
(24) Process of excretion can occur with the help of
(4) Source of stem cell immediately after birth.
single kidney.
Ans. Cord blood
(25) A clone can be produced by fusion of a nucleus of
(5) Organs which can be donated only after death.
ovum with the enucleated somatic cell.
Ans. Liver, heart, eyes.
(26) Genes can also be cloned and millions of copies
(6) Branches of Science included in Biotechnology.
of same gene can be produced.
Ans. Cytology, biochemistry, molecular biology and
(27) Genetically modified variety of cotton can absorb
genetic engineering.
selenium from the soil.
156 Master Key Science and Technology Part-2 (Std. X)

(7) Genetically modified crops. (iii) Indian Institute of Sciences.

Ans. Bt - Cotton, Bt - Brinjal and Golden Rice. (iv) National Pomegranate Research Institute.
(8) Plant used as Biofertilizer. *Q.1. (A) 7. Answer the following in one sentence.
Ans. Azolla (1) What is a cell? (Can you recall; Textbook page no. 88)
(9) Edible vaccines.
Ans. Cell is defined as a basic structural, and functional
Ans. Transgenic potatoes and unit of life.
(10) Protein used in treatment of viral disease. (2) What is a tissue? (Can you recall; Textbook page
Ans. Interferon no. 88)
(11) Genetic disorder in somatic cell Ans. A group of cells having the same origin, same
Ans. Phenylketonuria structure and same function is called as tissue.
(12) New concepts in biotechnology (3) Which technique in relation to tissues have you
Ans. Bio-remediation, biopesticides, biofertilizers, studied in earlier classes? (Can you recall; Textbook
bio-sensors. page no. 88)
(13) Bacteria used as biofertilizer Ans. Tissue culture is the technique studied in earlier
Ans. Rhizobium, Azotobacter, Nostoc, Anabaena. classes.
(4) Just like the grafting in plants, is the organ
(14) Bacterium which is radiation resistant.
transplantation possible in humans? (Use your
Ans. Deinococcus radiodurans
brain; Textbook page no. 89)
(15) Discovery of cleaning of oil-spillage by microbes
Ans. Yes, Human organ transplantation is possible. It
in oceans
is normally the only treatment for end stage of
Ans. Dr. Anand Mohan Chakravarti organ failure such as liver and heart.
(16) Contributors of Green revolution (5) What is biotechnology? (Recall a little; Textbook
Ans. Dr. M. S. Swaminathan, Dr. Norman Borlaug. page no. 91)
(17) Pioneer of White Revolution Ans. The technique of bringing about improvements
Ans. Dr. Verghese Kurien in living organisms by artificial genetic changes
and by hybridization for the welfare of human
(18) Government pisciculture program
beings are together called biotechnology.
Ans. Nil-Kranti Mission - 2016 (NKM - 16).
Q.1. (B) Choose and write the correct option:
(19) Soil less farming.
(1) Stem cell preserved in sterile vials are kept in
Ans. Hydroponics liquid nitrogen at to .
(20) Pesticides (a) –135 °C to –190 °C (b) –125 °C to –150 °C
Ans. DDT, malathion and chloropyriphos. (c) 135 °C to 190 °C (d) 133 °C to 187 °C
(21) Plants used in phyto-remedilation. (2) Indian Agriculture Research institute is at
Ans. Pteris vitata, alfalalfa, clover, rye, sunflower. .

(22) Disease in which cell therapy is used. (a) Solapur (b) Bengalaru (c) Delhi (d) Pune

Ans. Diabetes, myocardial infarction, Alzheimer’s (3) In Nil-Kranti Mission - 2016 program, government
disease, Parkinson’s disease. is offering subsidies of .
(a) 15% - 20% (b) 50% - 100%
(23) Protein used in treatment of viral disease.
(c) 75% - 77% (d) 35% - 50%
Ans. Interferon
(4) Adulsa is taken is cure .
(24) Research institutes in India.
(a) cough (b) fever (c) dysentery (d) vomiting
Ans.
(5) Pesticides are infact a type of  .
(i) Indian Agricultural Research Institute.
(a) fertilizer (b) poison
(ii) National Citrus Research Institute.
(c) manner (d) organic product
Cell Biology and Biotechnology 157

(6) In soil-less farming i.e. hydroponics (4) Genetically Modified crops

chemical fertilizer are used. Ans. Crops developed with desired characters by
(a) solid (b) liquid (c) gaseous (d) plasma integrating foreign gene with their genome are
(7) National pomegranate Research Institute is called as genetically modified crops.
located at .
(5) Vaccine
(a) Solapur (b) Pune
Ans. Vaccine is the antigen containing material
(c) Nagpur (d) New Delhi
given to acquire either permanent or temporary
(8) DNA fingerprinting is mainly useful in
immunity against a specific pathogen or disease.
science.
(a) formal science (b) natural science (6) Cloning.
(c) social science (d) forensic science Ans. Production of replica of any cell or organ or entire
(9) Interferon is a group of small sized protein organism is called cloning.
molecule used in treatment of (7) Bio-remediation
disease. Ans. Absorption or destruction of toxic chemicals and
(a) cancer (b) diabetes (c) anemia (d) viral harmful pollutants with the help of plants and
(10) Cattle feeding on transgenic does micro-organisms is called as bio-remediation.
not contract a viral disease-rinderpest.
(8) Blue revolution
(a) potato (b) onion (c) tobacco (d) tomato
Ans. Production of various useful acquatic organisms
(11) Human Insulin gene now is been inserted into
with the help of water is called as blue revolution.
the genome of .
(9) Cell therapy
(a) horse (b) cat (c) bacteria (d) virus
(12) Stem cells are present in . Ans. The use of stem cells to replace the dead cells in
conditions like diabetes, myocardial infarction,
(a) umbilical cord (b) bone marrow
Alzheimer’s disease, etc. is called cell therapy.
(c) adipose connective tissue
(10) Biotechnology
(d) All of the above
(13) A clone is produced by fusion of nucleus of Ans. Biotechnology is bringing about artificial genetic
somatic cell with an enucleated. changes and hybridization in organisms for
(a) sperm (b) ovum (c) stem cell (d) hepatocyte human welfare.
Ans. ( 1) (a) –135°C to –190°C, (2) (c) Delhi (3) (b) 50% - Q.2.2. Write short notes:
100% (4) (a) cough (5) (b) poison (6) (b) liquid (1) Stem Cells.
(7) (a) Solapur (8) (d) forensic science (9) (d) viral
(10) (d) tomato (11) (c) bacteria (12) (d) All of the Ans.
above (13) (b) ovum. (i) Stem cells are special types of cells present in the
Q.2.1. Define the following: body of multicellular organisms.
(1) Cytology / Cell Biology (ii) These cells give rise to all other types of cells.
Ans. The study of cell division, structure, types and (iii) These cells play an important role in wound
organelles of the cell is called as Cytology/Cell healing. All the stem cells are almost alike when
Biology. they are in the form of a mass of cells during
(2) Stem cells earliest stage of development.
Ans. Special type of cells present in the body of (iv) During further development, stem cells undergo
multicellular organisms, which give rise to all
cell differentiation.
other types of cells present in the body are called
as stem cells. (v) Stem cells are present in umbilical cord,
(3) Pleuripotency blastocyst stage of embryonic development, red
bone marrow, adipose connective tissue.
Ans. Stem cells are primary type of undifferentiated
cells with self multiplying ability and they are (vi) It has become possible to produce different types
parent cells of all types of human cells. This of tissues and the degenerated part of any organ
property of stem cells is called as Pleuripotency. with the help of these stem cells.
158 Master Key Science and Technology Part-2 (Std. X)

(vii) Stem cells are of two types - Embryonic stem cells (ii) Use of productivity of cells eg. Production
and Adult stem cells. of antibiotics and vaccines with the help of
(2) Organ transplantation. specific cells.
Ans. (iii) Use of bio-molecules like DNA and proteins in
(i) Various organs in the human body become human welfare.
less efficient or completely functionless due to (iv) Development of plants, animals and products
various reasons like ageing, accidents, infections, of desired quality by gene manipulation. eg.
disorders, etc. Production of growth hormone with the help of
(ii) Life of such person becomes difficult or fatality genetically modified bacteria.
may occur and life can be saved when the person (v) Use of genetic and non-genetic technique.
gets the necessary organ.
Non-genetic biotechnology involves use of either
(iii) Availability of donor is an important requirement
cell or tissue. eg. tissue culture, production of
in organ transplantation.
hybrid seeds.
(iv) As the process of excretion can occur with the
(5) Benefits of Biotechnology.
help of single kidney, person can donate the other
one. Similarly, skin from certain parts of the body Ans.
can be donated. (i) It has become possible to increase the per
(v) Various factors like blood group, diseases, hectre yield irrespective of the limitations of
disorders, age, etc. of the donor and recipient crop-land area.
need to be paid attention during transplantation. (ii) Expenses on disease control have minimized
(vi) Organs like liver, heart and eyes can be donated since development of resistant varieties.
after death only, i.e. posthumous donation of (iii) Due to development of fast fruit setting varieties
body and organs.
yield per annum has been increased.
(3) Organ and body donation.
(iv) Development of stress resistant varieties which
Ans. can withstand variable temperature, water-stress,
(i) Many organs remain functional for certain period changing fertility of soil, etc. has become possible.
even after death occurs under specific conditions.
(6) Genetically modified crops.
(ii) Organs or body donation can save life of other
Ans.
needful persons.
(i) Crops developed with desired characters by
(iii) A miserable life can be made comfortable after
integrating foreign gene with their genome are
death. Body can be made available for research in
medical studies. called as genetically modified crops.

(iv) Awareness about these concepts is increasing in (ii) High yielding varieties with resistance to disease,
our country and people are voluntarily donating alkalinity, weeds other stresses like extreme cold
their bodies. and drought are produced.
(v) Life of many people can be saved by organ and (iii) A gene had been isolated from the bacterium
body donation. Bacillus thuringiensis and integrated with the gene
(vi) Blinds can regain the vision. of cotton and brinjal.
(vii) Life of many people can be rendered comfortable (iv) This improved variety - Bt cotton, Bt Brinjal kills
by donation of organs like liver, kidneys, heart, the pests and yield is maintained.
heart-valves, skin, etc. (iv) A gene synthesizing the Vitamin A (Beta carotene)
(viii) Many government and social organisations are has been introduced in the variety of rice. This
working towards increasing awareness about variety contains 23 times more amount of beta
body donation. carotene than the original variety.
*(4) Biotechnology : Professional uses. (v) Herbicide tolerant plant varieties are being
(i) Use of various abilities of microbes like yoghurt developed. Due to this, it has become possible to
production from milk and alcohol from molasses. selectively destroy the weeds.
Cell Biology and Biotechnology 159

(7) Biofertilizers. (iii) He put forward the co-operative dairy movement

Ans. of Anand, Gujarat at all time high status.
(i) Due to use of biofertilizers instead of chemical (iv) While achieving self-sufficiency in dairy business
fertilizers, nitrogen fixation and phosphate various experiments were performed for
solubilization abilities of the plants are improved. quality control, newer dairy products and their
(ii) Mainly the bacteria like Rhizobiun, Azotobacter, preservation.
Nostoc, Anabaena and plants like Azolla are used (11) Blue revolution.
as biofertilizers. Ans.
(8) Edible vaccines. (i) Production of various useful aquatic organisms
Ans. Edible vaccines are given as food by incorporating with the help of water is called as blue revolution.
them in food stuff.
(ii) Farm ponds and fishes are very common in East
(i) Work on production of edible vaccines is in Asian countries.
progress and presently, potatoes are being
(iii) Along with aquatic plants and animals, fishes
produced with the help of biotechnology.
and shrimps are also cultivated.
(ii) These potatoes are called as transgenic potatoes.
(iv) Government of India has vowed to increase
(iii) These potatoes will act against bacteria like Vibrio
the production by encouraging the people for
cholerae, Escherichia coli.
pisciculture by launching Nil-Kranti Mission -
(iv) Consumption of these raw potatoes generates 2016 (NKM - 16) program. 50%-100% subsidies
immunity against cholera and the diseases due to
are offered in this case.
E-coli.
(v) Marine and fresh water fishery is possible on
(9) Green Revolution.
large scale.
Ans.
(vi) Fresh water fishes like rohu, catla and other
(i) Various methods applied for harvesting
fishery products like shrimp and lobsters are
maximum yield from minimum land are
being cultured on large scale.
collectively called as green revolution.
(12) Organic farming.
(ii) At the beginning of the 20th century all the
underdeveloped and developing countries had Ans.
been badly affected by the effects of poor quality (i) Organic farming relies on fertilizers of organic
and quantity of food. It was one of the problem of origin such as compost manure, green manure
population explosion. and places emphasis on biological pest control.
(iii) Improvised dwarf varieties of wheat and rice, (ii) It includes complete ban on chemical fertilizers
proper use of fertilizers, pesticides and water and pesticides and use of local, sturdy varieties
management has led to the increased production and thereby maintaining natural balance.
of food grains and thereby large population had
(iii) Poisonous chemicals from pesticides, chemical
been saved from hunger.
fertilizers have reached the human body through
(iv) Dr. Norman Borlaug (USA) and Dr. M. S.
food and water.
Swaminathan (India) have made valuable
contribution in green revolution. (iv) Their effects on environment like reducing soil
fertility, pest infestation and harmful effects on
(10) White revolution.
human body are apparent.
Ans.
(v) Hence, organic farming is a welcome decision.
(i) Various parts of India were rich in milk and milk
products. However, these products were not *(13) Importance of medicinal plants.
sufficient to meet the needs of far-flung regions. Ans.
(ii) Dr. Verghese Kurien proved through the co- (i) India has been gifted with a great biodiversity.
operative movement and use of biotechnology Indian citizens have a strong and humble relation
that Dairy cannot be allied but a mainstream with nature.
business.
160 Master Key Science and Technology Part-2 (Std. X)

(ii) We have a great tradition of ayurveda that cures Plants like lemon, turmeric, Aloe-Vera, Adulsa,
the diseases with the help of natural sources. Basil, Neem, Garlic, Ashwagandha, etc. are used
(iii) Medicinal plants find applications in food to cure many ailments.
industry, pharmaceuticals, agriculture and (v) Many of these remedies are present in the house
cosmetics. itself.
(iv) There are infinite medicinal plants which come (vi) Many plants have various parts that are used like
together and form a branch of medical science
roots, bark stem, leaves, fruits, etc.
called ayurveda.
Q.2.3. Distinguish between:
(1) Stem cells and cells
Ans. Stem Cells Cells
(i) Stem cells are formed during the blastocyst (i) Cells are formed from stem cell by the process of
stage of embryonic development. cell differentiation.

(ii) Present at selective places in the body like (ii) Present everywhere in the body.
cord blood, connective adipose tissue,
bone marrow, etc.

Q.2.4. Answer the following: (iv) It has become possible to treat PKT with gene
(1) State the uses of stem cells. therapy.
Ans. (4) What is DNA finger printing?
(i) Regenerative Therapy: Ans.
(a) Cell Therapy : Stem cells are used to replace the (i) DNA sequence of each person is unique as that of
dead cells in case of conditions like diabetes, the fingerprints.
myocardial infarction, Alzheimer’s disease, (ii) Due to this, identity of any person can be
Parkinson’s disease, etc. established with the help of its available DNA.
(b) To produce blood cells required in conditions like This is called as DNA fingerprinting.
anaemia, thalassaemia, leukemia, etc. (iii) It is mainly useful in forensic sciences.
(ii) Organ Transplantation : In case of failure (iv) Identity of the criminal can be established with
of organs like kidney and liver, those can the help of any part of its body found at the site
be produced with the help of stem cells and of crime.
transplanted. (v) Similarly, identity of father of any child can be
*(2) In which various fields the biotechnology has established.
been useful? (Recall a little; Textbook page no. 91) (vi) This research is performed in Center for DNA
Ans. It is useful in production of cash crops, fingerprinting and Diagnostics, Hyderabad.
improvement in varieties of cash crops, increase (5) How are stem cells preserved?
in abilities of plants to withstand environmental Ans.
stresses, vaccine production, early diagnosis of
(i) For preservation, stem cell samples are carefully
congenital diseases, organ transplant, cancer
collected from sources like cord blood, red bone
research, production of artificial skin, cartilage,
marrow or embryo (blastocyst) and are kept in
etc. in laboratories.
small, sterile vials.
(3) What is Gene therapy? o
(ii) Those vials are kept in liquid nitrogen at –135 C
Ans. o
to –190 C.
(i) Gene therapy to treat genetic disorders in somatic *(6) What are the functions of tissue? (Can you recall;
cells has become possible due to biotechnology. Textbook page no. 88)
(ii) All the cells except sperms and ova in the body Ans. Functions of tissues are also based on its types.
are called as somatic cells. Connective tissue : Function is to give shape to
(iii) E.g. Phenylketonuria (PKT) arises due to genetic organs and hold them in place.
changes in hepatocytes (liver cells). Muscular tissues : cause movement.
Cell Biology and Biotechnology 161

Epithelial tissues : Protection of external / (iii) So herbicide tolerant plant varieties of crops are
internal organs, absorption of water / nutrients being developed.
and elimination of waste. (iv) Due to this, it has become possible to selectively
Secretion of enzymes and hormones. destroy the weeds.
Nervous tissue : Enables us to respond to stimuli (2) DNA fingerprinting is useful in forensic
like touch, sound, odour, colour etc. sciences and paternity testing.
*(7) Which are the various processes in tissue Ans.
culture? (Can you recall; Textbook page no. 88)
(i) DNA sample helps to establish identity of each
Ans. The various processes used in tissue culture are individual.
as follows:
(ii) Each individual has a unique DNA sequence
(i) Selection of source plant. pattern and so it is called as DNA fingerprint of
(ii) Removal of Bulb corm of source plant. each individual.
(iii) Primary treatment of the part. (iii) Identity of a criminal can be found easily from
(iv) Reproduction and Multiplication. various sources of DNA (blood, semen, etc.) on a
(v) Shooting and Rooting crime scene.
(vi) Primary hardening. (iv) DNA fingerprinting is also done for paternity
(vii) Secondary hardening. testing.

*(8) Which new species of the rice have been Q.3.1. Answer the following:
developed in India? (Collect information; Textbook *(1) Why some of the organs in human body are
page no. 97) most valuable?
Ans. Ans. 
Various organs in human body become less
(i) BPT 2270 (Bhavapuri Sannalu) efficient or completely functionless, due to various
(ii) BPT 2231 (Akshaya) reasons like ageing, accidents, infections etc.
(iii) Pusa 1460 (ii) Life of such persons become difficult, miserable,
(iv) RPB10226 uncomfortable. Sometimes fatality may also
*(9) Which products produced through biotech- occur.
nology do you use in your daily life? (iii) Many organs in human body remain functional
Ans. for certain period even after death occurs under
specific conditions.
(i) Biodiesel
(iv) These organs can be transplanted on donation.
(ii) Household products : Washing detergents.
(iii) Bioplastic Hence, certain organs like heart, kidneys, eyes,
liver, heart valves, skin, etc. are more valuable.
(iv) Fabric
*(2) Explain the importance of fruit processing in
(v) Personal care products : Shampoos, skin care, etc.
human life.
(vi) Food and drink : Flavours, fragrances, Sweetners
Ans.
yoghurt, cheese, juicy and pulpy fruits, Golden
rice, GM crops, bread, vinegar, wine, beer, etc. (i) Fruits are perishable agro - produce.
(vii) Healthcare - Vaccines, antibiotics, etc. (ii) Fruits contain vitamins, proteins, minerals and
dietary fibres.
Q.2.5. Give Scientific reasons:
(iii) There is a need to process fruits in order to
(1) Herbicides tolerant plant varieties of crops are
increase their storage or shelf - life significantly.
being developed.
(iv) Various products are prepared from fruits like
Ans.
chocolates, jams, juices and jellies and are used
(i) Weeds always affect the growth of main crop.
daily.
(ii) If herbicides are used to destroy the weeds, it
(v) Fruit processing is done in such a way that it can
affects the main crop too.
be used throughout the year.
162 Master Key Science and Technology Part-2 (Std. X)

(vi) Fruit processing include various methods (iv) Due to development of fast fruit setting varieties,
ranging from cold storage to drying, salting, air yield per annum has been increased.
tight packing, pickling, evaporating, etc. (v) Development of stress resistant varieties which
*(3) Explain the meaning of Vaccination. can withstand variable temperature, water-
Ans. stress, changing fertility of soil, etc. has become
possible.
(i) Vaccine is the antigen containing material
given to acquire either permanent or temporary (vi) Biofertilizers, bioinsecticides have been
immunity against a specific pathogen or disease. developed with the help of biotechnology which
prevent the soil from being polluted and increase
(ii) Traditionally, vaccines were prepared with the
the yield.
help of pathogens which may be completely or
(vii) With the help of biotechnology, plants and
partially killed.
microorganisms are used for absorption or
(iii) However due to this, there were chances of destruction of toxic chemicals and harmful
contracting the disease in certain persons. pollutants. This is called bioremediation.
(iv) Hence, as an alternative, scientists have given (5) Why are artificial bee boxes used for Apiculture?
artificially produced vaccines with the help of
Ans.
biotechnology.
(i) Worst method of harvesting / collecting the
(v) A safer vaccine was produced with the help of
honey from bee hives is driving away the bees
gene isolated from the pathogen and an antigen
by smoking the hive with burning torch and then
produced from it.
cutting the hive into pieces.
(vi) Now, proteins which act as antigens are injected
(ii) This causes destruction of hive and large scale
in pure form instead of injecting the killed or
death of bees.
semikilled pathogens.
(iii) Hence with artificial bee box it is easy to collect
(vii) These proteins keep the persons away from the
the honey without destroying the hive and bees.
disease by keeping the immune system active.
(6) Explain the extraction of Insulin.
(viii) Vaccines produced with the help of biotechnology
are more thermostable and remain active for Ans.
longer duration. E.g. vaccines of polio, hepatitis (i) Earlier, insulin was being collected from the
etc. pancreas of horses.
(ix) Edible vaccines are produced in combination (ii) Nowadays, due to biotechnology, insulin is
with transgenic potatoes. These potatoes will act prepared with the help of bacteria.
against bacteria like Vibri o cholerae and Escherichia (iii) For this purpose, human insulin gene has been
coli and consumption of such raw potatoes will inserted into the genome of bacteria.
generate immunity against cholera and various *(7) Give 5 examples of each of the fruiting and
other disease caused by E. coli. flowering plants developed through tissue
*(4) What is the impact of biotechnology on culture and mention their benefits. (Make a list
agriculture and other related fields? (Recall a and discuss; Textbook page no. 93)
little; Textbook page no. 91) Ans. Fruits and flowers developed through tissue
Ans. culture are :
(i) Genetically modified crops are being produced Fruits : Pineapple, Banana, Pomegranate, Papaya
by introducing changes in DNA of natural crops. Apple, etc.
(ii) It has become possible to increase the per hectare Flowers : Marigold, Rose, Shevanti, Lily, Gerbera
yield irrespective of the limitations of crop-land daisy, etc.
area. Benefits of tissue cultured fruits and flowers:
(iii) Expenses on disease control have minimized (i) These are almost pest and disease resistant.
since development of resistant varieties.
(ii) Mature plant is obtained in less time.
Cell Biology and Biotechnology 163

(iii) More plants with desired characteristics like body donation is that after death. Our body
bigger size, colourful fruits and disease resistance, should be useful to other needful persons so that
etc. are obtained. their miserable life would be comfortable.
(iv) Planting is possible all through the year. (3) Amol has renal failure. His Nephrologist has
(v) Rare and endangered varieties also can be grown advised him renal transplant.
by tissue culture. (i) Can his mother donate him one kidney?
*(8) Which fruit processing industries you observe Ans. 
Amol’s mother can donate him one kidney as the
in your surrounding? What is their effect? (Make process of excretion can occur with the help of
a list and discuss; Textbook page no. 99) single kidney.
Ans. (ii) What factors should be checked before
(i) Fruit processing industries like Jam making, transplant by the doctor for Amol’s mother and
Jelly-making industries are observed in the Amol.
surrounding. Ans. 
Doctor will cross check factors like blood group,
(ii) Fruit processing industries directly have a disease disorder, age, etc. of the donar - Amol’s
positive impact on higher productivity, improved mother and Amol i.e. recipient.
quality and safety (in the farming sector). Q.3.3.Label the diagram and answer the questions
(iii) It benefits the local farmers. below:
(1)
(iv) These industries power the wastage and increase
the shelf life of fruits by involving scientific Can replicate
methods. Stem cells themselves

(v) These industries create employment in rural and

semi urban regions and boost rural economy.

Q.3.2. Answer the following questions:

*(1) Mohan is suffering from Cirrhosis of Liver. His
chances of survival is only 20%. Doctors are
Can be transformed into
advising transplant of the Liver. other types of cells
(i) What are the 2 possibilities of saving Mohan’s Fig. 8.1. Stem cell therapy
life.
(a) Label the diagram and give a heading.
Ans. 
Steam cell transplant and organ transplant are the
Ans. Stem cell therapy.
two possibilities of saving Mohan’s life.
(b) Which type of cells are shown in the diagram?
(ii) What factor should be considered before
Ans. Stem cells are shown in the diagram.
transplant of the liver by Mohan and the donar.
(c) Define the type of cells.
Ans. 
Factors like blood group, disease, disorder, age,
etc. of the donar and the recipient - Mohan should Ans. (i) Stem cells are special cells present in the
be checked. body of multicellular organisms, formed at the
blastocyst stage of embryonic development. (ii)
(2) 2.5 years old yagnesh has met with an accident.
These cells give rise to all other types of cells.
He has lost his life. His parents want to donate
(d) Which cells can be formed due to the cell
his organs?
mentioned in the diagram?
(i) Which organs can be donated after death.
Ans. Stem cell gives rise to neurons, hepatocytes, (liver
Ans. 
Yagnesh parents can donate his heart, pancrease, cells), Osteocytes (bone cells).
kidneys, skin, bone, liver, lungs and eyes.
(e) State any one use of these cells with respect to
(ii) Which concept has convinced Yagnesh parents the diseases cured by it.
for donating his organs?
Ans. Diseases like diabetes, myocardial infarction, etc.
Ans. 
A liberal view behind the concept of organ and can be cured by stem cells.
164 Master Key Science and Technology Part-2 (Std. X)

*(2) Eyes
Heart
Bulb corm of
source plant

Source plant
Lungs
Pancreas
(iv) (i) (ii)
Kidney
Liver

Bone (iii)
Skin

Reproduction /
Multiplication
Fig. 8.3 Tissue Culture

Fig. 8.2. Organs that can be donated Ans. (A) Various processes in tissue culture
(B) Primary treatment (C) Shooting and rooting
(a) Label the organs in the diagram and name the
(D) Primary hardening
diagram / caption.
(i) The diagram represents the various processes in
Ans. Organs that can be donated.
tissue culture staring with source plant.
(b) List the organs that can be donated.
(ii) Primary treatment : It is the initiation phase. Plant
Ans. Organs that can be donated - eyes, lungs, liver, tissue is sterilized In vitro and initiated into culture.
bones, heart, pancreas, kidney, skin
(iii) Shooting and rooting : It is the phase of root
(c) What is posthumous donation? formation. Hormones are introduced to induce
Ans. Posthumous donation is donation of body and rooting and also for the formation of a complete
organs, after death. plantlet.
*(3) Assign names in the figure given below. Explain (iv) Primary hardening: Hardening is gradually
the various stages those are kept blank. (Observe; exposing the plants to adjust to the environment
Textbook page no. 88) conditions.

(4) Based on the Genetically modified crops fill in the blanks and answer the questions based on it.

Bt Cotton Bacterium
Bacillus
thuringiensis
Genetically
Bt Brinjal Bacterium
Modified crops

Golden Rice

(a) What is produced in the leaves of cotton plant?

Ans. Toxin.
(b) How does the bollworm die?
Ans. If the worm feeds on leaves, the toxin destroys its alimentary canal and the worm dies.
(c) Which type of gene is introduced in Golden Rice?
Ans. A gene synthesizing the Vitamin A (Beta Carotene) has been introduced is this variety of rice.
Cell Biology and Biotechnology 165

Q.3.4. Complete the following chart:

Cleaning hydrocarbons
(1) and oil pollutants

Pseudomonas

Absorbs Deinococcus Absorbs uranium

Bioremediation Sunflower
radiation radiodurans and arsenic

Pteris vitata

Absorbs arsenic
from the soil

*(2) *(3) Write the correct answer in blank circles.

Organ
Regenerative
Transplantation
Increase per Development Therapy Uses of stem
hectare yield of resistant cells
varieties minimise
Human expenses on
Health Organ and Body
disease control
Donation

(4) Complete the following chart.

Cloning Vaccines
Merits of Development
Genetically Human Health
Biotechnology of fast fruit
modified crops Management
setting varieties
increases in yield Gene
Interferon Treatment
Therapy

(6) Complete the following chart.

Hybrid Stem cells
seeds Development of
Animal stress resistant
Husbandary varieties Neuron Osteocytes Hepatocytes Cardiac Columnar
cells epithelium

Brain Bone Liver Heart Intestine

Q.4.1. Explain the formation of transgenic potatoes with the help of a diagram.
Ans.


Isolation of Transgenic Virus infects Entire plant is developed Consumption of raw

desired gene plant virus. the pieces of from the leaf pieces potatoes helps to develop
from human potato leaves. containing genes of immunity
pathogen human pathogen. against that pathogen
Fig. 8.4 Transgenic Potatoes
166 Master Key Science and Technology Part-2 (Std. X)

Q.4.2. Read the given paragraph and answer the (d) Where is DNA fingerprinting research
questions: performed?
(1) Ans. DNA fingerprinting research is performed at the
‘Centre for DNA fingerprinting and Diagnostics’,
Work on production of edible vaccines is in
Hyderabad.
progress and presently, potatoes are being
produced with the help of biotechnology. These (3)
potatoes are called as transgenic potatoes. A sheep ‘Dolly’ was born in Scotland by cloning
These potatoes will act against bacteria like technique on 5th July 1996. Nucleus from the
Vibrio cholerae, Escherichia coli. Consumption udder cell of sheep of ‘Finn Dorset’ variety
of these raw potatoes generates the immunity had been introduced into enucleated ovum of
Scottish sheep. Then, the ovum was allowed
against cholera and the disease caused due to
to develop in the uterus of Scottish sheep and
E. coli.
thereby ‘Dolly’ had been born. It was showing
(a) Edible Vaccines are taken in which form of the characters as per the chromosomes in
nucleus and any character of Scottish sheep
food?
was not visible.
Ans. Potatoes.
(a) In which year was the first cloning technique
(b) What is the other name of this food?
done?
Ans. Transgenic potatoes.
Ans. The first cloning technique was done on 5th July
(c) List the bacteria against which these food will 1996.
act.
(b) Name the varieties of sheep breed used to form
Ans. Vibrio cholerae, Escherichia coli. the clone.
(d) Against which disease immunity is generated?
Ans. Finn Dorset and Scottish sheep were breed used
Ans. Immunity is generated against cholera and to form the clone.
disease caused due to E. coli.
(c) Explain the meaning of the word enucleated
(2) ovum.
DNA sequence of each person is unique as Ans. Enucleated ovum means to remove nucleus of
that of the fingerprints. Due to this, identity cell, and the cell loses all its genetic information.
of any person can be established with the help (d) Whose character Dolly was showing and why?
of its available DNA. This is called as DNA
Ans. Sheep Dolly was showing characters of Finn
fingerprinting. It is mainly useful in forensic Dorset as nucleus which contains genetic material
sciences. Identity of the criminal can be (DNA) from the udder cell of sheep Finn Dorset
established with the help of any part of its body was taken and enucleated ovum of Scottish sheep
found at the site of crime. Similarly, identity was taken.
of father of any child can be established. This
Q.4.3. Answer the following in detail:
research is performed in Centre for DNA
*(1) Which precautions you will take during
fingerprinting and Diagnostics, Hyderabad.
spraying of pesticide?
(a) What is DNA fingerprinting? Ans. 
Ans. Establishing identity of a person with the help of (i) Pesticides are in fact a type of poison. This poison
its available DNA is called as DNA fingerprinting. enters the food web through water, food and its
bio-magnification occurs.
(b) DNA fingerprinting is mainly used in which
stream of science? (ii) Various pesticides like DDT, malathion,
chloropyriphos, etc. are dangerous.
Ans. DNA fingerprinting is mainly used in forensic
(iii) Precautions to be taken are as follows:
science.
(a) Apply only recommended dose.
(c) What is the use of DNA fingerprinting?
(b) Cover nose with cloth before spraying or
Ans. It is used to identify criminals. It is also used in
even filling up the pump can of pesticide.
parternal or maternal identification.
Cell Biology and Biotechnology 167

(c) Always wear gloves while handling the (iv) Thus, biotechnology should be balanced.
apparatus. (3) What is Biotechnology? What are its commercial
(d) Avoid spillage of pesticide. applications?
(e) Do not smell the pesticide. Ans.
(f) Read the instructions carefully. (i) Biotechnology is bringing about artificial genetic
(g) Do not apply against the wind direction, changes and hybridization in organisms for
rains, sunny day. human welfare.

(h) Containers, buckets used for spraying should (ii) Various branches of science like cytology,
not be used for domestic purposes. biochemistry, molecular biology and genetic
engineering are included in biotechnology.
(i) Avoid entry of animals and workers in the
(iii) Commercial applications of biotechnology are as
field during spraying.
follows:
*(2) Write a comparative note on usefulness and
(a) Crop Biotechnology: Biotechnology is used in
harmfulness of biotechnology.
agricultural field to improve yield and variety,
Ans. Usefulness of biotechnology: i.e. hybrid seeds, genetically modified crops,
(i) Biotechnology has worked for human welfare. herbicide tolerant plants and biofertilizers.
(ii) There is considerable progress in the field of (b) Animal Husbandry: Artificial insemination
agriculture, pharmacy, plant as well as animal and embryo transfer are used to improve
life. quality and quantity of animal products.
(iii) Scientist have modified plants, animals, human (c) Human Health: Diagnosis and treatment of
beings using various techniques of biotechnology. the disease are two aspects of human health
(iv) Biotechnology has modified shape, size, taste, management.
seed/seedless fruits and vegetables. (d) With the help of biotechnology, disease can
(v) Reliable, rapid and consistent enzymes have be diagnosed before the onset of symptoms.
been created which play a mojor role in food (e) Vaccines and vaccination, treatment,
processing. interferon, gene therapy, cloning, i.e.
(vi) A number of dairy products are made available reproductive and therapeutic cloning are
to us. also some important developments of
biotechnology.
(vii) A number of human and animal diseases have
(f) Industrial Products: Various industrial
found cure and prevention.
chemicals can be produced through less
(viii) Biotechnology has modified plants to have their
expensive processes.
own pest resistant traits.
(g) Environment - Biotechnology helps in solving
(ix) Diagnostic kits are available for various diseases. various environmental problems.
Harmful effects of Biotechnology are as follows. (h) Food Biotechnology: Improved quality of
(i) High cost of genetic engineering apparatus. food is produced with the help of micro
(ii) Crosses between different species gives rise to organisms.
hazardous organisms. (i) DNA fingerprinting: Identity of any person
(iii) During experimentation when more Transgenic can be established with the help of its
potatoes are grown, it can be life threatening available DNA.

vvv
168 Master Key Science and Technology Part-2 (Std. X)

ASSIGNMENT - 8
Time : 1 hr. Marks : 20

Q.1. (A) Answer the following questions: (3)

(1) Fill in the blanks:
The disease related with synthesis of insulin is .................. .
(2) Find the odd one out:
Red bone marrow, adipose connective tissue, blood, neurons.
(3) Complete the analogy:
Interferon : .................. : : Erythropoietin : Anemia.
Q.1. (B) Choose and write the correct option: (2)
(1) From the following processes find the odd-one out .................. .
(a) Biopesticide (b) Biotertilizers (c) Biosensors (d) Biology.
(2) Phenylketonuria arises due to genetic changes in .................. .
(a) neurons (b) hepatocytes (c) osteocytes (d) blood corpuscles.

Q.2. Answer the following questions: (Any 2) (4)

(1) Write short note on : Biofertilizers
(2) Give Scientific reason:
Sewage should be released into rivers only after oxidation.
(3) 19 year old Trisha has died after meeting with an accident. Parents are in deep grief and
have decided to opt for organ and body donation. What is basic thought process behind the
parents action?

Q.3. Answer the following questions: (Any 2) (6)

(1) Explain the concept of Genetically Modified Crops.
(2) Explain DNA fingerprinting.
(3) Complete the following tree diagram based on main areas of biotechnology.

Productivity Gene
Areas
of cells manipulation
(A) (B) (C) (D) (E)

Examples Yogurt DNA Tissue culture

Q.4. Solve the following subquestions: (Any 1) (5)

(1) Draw a well labelled diagram of Transgenic potatoes and explain it.
(2) Write a comparative note on usefulness and harmfulness of Biotechnology.

vvv
 9 Social Health
CONCEPT MAP
(1)

Factors disturbing the social health

Mental stress Addiction Incurable diseases Excessive use

of modern
technology

Effect on Cyber
health crimes

(2)

Satisfying basic needs of Education Financial Status Gardens Social and physical
persons - Food, clothing, conditions of the
shelter, medicines etc. surrounding.

Education and Job Social environment

Opportunities of the surrounding.
Factors
Transport
affecting social Residential area
Facilities
health

Water
Social safety

Toilets
Social treatment Playgrounds Political conditions (views)

(3) Spending time with Exercise,

your pet
walking, jogging Reducing caffeine intake
Listen to soothing
music
Focussing your
Take a Yoga class, deep breathing Human Being
thoughts on positivity
Avoid
pro crastination Being with nature
Learn to
Laughing Spending time with
say ‘no’
out loud friends and family

(169)
170 Master Key Science and Technology Part-2 (Std. X)

Points to Remember:
zz Social health is the ability of a person to establish relationship with other persons.
zz Factors disturbing the social health
zz Mental stress
- Competition has increased in opportunities for education, employment and business due to increase in
population.
- There are many bindings on girls and excessive freedom for boys in some families.
- In our society, adolescent girls have to unnecessarily face the problems like teasing and molestation.
- Everyone has to face the stress due to ever increasing disorder, crime and violence.
zz Addiction
- Children in early age try upon tobacco, cigarette, gutka, alcoholic drinks, drugs, etc. due to either peer
group pressure or symbol of high standard of living or as an imitation of elders.
- It may lead to addiction to such deadly substances
zz Incurable disease - Factors like ignorance towards the people with incurable diseases like AIDS, T.B., leprosy
and mental disorders as well as old people lead to increase in old age homes.
zz Communication media and excessive use of modern technology
- People spend time with cell phones for several hours are usually unaware of their surroundings. This is
also a sort of addiction and leads to endangering of social health.
- Various physical problems like tiredness, headache, insomnia, forgetfulness, tinnitus, joint pains and
problems in vision may arise due to radiation of cell phones.
- Children who watch cartoon films may imitate characters of those films.
- Huge information available on internet is used for viewing some inappropriate videos too.
- Person indulging in selfie is not aware about the world around and the risks. This is called as selfiecide.
zz Cyber Crimes
- Banking transaction are done using PIN without the knowledge of consumers.
- Hacking information of the customers, government institutes, companies and misusing them.
- Crimes like opening a fake account on facebook and displaying false information and thereby, harassing
girls also take place.
zz Stress Management
- Various ways of expression like establishing communication with friends, peers, cousins, teachers and
more importantly parents, noting down our feelings, expressing our feelings with near and dear ones
help us to relieve stress.
- Name of newly popularized concept is laughter club. These people relieve their mental stress by laughing
loudly.
- Fostering the hobbies help us to properly utilize free hours.
- By diverting energy and mind towards positive thinking, negative thoughts are automatically neutralised.
- Learning and listening to the music, singing keeps us happy and drives away stress.
- Regular exercising, massaging, visiting the spa too helps to relieve stress.
- Medical advice, counselling and psychotherapy are available for persons with serious problems like
depression and frustration.
- Unified movement against Tobacco has been started by various organizations.
- This movement is active for controlling the tobacco consumption and providing guidance to activists against tobacco.
zz Salaam Mumbai Foundation
- This organisation runs programs in various schools in Mumbai to empower the children living in slum
area in the field of education, sport, arts and business.
- Phone number / helpline numbers are published in newspapers to help the children in distress or facing
any type of problems. Proper help and guidelines are offered to children.
Social Health 171

(3) Website, movies and cartoon films inappropriate

MASTER KEY QUESTION SET - 9 for children, are banned by the government.
Q.1. (A) 1. Fill in the blanks and rewrite the statement: (4) Children are facing problems of loneliness and
*(1) Laughter club is a remedy to drive away mental stress due to nuclear family and parents
. staying outdoors for job.

*(2) Alcohol consumption mainly affects (5) Brain development in adolescents is hindered
due to alcoholism.
system.
(6) Spending time with cell phones for several hours
*(3) The act is to curb the cyber crimes.
is a sort of addiction.
(4) Ability to change one’s own behaviour according
(7) Radiations of cell phones penetrate the bones of
to changing social conditions is an important
adults more effectively than the bones of children.
characteristic of .
(8) Parents threatening or hitting the children is a
(5) girls have to unnecessarily face the
type of mental illness.
problems like teasing and molestation.
(9) Person indulging in selfie is aware about the
(6) has the power of changing the world around and the risks.
mindset.
(10) Banks ask our PAN/Credit card/ debit card
(7) is active for controlling the tobacco number on mobile phones.
consumption.
(11) Committing cyber crimes is a mental illness.
(8) is the ability of a person to establish
(12) Yoga is limited to asanas and pranayam.
relationship with other persons.
Ans. (1) True (2) False : Addictive person cannot think
(9) is produced from alcohol obtained rationally (3) True (4) True (5) True (6) True
through fermentation of substances. (7) False : Radiations of cell phones penetrate the
(10) Persons continuously using the computers and bones of children more effectively than the bones
internet develop problems like and of adults. (8) True (9) False. Person indulging in
. selfie is not aware about the world around and the
risks. (10) False. Banks never ask our PAN / Credit
(11) unit has been newly launched in
Card/ debit card number on mobile phones. (11) True
police department.
(12) False. Yoga is not just limited to asanas and
(12) is the first state to start a separate pranayam but it includes discipline, balanced and
cyber crime unit. good food and meditation also.
(13) encourages children to take Q.1. (B) Choose and write the correct option:
education by helping them to improve their (1) Which of following mentioned factors are
health and lifestyle. important for good social health?
(14) Tobacco containing substances have (a) strong personality
effect on mouth and lungs. (b) having large number of friends
(15) helps to improve concentration in (c) trust in others (d) all of the above
the studies. (2) All of the following are accepted stress
Ans. ( 1) stress (2) nervous (3) IT ACT-2000 (4) social management techniques except .
health (5) Adolescent (6) Music (7) Unified (a) avoiding problem
Movement against Tobacco (8) Social health (9) Liquor (b) effective time management
(10) autism, selfishness (11) Cyber crime (c) relaxation (d) exercise
(12) Maharashtra (13) Salaam Mumbai foundation
Ans. (1) (d) all of the above (2) (a) avoiding problem
(14) carcinogenic (15) meditation
Q.2.1. Define the following:
Q.1. (A) 2. State whether the given statements are
(1) Piracy
True or False. Correct the false statement.
Ans. Misuse or illegal sale of the written literature,
(1) Meditation helps students to improve
software, photos, videos, music, etc. of others by
concentration in their studies.
obtaining it from internet or any other source is
(2) Addictive person can think rationally. called as piracy.
172 Master Key Science and Technology Part-2 (Std. X)

(2) Selfiecide (2) Child of your neighbour is addicted to tobacco

Ans. Person indulging in selfie, is not aware about the chewing.
world around and the risks is called as selfiecide. Ans.
(3) Social health (i) There can be carcinogenic effect of tobacco on
Ans. Social health can be defined as the ability of a mouth and lungs.
person to establish good relations with other (ii) I will explain regarding harmful effects to both,
person. parents and the child.
Q.2.2. Answer the following: (iii) This will help their child overcome the addition.
*(1) Do you recall the sudden closing of any cartoon I will help him to cultivate some good hobby to
serial of foreign origin being telecast on divert his mind from tobacco.
television. (Recall a little; Textbook Page no. 104) (3) Your sister has become uncommunicative. She
Ans. Yes, the closing of cartoon named ‘Shinchan’. prefers to remain alone.
(2) What is called as hacking of information? Ans.
Ans. Confidential information about government, (i) If my sister has become uncommunicative and
institute and companies, is obtained from prefers to remain alone which is an indication
internet with the help of computer programs or that she must be stressed with some worries.
other ideas and they are misused. This is called
(ii) As expressing our feelings with near and dear
as hacking of information.
ones help to relieve the stress, I will try to talk
(3) Which are the various ways that help us to to her. To divert the energy and mind towards
relieve stress? positive thinking I will advise her to foster her
Ans. Various ways of expression like establishing hobby.
communication with friends, peers, cousins,
(iii) I will do also advise her to take up yoga or
teachers and more importantly parents, noting
meditation.
down our feelings, expressing our feelings with
(iv) I will try to discuss this with my parents also so
near and dear ones help us to relieve stress.
that they can help her come out of the stress.
(4) What are laughter clubs?
(4) You have to use free space around your home
Ans. It is a newly popularized concept wherein, people
for good purpose.
come together in public places (park, garden)
and laugh loudly for a fixed duration of time to Ans.
relieve mental stress. (i) I will plant trees, flowering plants and make a
*Q.2.3. What will you do? Why? beautiful garden. I will also arrange for space for
outdoor games.
(1) You are spending more time in internet / mobile
games, phone, etc. (ii) I will see to it that it is not littered.
Ans. (iii) It will be a place where I can invite my friends
(i) Various physical problems like tiredness, and play games.
headache, insomnia, forgetfulness, tinnitus, joint (5) Your friend has developed the hobby of
pains and problems in vision may arise due to snapping selfies.
radiations of cell phone. Ans.
(ii) These radiations penetrate the bones of children
(i) Person indulging in selfie is not aware about the
more effectively than the bones of adults.
world around and the risks.
(iii) Hence, I will make a conscious attempt to not
(ii) I will advise my friend to stop this weird
spend more time in internet/mobile phones,
behaviour as practice of taking selfies has led to
games etc. I will cultivate some good hobby or
many deaths.
play sports and concentrate on my studies.
(iii) I will suggest him that the habit of taking selfies
(iv) I will even meditate to get rid of internet
many times a day is disturbing your personal,
addiction.
social and professional life.
Social Health 173

(iv) I will recommend him to develop some hobbies (i) Satisfying basic needs of a person. Food, Clothing,
like reading books or playing sports to help him Shelter, Medicines
get rid of this habit. (ii) Education
(6) Your brother studying in XII has developed (iii) Financial status
stress.
(iv) Social and physical conditions of the surrounding
Ans.
(v) Social environment of the surrounding
(i) Competition has increased in education,
(vi) Education and job opportunities
employment and business due to increaseing
(vii) Social safety
population.
(viii) Social treatment
(ii) As expressing feelings helps to relieve stress, I,
along with my parents will help my brother to (ix) Political conditions (views)
relieve his stress by talking and discussing with (x) Residential area
him. (xi) Water
(iii) I will also help him by giving him suggestions (xii) Toilets
about ways to cope up with studies and help him
(xiii) Transport facilities
with time management.
(xiv) Gardens
(iv) I will advise him to go for regular exercise, yoga
(xv) Play grounds
and meditation to improve his concentration and
relieve stress. (2) What changes occur in persons an continuous
usage of internet and mobile phones?
(v) I will explain him the importance of balanced
diet and good food to relieve stress. Ans.
(vi) Also, I will advise him to take regular breaks from (i) Various physical problems like tiredness,
studies and nurture a hobby which will help him headache, insomnia, forgetfulness, tinnitus, joint
to relieve stress and concentrate better in studies. pains and problems in vision may arise due to
radiations of cell phones.
Q.2.4. Give examples of each:
(ii) These radiations penetrate the bones of children
*(1) Hobbies to reduce stress
more effectively than the bones of adults.
Ans. Photography, reading, cooking, drawing,
(iii) Person continuously using the computers and
dancing.
internet becomes solitary.
*(2) Diseases endangering social health.
(iv) Chronic effect of such tendency is that they are
Ans. AIDS, T.B., leprosy and mental disorder.
not ready to help others in need and hence they
*(3) Physical problems arising due to excessive use also do not get help when in need.
of mobile phones.
*(3) Explain details on happening about blue whale
Ans. Tiredness, headache, insomnia, forgetfulness, game. (Recall a little; Textbook Page no. 104)
tinnitus, joint pains and problems in vision.
Ans.
*(4) Activities under the jurisdiction of cyber crime
(i) The Blue whale is a killer online game of
laws.
inflating proportions that nobody has reliably
Ans. Hacking of information, video piracy, sending encountered.
derogatory messages, cyber bullying, introducing
(ii) It is a sequence of online dares that participant
computer viruses, sending vulgar pictures,
must progressively engage in to get ahead.
exchange of information and phone number, etc.
(iii) These include etching a blue whale an your skin
are activities under the jurisdiction of cyber crime
and jumping off buildings.
laws.
(iv) There have been at least three reported suicides in
(5) Things which are addictive.
India of youth who were playing or had searched
Ans. Tobacco, alcohol, drugs, taking selfies.
for the game online.
*Q.3.1. Answer the following: (4) Write a note on Salam Mumbai Foundation.
(1) Which factors affect the social health? Ans.
Ans. Following are the factors affecting social health: (i) Salaam Mumbai Foundation runs programs
174 Master Key Science and Technology Part-2 (Std. X)

empower the children living in slum area in the

Then
field of education, sports, arts and business.
(ii) This organization encourages the children to
take education by helping them to improve their
health and lifestyle. Come
(iii) This trust has made some districts in Maharashtra for
completely tobacco-free through hard work. Study!

(iv) Since the year 2002, this organization is working

with various schools in urban and rural area for
making the society tobacco-free. Now
(v) This programme is being implemented with
the help of government in about 200 schools
in Mumbai and 14000 schools in the rest of
Maharashtra. Go to
(vi) The oath of freedom from tobacco is taken is play!
every school as per the government letter.
*Q.3.2. Answer the following questions:
*(1) Whether the incidence shown in the following
Fig. 9.2 Different Situations
picture is rational? Express you opinion. (Think;
Textbook Page no. 103) Ans.
(i) For over a period of time, there is a decline in the
time which children used to play out door games.
(ii) Children are staying indoors playing computer
games or spending time on mobile phones rather
than going outside and playing.
(iii) Research shows outdoor play is much more than
just fun. It is necessary to help kids be physically
and mentally fit and healthy.
(iv) Thus, in the above caricatures it is shown that in
1998 where the kids were spending more time
than needed outside playing. So, the mother at
that time used to forcibly take them in. But in
Fig. 9.1 An incidence today’s modern times, the mother has to make
Ans. her kid stay away from the gadgets and force
him/her to play outdoor games.
(i) The incidence shows that a woman is misbehaving
with a person who looks old and may be suffering *(3) Observe the images. Is it rational? Why? (Observe;
from some incurable or chronic disease. Textbook Page no. 104)

(ii) Misbehaving with or mistreating such person

will add to his/her sufferings.
(iii) So it is not at all rational to behave in this manner
rather we should have an approach to help such
persons. Taking care, talking with the old person
will help him to ease his suffering.
*(2) Two caricatures presenting the situations of the
year 1998 and 2017 about playing on playground
are given below. Observe those caricatures.
Express your opinion about arising of such
different situations. (Observe; Textbook Page no. 103) Fig. 9.3 Boy using cell phone while eating
Social Health 175

(iv) Thus, there is increase in news of death by

drowning in ocean, falling in deep valley or
under trains while taking the cell phone selfie.
*(6) There is increasing competition to upload the
videos of road accidents instead of helping the
victims. What is the mentality of such people?
(Question from Textbook Page no. 104)
Ans.
(i) Now a days there is a trend going on between
friends that who got many views / likes /
comments. To achieve and so they post accident
videos.
Fig. 9.4 Selfie on Road (ii) People are so engrossed in their virtual life that
Ans.
they are ignoring the humanity.
(i) In the first image, the boy is using cell phone
(iii) Thus, people are getting attached with virtual
while eating. It is wrong as it can affect proper
stuff and are least bothered about, what is going
digestion of food. Since the boy is focused on
on around them.
mobile, he will not be chewing the food well
before swallowing. He might mistakenly eat *(7) Why are the video-clips of parents threatening
something which he should not consume. or hitting the children not studying as per their
wish or domestic helpers beating the children
(ii) In the second image, there is a person taking selfie
are very common on social media nowadays?
on road. It is wrong as it can lead to accidents
(Question from Textbook Page no. 104)
and the person, may lose his life. For the sake of
safety, selfies should not be taken on places like Ans.
train/bus stop/ railway track, on a roller coaster, (i) Domestic violence against children has adverse
with wild animals, busty streets and high ways, effect on their physical as well as mental growth.
high cliffs and near water bodies. (ii) If video clips of parents threatening or hitting
*(4) Have you ever seen the persons inebriated the children not studying as per their wish
with drugs or liquor loitering on dirty or domestic helpers beating the children are
places? Whether such a pitiful condition of uploaded, the people doing such abuse will think
most intelligent human being is acceptable? twice before doing any such thing.
(Can you tell?; Textbook Page no. 103) *(8) Why do you wait for periods of music, P.T.,
Ans. drawing in the classroom? (Can you tell?; Textbook
(i) It is a pitiful sight and condition to see any person Page no. 106)
walking in public places inebriated with drugs or Ans.
liquor. (i) Learning music and drawing, listening to the
(ii) Drugs as well as liquor majorly affects the music, singing keeps us happy and drives away
nervous system and the control over the action of the stress.
a person is lost. (ii) Physical training improves discipline, interaction
(iii) Apart from the person being affected, the family and tendency of unity. Loneliness is driven away.
and vicinity is caused harm and gets distressed. (iii) Since these periods help us to get a break, drives
(iv) Hence, such a condition of human is not acceptable. away stress and loneliness, and keep us fit, we
*(5) Why is there increase in news of death by wait for these periods.
drowning in ocean, falling in deep valleys or *Q.3.3. Solve the following cross words:
under trains while taking the cell phone selfie? (1) Continuous consumption of alcoholic and
(Question from Textbook Page no. 104) tobacco-materials.
Ans. (2) This app may cause cyber crimes.
(i) Person indulging in selfie is not aware about the (3) A remedy to resolve stress.
world around and the risks.
(4) Requirement for stress free life.
(ii) Some people can go to the extremes to capture
the “perfect selfie” ignoring the dangers. (5) Various factors affect health.
(iii) Young people want to impress others and they (6) Art of preparing food items.
don’t even care about the dangers.
176 Master Key Science and Technology Part-2 (Std. X)

(ii) Communication helps to spread knowledge and

3 information among people.
5 6 (iii) Communicating helps people to express their
ideas and feelings, and helps us to understand
4 emotions and thoughts of others.
(iv) Importance of communication cannot be
2
underestimated.
(v) It also helps us to relieve stress.
(vi) We should learn how to communicate effectively
1 A D D I C T I O N
to make our lives better.
(3) Which are the various ways to minimize stress?
Ans. Ways to Minimize Stress:
(i) Joining a laughter club.
(ii) Communication with friends, peers, cousins,
teachers and parents, noting down our feelings,
expressing our feelings with near and dear ones
help us to relieve stress.
(iii) Fostering hobbies like material collection,
Ans. ( 1) ADDICTION (2) FACEBOOK (3) SINGING photography, reading, cooking, sculpturing,
(4) GOOD FOOD (5) SOCIAL (6) COOKING drawing, rangoli, dancing, etc. helps to divert
Q.4. Answer in detail: energy and mind towards positive energy.
(1) Which problems does the common man face (iv) Learning and listening to music, singing helps to
due to incidence of cyber crime? change the mindset and keep us happy.
Ans. Following problems are faced by common man (v) Regular exercising, massaging, visiting the spa
due to incidence of cyber crime: also helps to relieve the stress.
(i) Consumers are deceived by showing superior (vi) Deep breathing, Yogasanas, Yogic sleep,
items on websites but actually selling items of meditation, balanced and good food also help to
either inferior quality or impaired ones. impart positivity and relieve stress.
(ii) Bank transactions are done using PIN without the (vii) Time management, planning of our own duties
knowledge of consumers causing financial loss. and decision power are also effective ways of
(iii) Confidential information about government stress management.
institutes and companies is obtained from the *(4) What type of changes occurs in a home having
internet with the help of computer programs or chronically ill old person? How will you help to
other ideas and misused. This is called as hacking maintain good atmosphere?
of information. Ans.
(iv) Crimes like opening a fake account on Facebook (i) The quality of life of family member as well as of
and displaying false information and thereby chronically ill old person can be hugely reduced
teasing the girls or exploiting them financially. in terms of physical, psychological and social
(v) Piracy of written literature, software, photos, problems.
videos, music, etc. (ii) Family members experience emotions such as
(vi) Electronic media is also misused by sending worry, frustration and stress.
derogatory messages, spreading vulgar pictures (iii) The work life of family members is affected.
and inflammatory statements.
(iv) The family has to bear with the behavioral
(vii) Our personal information and phone numbers are disturbances in the patient.
spread through email, facebook and whatsapp
(v) There is financial pressure on the family due to
and reaches unwanted persons. This leads to
medical expenses.
malpractices like incoming of unnecessary
(vi) Meeting social workers, rehabilitation therapists,
messages. Some of such messages either impair
and physicians regularly can help the family
or shut down mobiles and computers.
members to take care of the ill old person.
(2) Explain the importance of good communication
with others. (vii) Taking care, talking with the old person
counselling the family members will not only
Ans.
ease his/her suffering but also help in maintaining
(i) Communication is the foundation of all human
good atmosphere at home.
relationships, it plays a vital role in human life.
Social Health 177

ASSIGNMENT - 9
Time : 1 hr. Marks : 20

Q.1. (A) Answer the following: (3)

(1) Fill in the blanks:
Laughter club is a remedy to drive away .................. .
(2) State whether True or False:
Persons continuously using internet become solitary.
(3) Give one example: Hobby to reduce stress.

Q.1. (B) Choose and write the correct option: (2)

(1) which of the following factors are important for good social health?
(a) Personality (b) Having large number of friends
(c) Trusting other (d) All the above
(2) All of the following are accepted stree management technique except .................. .
(a) avoiding problem (b) effective time management
(c) relaxation (d) exercise

Q.2. Answer the following: (Any 2) (4)

(1) What is hacking of information? (2) List the factors which affect social health.
(3) See the picture and answer the following questions.

(a) What do you think is seen in the picture?

(b) Is it an appropriate action ? Why ?

Q.3. Answer the following: (Any 2) (6)
(1) What will you do? Why?
Your friend has developed the hobby of snapping selfies.
(2) Is the action shown in the picture a sensible action? Explain.

(3) Write a short note on Salaam Mumbai foundation.
Q.4. Answer the following: (Any 1) (5)
(1) Explain the various ways to minimise stress.
(2) Which problems does the common man face due to incidences of cyber crime?
vvv
10 Disaster Management
CONCEPT MAP
(1)
Types of Disaster

Geophysical Biological Man-made

Geological Atmospheric Plant Animal Unpredictable Intentional

eg. Tsunami, e.g. Hot and e.g. Forest fire, e.g. Infectious e.g. Leakage of e.g. War, fire,
earthquake, Cold waves, destruction bacteria,viruses poisonous gas, bomb blast,
volcano, snow, storms, of water by cause diseases radiation of forced migration,
landslide, floods, draughts, aquatic weeds like cholera, atomic teasts, child labour, rape,
flooding etc. snowfall, hail and destruction malaria, plague unplanned
terrorism, etc.
strom, etc. of land by hepatitis; bites of accidents, etc.
common grass, poisons animals,
etc. etc.

(2) Nature and Scope of Disaster

3 Aspects

Phase of emergency Transitional Phase Reconstruction phase

(1) Research and reuses (1) Rehabilitation work (1) Construction of building
(2) Medical (2) Clearing debris (2) Eacilities like road and
(3) First aid (3) Restoring water supply water supply are restored.
(4) Restoring communication (4) Repairing roads (3) Setting life to normalcy
services. (5) Offering aid.
(5) Removing people from
affected area.

(3)
Emergency phase Warning phase

Rehabilitation phase Phases of disaster Pre disaster phase

Recovery phase Reconstruction phase

(4)
Disaster Management

Pre-disaster management Post disaster managment

(1) Identification of pre-disaster areas. (1) Providing all types of necessary
help to victims of disaster.
(2) Collection, information about the identity (2) Participation of preferably local people
of disaster and probable sites of disaster. saved from disaster.
(3) Getting special training for disaster (3) Categorization of the help material
management received from control centre
(4) Increasing awareness about disaster management (4) Being prepared for disaster

(178)
Disaster Management 179

(5) National disaster management authority

Other Social / private

Chairman : Prime Minister

Organizations providing
precautionary warming

organization
State disaster management authority
Chairman : Chief Minister

District disaster management authority

Chairma : Collector

Taluka disaster management authority

Chairman : Tahsildar
System involved in
actual rescue and
Village level Committee
General public rehabilitation work
Chairman : Sarpanch

Points to Remember:
• Various dangerous events occurring many times in the environment are called as disasters.
• United Nations has defined the disaster as ‘sudden event that leads to the huge loss of life and property’.
• As the disasters occur suddenly, they cannot be predicted. Hence, precautions are not possible. Reasons
behind each disaster are also different.
• Period of each disaster is also not same. Some disasters are short term whereas some are long term.
• Various areas of life like economic, social, cultural, political, law and administration etc. are affected by
disaster.
• Disasters making the impact for long duration are those whose after effects are either severe or severity
increases with time.
• Cyclones, earthquakes, famines, floods, droughts, etc. are some of the disasters.
• Disasters are classified into following three types: (i) Geophysical (ii) Biological (iii) Man-made.
• Disasters definitely affect the economy of the nation.
• An effect of disaster on social leadership is that if local leadership is not strong enough, citizens become
confused.
• Taking into consideration the scope of disaster, some of the important facts must be thought over, as
follows: • Pre-disaster phase • Warning phase• Emergency phase • Rehabilitation phase • Recovery phase
• Reconstruction phase
• The important aspects of disaster are -
(i) Phase of emergency (ii) Transitional phase (iii) Reconstruction phase
• There is a great threat to human being in the form of atomic energy plants. The risk of radiation leakage is
increasing due to carelessness.
• Disaster management is either prevention of disasters or making arrangements to face it or at least achieve the
abilities to face them. There is a close relationship between disaster management and public participation.
• Though avoidance of natural disaster is impossible, loss out of it can be minimized. However, man-made
disasters can be avoided.
• Helping each other in the crisis of disaster is our ethical responsibility.
• Mock drill is a practice to check the preparedness of facing the disaster as early as possible within includes
the demonstrations like extinguishing the fire, rescuing the people trapped at higher floors of buildings,
rescuing the persons whose clothing have caught fire, etc.
• The disaster management schemes should be changed with respect to location, time and nature of the
disaster.
180 Master Key Science and Technology Part - 2 (Std. X)

(2) Atomic tests, snow fall, war, bomb blast.

MASTER KEY QUESTION SET - 10
Ans. Snow fall - Others are man made disasters
Q.1. (A) 1. Fill in the blank and rewrite the statement: whereas snowfall is a geophysical disaster.
(1) Spreading of weeds is ............. type of disaster. (3) Terrorism - earthquake, cyclones, flooding.
(2) At the time of disaster, the ............. leadership Ans. Terrorism - Others are geophysical disasters
plays very important role. whereas terrorism is a man-made disaster.
(3) The disaster management act has been established (4) Hand gloves, shampoo, soap, medicated cotton.
in ............. . Ans. Shampoo - Others are tools of first aid kit.
(4) The rehabilitation work starts in ............. phase. (5) Transitional phase, reconstruction phase, phase
(5) Various dangerous events occur many times in of emergency, disaster management.
the environment are called ............. . Ans. Disaster management - Others are aspects of
(6) ............. is arranged on disaster of fire in various disaster.
schools by the fire fighters. (6) Tahsildar, general public, collector, chief minister.
(7) The helpline number of Disaster Control Unit is Ans. General public - Others are disaster management
............. . authority
(8) Collapsing of houses, developing cracks in land (7) Resurgence, restoration, redemption, repetition.
are some of the effect of ............. . Ans. Repetition - Others are main aspects of disaster
(9) Search and rescue operations take place during management cycle.
............. phase. (8) Earthquake, forest fire, fungal disease, weed.
(10) Facilities like roads and water supply are restored Ans. Earthquake - Others are biological disorders
in ............. phase. whereas earthquake is a geophysical disorder.
(11) Most of the disasters have occurred in the ............. (9) 100, 101, 201, 108.
continent and ............. ocean.
Ans. 201 - Others are helpline numbers.
(12) Radiation leakage occured after a blast in atomic
(10) Search operations, first aid, migration, regulating
energy plant at ............. in Russia.
water supply.
(13) ............. in the Chairman of the State disaster
Ans. Regulating water supply - Others are actions of
management authority.
phase of emergency whereas restoring water
(14) ............. in the Chairman of the District disaster supply is an action of transitional phase
management authority.
(11) Bomb blast, tsunami, cyclone, flood.
(15) It is necessary to have material for ............. with
Ans. Bomb blast - Others are natural disaster and
us.
Bomb blast in man-made.
(16) Cyclone is a ............. type of disaster.
(12) Cotton, antiseptic, petroleum jelly, antigens.
(17) The headquarter of the National Disaster
Ans. Antigens - Others are materials in the first aid kit
Response Force is located in ............. .
antigen is not.
Ans. (1) biological (2) local (3) 2005 (4) transitional
Q.1. (A) 3. Complete the analogy:
(5) disasters (6) Mock drills (7) 108 (8) earthquake
(1) Cyclones : Atmospheric :: Earthquake :
(9) emergency (10) reconstruction (11) Asian, Pacific
Ans. Geophysical
(12) Chernobyl (13) Chief Minister (14) Collector
(15) first aid (16) Natural (17) Delhi (2) Volcano : Geological :: Bomb blast :
Ans. Man-made
Q.1. (A) 2. Find the odd one out:
(3) Tsunami : Geological :: Hail storm :
(1) Volcano, earthquake, land-slides, cyclones.
Ans. Atmospheric
Ans. Cyclones - Others are geological disasters
(4) Pests : Animals :: Weeds :
whereas cyclone is an atmospheric disaster.
Ans. Plants
Disaster Management 181

(5) Chief Minister : State authority : : Prime Minister Q.1. (A) 5. Match the columns:
:
(1) Column ‘A’ Column ‘B’
Ans. National authority
(1) Redemption (a) Link between emergency
(6) Search and response operations : Phase of measures and national
emergency :: Clearing of debris : progress
Ans. Transitional phase (2) Restoration (b)  Plan for minimizing the
(7) 101 : Fire fighting force :: Disaster control unit : damage.
(3) Resurgence (c) Plan is prepared to
Ans. 108 minimize destruction.
(8) Bhopal Tragedy : 1984 :: Landslide in village (4) Preparation (d) Link between measures
Malin : after disaster and national
development.
Ans. 2014
Ans. (1 - b); (2 - d); (3 - a); (4 - c)
(9) Japan : Hiroshima :: Russia :
(2) Column ‘A’ Column ‘B’
Ans. Chernobyl
(1) War (a) Atmospheric disaster
Q.1. (A) 4. Write the difference in one sentence.
(2) Volcano (b) Biological disaster
(1) Transitional phase and Reconstruction phase.
(3) Cyclones (c) Geological disaster
Ans. Transitional phase:- Rehabilitation work starts
(4) Infectious virus (d) Man-made disaster
after the subsidence of any type of disaster.
Reconstruction phase:- People reconstruct their Ans. (1 - d); (2 - c); (3 - a) (4 - b)
buildings and facilities like roads and water (3) Column ‘A’ Column ‘B’
supply are restored. (1) 102 (a) Fire fighting force
(2) Pre-disaster management and Post-disaster (2) 101 (b) Police
management. (3) 108 (c) Ambulance
Ans. Pre-disaster management:- This includes the (4) 100 (d) Disaster Control Unit
complete preparation and planning to prevent
Ans. (1-c); (2-a); (3-d); (4-b)
any type of disaster.
Post-disaster management:- Providing all types (4) Column ‘A’ Column ‘B’
of necessary help to victims of disasters. (1) Tahsildar (a) District disaster
management
(3) Redemption and Restoration.
(2) P
 rime Minister (b) V
 illage level committee
Ans. Redemption:- Plan for minimizing the damage to
(3) Sarpanch (c) State disaster
the society and country.
management
Restoration:- This is an important link between
(4) Collector (d) National disaster
measures after disaster and national development.
management
(4) Response and Resurgence.
(e) Taluka disaster
Ans. Response:- Response to the disaster is to be given management
immediately after the incidence.
Ans. (1-e); (2-d); (3-b); (4-a)
Resurgence:- Resurgence is an important link
between emergency measures and national (5) Column ‘A’ Column ‘B’
progress. (1) Phase of emergency (a) Takes long time
(5) Phase of emergency and Reconstruction phase. (2) Reconstruction phase (b) After the subsidence
of any disaster.
Ans. Phase of emergency:- Important character of this
(3) Transitional phase (c) Search and rescue
phase is that maximum lives can be saved by
operations
quick actions.
(d) Measures before
Reconstruction phase:- People construct their
disaster
buildings and facilities like roads and water
supply are restored. Ans. (1-c); (2-a); (3-b)
182 Master Key Science and Technology Part - 2 (Std. X)

Q.1. (A) 6. State whether the following statements *(2) Which are the two main types of disasters? (Can
are true or false. Correct the false statement: you tell; Textbook Page No. 109)
(1) Disaster leads to huge loss of life and property. Ans. The two main types of disasters are natural and
(2) Worker’s strike is a natural disaster. man-made disasters.
(3) Bomb blast is a geophysical disaster. *(3) What is first aid?
(4) Disaster Management Act was passed in our (Can you tell; Textbook Page No. 116)
country in 2005. Ans. First aid is emergency care or treatment given
(5) At the district level, Tahsildar is responsible for to a sick or injured person until proper medical
disaster management. treatment is available.

(6) Reconstruction phase takes very long time for *(4) What are effects produced on health due to
proper reconstruction. disasters?

(7) Radiation leakage occurred after a blast in Malin. Ans. Effects on the health are
(8) We should not touch any unclaimed object. (i) injuries (ii) emotional and mental stress (iii)
outbreak of epidemics (iv) mortality of victims.
(9) Mock drill creates fear among people.
(5) List down reasons due to which conditions of
(10) Gravity of disaster can be estimated in the phase
instability in the country arise.
of emergency.
(11) Earthquake, volcano, tsunami are atmospheric Following are the reasons due to which instability
disorders. in the country arises:
(12) Maximum lives can be saved by quick actions Ans. (i) economy inequality (ii) social and religious
during phase of emergency. differences (iii) terroristic and social difference etc.
(13) Gravity of the disaster can be estimated in (6) Which disaster occured in village Malin in 2014?
reconstruction phase. Ans. In 2014, village Malin is Tal, people faced a huge
(14) Rehabilitation of the victims is an important landside in district Pune.
aspect of reconstruction phase.
Q.1. (B) Choose and write the correct option:
(15) Disasters have been increased after World War-II.
(1) Wild animal attack is type of disaster.
(16) Production and use of harmful chemicals is
(a) atmosphere (b) migration
common in developed countries.
(c) geological (d) biological
(17) It is possible to avoid natural disaster.
(2) The chairman of village level committee is
Ans. (1) True (2) False. It is man-made disaster. (3) False.
.
It is man-made disaster. (4) True (5) False. At the
district level collector is responsible for disaster (a) Sarpanch (b) Chief Minister
management while Tahsildar at Taluka level. (6) True (c) Collector (d) Prime Minister
(7) False. Radiation leakage blast occured in Cherobyl (3) Tsunami is a type of disaster.
while a huge landslide resulted in a disaster in Malin.
(a) biological (b) man-made
(8) True (9) False. Mock drill helps to check the efficiency
of the system. (10) True (11) False. Earthquake, volcano, (c) geological (d) plants
tsunami are geological disorders. (12) True (13) False. (4) The important link between measures after
Gravity of the disaster can be estimated in phase of disaster and national development comes under
emergency. (14) False. Rehabilitation of the victims .
is an important aspect of transitional phase. (15) True (a) preparation (b) restoration
(16) False. Production and use of harmful chemicals is
(c) resurgence (d) impact of disaster
banned in developed countries. (17) False. It is impossible
to avoid natural disaster. (5) The disaster management act passed in our
Q.1. (A) 7. Answer the following in one sentence: country in .

*(1) What is a disaster? (Can you recall; Textbook (a) 2004 (b) 2007 (c) 1998 (d) 2005
Page No. 109) (6) In 2014, there had been a huge in the
Ans. A disaster is a sudden event that leads to huge village Malin.
loss of life and property. (a) cyclone (b) volcano eruption
(c) landslide (d) bomb blast
Disaster Management 183

(7) Disasters definitely affect the of the (a) Phase of emergency : Important character of
nation. this phase is that maximum lives can be saved
(a) economy (b) geography by quick actions during this phase only. Various
(c) health (d) pollution actions like search and rescue operations, medical
(8) The disaster management schemes should be assistance, first aid, restoring communication
changed with respect to of the services, removing the people from affected area
disaster. are expected in this phase. Gravity of disaster can
be estimated in this phase only.
(a) nature (b) culture (c) depth (d) day
(9) In Maharashtra is in action through (b) Transitional phase : Rehabilitation work starts
State Reserve Force. in this phase, after subsidence of any type of
disaster. It includes clearing of debris, restoring
(a) WHO (b) NDRF (c) NCC (d) MCC
water supply, repairing roads etc. so that it helps
(10) Radiation leakage occurred after a blast in atomic to bring normalcy in public life.
energy plant of in Russia.
(c) Reconstruction phase: People reconstruct
(a) Moscow (b) Hiroshima
their buildings and facilities like roads and
(c) Syberia (d) Chernobyl
water supply are restored. Farming practices
Ans. (1) (d) biological (2) (a) Sarpanch (3) (c) geological are restarted. However, it takes a long time for
(4) (b) restoration (5) (d) 2005 (6) (c) landslide reconstruction.
(7) (a) economy (8) (a) nature (9) (b) NDRF (10) (d)
*(3) Mock Drill
Chernobyl.
OR
Q.2.1. Write short notes:
Mock Drill is useful - Give reason.
*(1) Disaster Management Authority.
Ans.
Ans.
(i) Mock Drill is a practice to check the preparedness
(i) In case of disaster management, there should be
of facing the disaster as early as possible.
an attempt to minimize the losses.
(ii) Virtual or apparent situation of disaster is created
(ii) Authority has been established at the level of the
to check the reaction time for any type of disaster.
Government.
(iii) Mock drill helps to check the efficiency of the
(iii) Disaster Management Act, 2005 has been passed
system prepared for disaster redressal.
in our country.
(iv) Mock Drill is observed and performed under
(iv) At the district level, district collector is responsible
trained personnel who check execution of plan
for disaster management and implementation of
rehabilitation schemes. designed for disaster redressal.
(v) Collector is responsible for planning, co- (v) It is arranged in various schools by the fire
ordinating and controlling the implementation fighters to create awareness during fire.
of rehabilitation programme, gives out necessary (vi) It includes demonstrations like extinguishing
instructions and reviews the entire system. fire, rescuing the people trapped at higher floors
(vi) District collector is also responsible for designing of buildings, rescuing the persons whose clothing
the schemes for each district, separately for each have caught fire, etc.
type of disaster and getting those sanctioned (vii) Such activities are also organised by police force
from state level authorities. and voluntary organizations.
(vii) District control unit is established immediately (4) Objectives of Mock Drill
either after the impact of disaster or getting
intimation about it. It receives information about Ans. Following are the objectives of Mock Drill.
various aspects of disaster, keeps continuous (i) Evaluating the response to the disaster.
contact with various agencies. (ii) Improving the co-ordination between various
*(2) Nature and Scope of disaster Management. departments of disaster control.
Ans. (iii) Identification of own abilities.
(i) Taking into consideration the nature and scope of (iv) Checking the competency of the planned actions.
disaster, three aspects of disaster are important (v) Improving the ability of quick response.
for common citizens. (vi) Identifying the possible errors and risks.
184 Master Key Science and Technology Part - 2 (Std. X)

*(5) Disaster Management Act: 2005 (iv) Its headquarter is in Delhi and it is in action all
Ans. over the country with the help of army.
(i) National Disaster Response Force has been (v) In Maharashtra, National Disaster Response
established as per the Disaster Management Act Force is in action through State Reserve Police
2005. Force.
(ii) Divisions of these forces are working in the army. (vi) Personnel of this force have substantial
contribution in rescue work in disasters like
(iii) Overall 12 divisions are working in the country.
cyclones, cliff-sliding, building collapse, etc.
Q.2.2. Complete the flow chart:
*(1) Complete the chart as per the objectives of first aid. (Complete the chart; Textbook Page No. 117)
Ans.
Remove the cause which
resulted in damage Prevention of death Relieving the pains

Preventing deterioration Cover the wound

of condition of victim of Objectives of First Aid immediately
disaster

Breathing should be Attempt to improve

Saving lives brought back to normal the condition

(2) Complete the following chart with reference to pre-disaster management.

Ans. Identifying the Properties of pre- Increasing awareness
pro-disaster disaster management about disaster
areas management

Collecting the information Getting special

about the intensity of disaster training for disaster
and probable sites of disaster management

(3) Complete the following concept map for phases of disaster.

Ans. Emergency phase Warning phase

Rehabilitation phase Phases of disaster Pre disaster phase

Recovery phase Reconstruction phase

Q.2.3. Distinguish between:

(1) Pre-disaster management and Post-disaster management
Ans. Pre-disaster management Post-disaster management

(i) Identifying the pre-disaster areas. (i) Providing all types of necessary help to victims of disaster.

(ii) Collecting the information about the intensity (ii) Participation of preferably local people saved from
of disaster. disaster.

(iii) Getting special training for disaster (iii) Categorization of the help material received from
management. control centre.

(iv) Increasing awareness about disaster management. (iv) Performing rescue operations and restorations.
Disaster Management 185

Q.2.4. Answer the following: *(6) Depending upon above information, explain the
*(1) Identify the type of disaster. various effects of the disaster of railway accident.
(a) Terrorism (b) Soil erosion (c) Hepatitis (d) (Use your brain power; Textbook Page no. 111)
Forest fire (e) Famine (f) Theft Ans.
Ans. (i) Injuries or death of victims.
(i) Terrorism and theft are man-made disasters. (ii) Possible environmental damage - chemical
(ii) Hepatitis and forest fires are biological disasters. spillages, spillage of flammable substances.
(iii) Famine and soil erosion are geophysical disasters. (iii) Destruction of public property.
*(2) Which disasters have you experienced in your (iv) Financial losses.
area? (Can you recall, Page No. 109) (v) Collapse of communication system.
Ans. I have experienced disasters like flood, theft,
(vi) Disruption of rail traffic.
motor accident, fire due to electric short circuit,
electric shock, injuries during fighting in my area. (vii) Transport of commodities collapses.
(viii) Shortage of beds in hospital.
*(3) What are the effects of that disaster on local and
surrounding conditions? (ix) Emotional and mental stress to victims and
(Can you recall, Textbook Page No. 109) relatives.
Ans. *(7) Which are the effects of dry famine? (Can you
(i) It causes loss of life and property. recall; Textbook Page no. 110)
(ii) Spread of epidemics. Ans.
(iii) Various areas of life like economic, social, (i) Scarcity of water.
cultural, political, law and order, administration (ii) No agricultural production.
etc. are affected by it. (iii) No water for drinking.
*(4) Which are the destructive effects of flood? (Can
(iv) Scarcity of food and other useful commodities.
you recall, Page No. 110)
(v) Biodiversity will be in danger.
Ans.
*(8) Which are the destructive effects of Earthquake?
(i) Villages get submerged in water.
(Can you recall; Textbook Page no. 110)
(ii) Loss of life and property.
Ans.
(iii) Roads, bridges, farms, automobiles are destroyed.
(i) Collapse of houses,
(iv) Animals are killed and more insects infest the
affected area leading to imbalance of ecosystem. (ii) Loss to life and property.
(v) Chemicals and hazardous substances get mixed (iii) Debris and victims under the debris.
with water, polluting the whole area. (iv) Hampered communication.
*(5) What will be the effect on yourself and (v) Spread of epidemics.
surrounding, if any accident-like disaster occurs (vi) Economy is affected.
during the sports on playground or in school?
*(9) What is forest fire? What is its effect on
(Lets Think; Textbook Page no. 111)
environment?
Ans.
(Can you recall; Textbook Page no. 110)
(i) All the students including me will be under
mental stress and anxiety. Ans. It is a natural disaster found in some forests
where due to rise in temperature suddenly dry
(ii) Teachers will be under stress.
plant matter catches fire.
(iii) School functioning and education will be
temporarily disrupted. Effects:-

(iv) Anger of people against School Management, if (i) Trees get burnt.
the disaster is not handled properly. (ii) Plants and animals die.
(v) Analysis by school management on the cause of (iii) Adjacent agriculture practices are affected.
the accident in playground in school. (iv) Loss of bio-diversity.
(vi) It will affect children’s ability to perform well in (v) Creates environmental hazards like pollution.
exams.
186 Master Key Science and Technology Part - 2 (Std. X)

Q.3.1. Answer the following: (vii) Emergency numbers to be on every floor and
*(1) Effective disaster management makes us well easily visible.
prepared for future. Explain why it is said like (4) State precautions taken for insect bite.
that.
Ans. Insect bite generally causes the following
Ans. symptoms:
(i) Disaster Management is achieving or time to (i) Swelling, itchiness, blistering, redness.
time improving the ability to face the disasters
through scientific and careful observations and (ii) If there is an allergic reaction or dizziness then,
analysis of data. the doctor should be consulted immediately.
(ii) It involves collecting the information about (iii) Otherwise, wash the affected area with soap and
intensity of disaster and probable sites of disaster apply cold compress.
through predictive intensity maps and hazard (5) How does stampede happen?
maps respectively.
Ans.
(iii) It also includes getting special training for
disaster management. (i) Stampede is an uncontrolled running as an act of
(iv) Preparedness is a plan chalked out so as to get mass impulse by a crowd of people who think
the quick response from general public and that they are in danger.
administration. (ii) People run over others in the crowd to save
*(2) On the basis of structure of disaster - themselves in a panic.
management authority, form the same for your (iii) Mock drills can be very useful in teaching people
school. of how to react and evacuate in such situation
Ans. without harming others.
School Trust disaster management authority (6) How to treat fires caused due to short circuits?
chairman: Secretory of the management Ans.
(i) Do not use water for such fires, instead use fire
School disaster management authority chairman: extinguishers or fire blankets.
Principal
(ii) Electric power should be turned off and fire
brigade should be called immediately.
School section disaster management authority
(iii) Now-a-days, fires have become very common in
chairman: Vice Principal/Supervisor
high rise building in cities.
(iv) Regular wiring check by electrician should be
Class disaster management authority chairman :
Class teacher/Subject teachers/ Class monitor done.
(7) How can we prevent the spread of an epidemic
(3) Which different aspects of disaster management
at an individual level?
would you check for your school? Why?
Ans.
Ans. Following are the things that can be checked:
(i) Wash your hands often
(i) First aid box to provide first aid to victims of
injuries. (ii) Get vaccinated

(ii) Fire extinguisher to extinguish fire in case of (iii) Disinfect your home
emergency. (iv) Avoid junk street food and boil your drinking
(iii) Source of pure water for drinking if people are water.
stuck up. (v) Do not share your personal belongings with
(iv) Stretcher and Wheel chair to carry children to others.
hospital.
(vi) Consult your family doctor / physician if you
(v) Emergency exits are clear for evacuation in case
of any disaster. note any signs / symptoms of disease.
(vi) Practice of Mock Drills at regular intervals.
Disaster Management 187

Q.3.2. Suggest measures for the following: Ans.

*(1) Write down the reasons, effects and remedial (i) In the given diagram, ‘the students of the school
measures taken for any two disasters today are the future citizens of the country’ is the
experienced by you. theme and the awareness program is carried out
Ans. (1) Disaster : Bus fell from the overbridge into the to develop and nurture good habits.
flowing river.
(ii) Students carrying banners with slogans will
Causes:
encourage them to follow good habits.
(i) The bridge had become weak.
(ii) The bridge was not repaired earlier despite of (iii) Through this campaign students and community
threat of falling down. are oriented with awareness about their
(iii) The driver was driving bus at a reckless speed behaviour and role in the society.
and so he lost control over it. (iv) ‘Cleanliness and health always co-exist.’ This
Effects : banner wants to tell them the importance of
(i) Some passengers died, drowned and some of cleanliness for their healthy life.
them were severely injured.
(ii) The wall of the bridge got damaged. (v) ‘Give up the addiction and stay happy’. This
Remedial Measures : banner intends the students to be aware of
(i) Villages residing near the river rushed for help. addictions that people face and advise us to give
(ii) Survivors were given first aid immediately and up bad habits for good life.
were rushed to near-by hospitals. (vi) We should follows strict traffic rules if we need to
(iii) The Collector, social organizations came to the avoid accidents on roads.
accident spot and provided help.
(3) Some symbols are given below. Explain those
(2) Disaster : Accident of a four wheeler on the road.
symbol. Which disasters may occur if those
Causes:
symbols are ignored?
(i) Overspeeding of the vehicle.
(ii) Driver was talking on his cellphone while driving (i) (ii) (iii)
and suddenly lost control over the vehicle.
Effects :
(i) Persons in the vehicle got severely hurt.
(ii) Driver died on the spot.
(iii) Passengers did not use seat-belt, hence the
(iv) (v) (vi)
injuries were severe.
(iv) Vehicle caught fire after banging on the nearby
shop.
Remedial Measures :
(i) Victims were immediately taken in an ambulance (vii) (viii) (ix)
to nearby hospital after providing first aid.
(ii) Police were informed.
(2) Under the diagram and explain the concept.

Fig. 10.2
Ans.
(i) Toxic or irritant : If toxic or harmful chemical or
gas is carried through cylinders.
If ignored can cause leakage and lead to severe
damage.
(ii) Danger: If there is a danger to life, this symbol is
used. If ignored, can cause loss of life.

Fig 10.1
188 Master Key Science and Technology Part - 2 (Std. X)

(iii) Harmful for aquatic life: Chemical effluents if Ans.

left in water can cause loss of aquatic life. (i) Here the disaster is fighting between children.
(iv) Dangerous for health: Specially for tabacco and (ii) There may be abusive language used and can
alcohol. If ignored, can cause cancer. lead to noise pollution. Also, it can lead to serious
(v) Material causing skin corrosion / burns: injuries.
Corrosive to metals. If ignored can cause skin (iii) We will stop them immediately and separate
corrosion. them.

(vi) Oxidiser : Contact can cause damage to metals. (iv) Understand the root cause of quarrel and guide
them accordingly.
(vii) Inflammable: If any highly inflammable material
(v) We will try to explain to them the importance of
is carried through a vehicle, then this tag is used.
friendship.
If ignored, can cause fire.
(vi) If anybody is hurt first aid should be provided.
(viii) Explosive material: If a vehicle is carrying
explosive material then this symbol is used. If (c)
ignored, can cause explosion.
(ix) Gas is stored under pressure. If ignored can
cause gas leakage and damage.
*(4) Following are the pictures of some disasters. how
will be your pre and post-disaster management
in case you face any of those disasters?
(a)

Fig 10.5
Ans.
(i) The disaster here is heavy rains and flooding.
(ii) To prevent water logging we should keep man-
holes open for drainage.
Fig 10.3
(iii) Rescuing people from the water logged areas by
Ans.
using ropes, boats etc.
(i) The disaster is a leakage of cooking cylinder gas.
(iv) Temporary shelter should be given to effected
(ii) This may cause suffocation, difficulty in breathing people. Essential commodities should be
and can lead to fire.
provided.
(iii) Open the door and windows, switch off electric
(v) Electric supply should be restored at the earliest.
supply and close the cylinder knob.
(d)
(b)

Fig 10.4
Fig 10.6
Disaster Management 189

Ans. Ans.
(i) The disaster is a ‘Cyclone’ Fig. (a) is disaster of earthquake.
(ii) Forcast of the approaching cyclone can be helpful Precautions during earthquake:
in evacuating the main areas of the disaster.
(i) Do not panic. Take shelter under a table to protect
(iii) There may be incidence of uprootment of trees,
yourself.
building collapse etc.
(iv) Rescue operation for the victims should be (ii) Stay from bookcase or furniture that can fall on
immediately arranged. you.
(v) Temporary shelters should be given to the (iii) Stay away from windows.
victims. (iv) If you are in bed, hold on and stay there, protecting
(5) Following are some pictures of disasters. Which your head with a pillow.
precautions would you take during those
(v) If you are outdoors, find a clear spot away from
disasters?
buildings, trees, electric poles and wires.
(vi) If you are in a car, slow down and drive to a clear
place. Stay in the car until the shaking stops.
Fig. (b) is disaster of fire.
Precautions during fire:
(i) Remain calm
(ii) Feel if the door handle is hot, before exiting.
(iii) Close the door behind you to keep the fire from
spreading.
Fig. 10.7 (a)
(iv) If your clothes catch fire: stop, drop and roll.
(v) Cover yourself with a woollen blanket.
(vi) Do not use elevators to come down from a
building.
(vii) Immediately pull the nearest fire alarm.
(viii) If there is smoke in the air, stay close to the ground
to reduce inhalation.
(ix) Help to evacuate persons with special needs.
Fig. 10.7 (b) (x) Once clear and away from danger, call Fire
Fighting Force on number 101.
Fig. (c) is disaster of Snake bite.
Precautions during Snake-bite:
(i) Move the person beyond striking distance of the
snake.
(ii) Have the persons lie down with wound levelled
below the heart.
(iii) Keep the person calm and at rest, remaining as
still as possible to keep venom from spreading.
(iv) Cover the wound with loose, sterile bandage.
(v) Tightly wrap a bandage two to four inches above
Fig. 10.7 (c) the bite to reduce the flow of venom.
(vi) Call for medical help immediately.
190 Master Key Science and Technology Part - 2 (Std. X)

*(6) Give the reference of following pictures and can be made using bamboos, blanket etc.
explain importance of each of those in disaster (b) Artificial breathing: If the victim has
management. Which are other such activities? difficulty breathing, the head should be
held in a backward sloping position or the
chin should be raised so that the respiratory
passage remains open.
If breathing has stopped, the victim should
be given artificial ventilation by mouth to
(a) (b) mouth resuscitation.
(c), (d), (e) Method used by the fire-brigade to
transport the victim on shoulder.
(f) Human crutch method.
If one of the legs is injured, the victim
should be supported with minimum load
on the injured leg.
(c) (d)
Other activities:
(i) Other methods of transport like cradle method,
carrying piggy back, pulling or lifting method,
carrying on four-hand chair or two-hand chair
can be used to transport victims of any disaster.
(ii) If the victim is unconscious, then after giving
mouth to mouth respiration twice, the heart
(e) (f)
should be pressed down hard by pressing the
chest with both the palms. These two actions
Ans.
should be repeated alternately about 15 times.
(a) - Use of stretcher for transport of victim.
This is called cardio pulmonary resuscitation
In an emergency, if a conventional stretcher (CPR). It helps to bring circulation back to normal.
is not available, then a temporary stretcher

*(7) How can disasters be classified depending upon various criteria? (Can you tell; Textbook Page no. 110)
Ans.
Types of Disasters

(Geophysical) (Biological) (Man Made)

Geological Atmospheric Plant Animal Unknown International

Ex. Earth Ex. Hot and Ex. Forest fire, Infectious War, fire,
Poisonous
quake, cold waves, viruses,
fungal disease gases, bomb blast,
bacteria
volcano, snow-storms, spreading atomic forced
(cholera,
tsunami, snow fall, (Blister), weed, malaria, test. migration,
land-slides, cyclones, hail (aquatic, carrot hepatitis, unplanned terrorism
land-fall, storm, drought, grass, common plague), action
erosion, flood, meteorite grass) insects, bite accident.
oil alkalization fall, effects of of poisonous
animals, etc.
flooding, sun spots in
etc. climate, etc.
Disaster Management 191

*Q.3.3. (1) Write the symptoms, effect and remedial measures.

Disaster Symptoms Effects Remedial measures

(1) Motor accident (i) Damage to vehicle (i) Injured passengers (i) Speed Maintenance
(ii) Travellers are hurt (ii) Damage to vehicle (ii) Avoid overtaking
(iii) Death of a driver or (iii) Not to drink and drive,
passenger (iv) Wear seat-belts,
(2) Land-slide (i) Soil erosion (i) Roads blocked (i) Fencing and putting nets
(ii) Land-slide (ii) Loss and damage to (ii) Construction to prevent
vehicles landslide
(iii) People may die or get (iii) Cement coating
injured
(3) Forest Fire (i) Rise in temperature (i) Trees are burnt (i) Try to extinguish fire as
early as possible.
(ii) Fire may spread (ii) Loss of agricultural
across crops
(4) Theft (i) Cash and articles loss (i) Monetary loss (i) Take care of belongings
(ii) Faulty bank transaction (ii) Psychological effect (ii) Preserve the material
(iii) Piracy (iii) Proper security measures
(5) Riots (i) Mob (i) Noise pollution (i) Establish root cause of riots
(ii) Shouting slogans (ii) Loss of property (ii) Establish communication
(iii) Stone pelting (iii) People get injured (iii) Curfew
(iv) Fires (iv) Resolve the problem
(6) War (i) Encroachment (i) Life gets disturbed (i) Prohibit encroachment
(ii) Crossing LOC (ii) Loss of young soldiers (ii) World wide efforts
(iii) Firing (iii) Economic loss
(7) Epidemic (i) Economic loss (i) People fall victim (i) Destroy vectors
(ii) Disrupted work (ii) Diseases spread (ii) Maintain cleanliness
schedules
(iii) Diseases (iii) Timely treatment
(8) Water shortage (i) Reduced pressure (i) Pure water not (i) Save water
available
(ii) Alternate days supply (ii) Shortage of water
(ii) Use water safely
of water
(iii) Turbid water supply (iii) Spread of disease due (iii) Recycle water
to turbid water
(iv) Rain water harvesting
(9) Pest (i) Crop gets destroyed (i) Economic loss for the (i) Spray suitable insecticide
farmers and pesticide
(ii) Plantation get spoilt (ii) Price of fruits, vegetables,
grains increase
(10) Flood (i) Heavy rains (i) Heavy rains at the (i) Clean and clear blockage
time of high tide in drains
(ii) Drainage blocked (ii) Traffic disturbed (ii) Rescue people
(iii) Causes accidents
192 Master Key Science and Technology Part - 2 (Std. X)

(11) Famine Drought (i) No rains (i) Cracks in the land (i) Rain water storage
(ii) Excessive rains (ii) Spread of diseases (ii) Clean all nallahas
(iii) Vaccination programme
(iv) Provide necessary help
for victims.
Q.3.4. Observe the pictures of various disasters given Ans.
below and write a few lines about their causes, Causes :
consequences and helpful measures.
Ans. (i) Water logging due to heavy rains, broken down,
(1) Drought overflowing rivers, blockage of drainage basins etc.
Consequences:
(i) Widespread damage to crops, livestock,
infrastructure etc.
(ii) Cultural, environmental and ecological damage.
Helpful measures:
(ii) Man holes should be kept open for drainage.
(iii) People should avoid use of plastic.
(iv) Rescuing people from the water logged areas.
(v) Providing with temporary shelter and essential
commodities people.
Ans.
(3) Forest Fire.
Causes : No rains for a long period of time
Consequences:
(i) No growth of vegetation.
(ii) Spread of disease like acute respiratory and
gastrointestinal illnesses as well as other
infectious diseases.
Helpful measures:
(i) Water supply to be planned by government
in order to avoid recurrence of drought like
conditions
(ii) Storage and sanitation facilities to be provided
Ans.
including dams, rain water harvesting or better
irrigation techniques. Causes:
(iii) Vaccination programme to be implemented. (i) Increase in atmospheric temperature, lightening,
human activities, etc.
(2) Flood
Consequences :
(i) Rapid burning of trees increases the temperature.
(ii) Loss of forest area.
(iii) Huge loss of flora and fauna
Helpful measures :
(i) Avoiding any flammable substances to be carried
or spilling near forest area.
(ii) Quick contact to emergency services.
Disaster Management 193

(4) Road Accidents (6) Rail / Accident :

Causes:
(i) Negligence of train drivers or from the control room.
Ans. (ii) Infrastructural causes like collapse of bridge etc.
Causes : (iii) Track defects, Train collision, signal errors etc.
(i) It is usually caused due to over speeding and Consequences:
inefficient driving. (i) Loss of lives and injuries to many people.
Consequences :
Helpful measures:
(i) Victim may be hurt severely with fractures and
(i) Rescue operations by government authorities is
wounds. Sometimes it may be fatal.
necessary and exact cause of the accident to be
(ii) Victims should given proper medical aid.
found out.
(iii) Police to be informed.
(ii) Immediate medical treatment to all by making
(5) Earthquake
rescue camps in the vicinity is required.
(iii) Local people should help in these times to help
the less injured.
Q.4. Answer the following in brief.
*(1) What are the objectives of disaster management?
Ans. Objectives of disaster managements are as
follows:
(i) To minimise the loss of life caused during the
disaster and to save people from those disaster.
(ii) To supply essential commodities to the affected
people to reduce the impact of disaster.
Ans.
Causes: (iii) To rehabilitate the affected people to get back to
their normal life.
(i) Tectonic movements is the Earth's crust.
(iv) To take precautionary measures to avoid the
Consequences:
future occurrence of the disaster.
(i) Destruction of many buildings, hospitals,
*(2) Why is the essential to get training of first aid?
schools, etc.
Ans.
(ii) Loss of money and property.
(i) The first-aid training is extremely necessary for
(iii) Injuries and death of plants, animals and humans.
every citizen.
Helpful measures :
(ii) Use of this knowledge is useful for offering help
(i) People should not panic, they should try to take
to the people around facing any disaster and
shelter under a table or bed.
injury.
(ii) They should stay away from windows, protect
(iii) The first-aid measures differ from person to
then heads with pillows.
person according to the type and intensity of
(iii) If they are outdoors they should find a clear place disaster.
away from building, wires, etc.
194 Master Key Science and Technology Part - 2 (Std. X)

(iv) Victims of disaster need to be offered some (vi) First aid training helps people to face disaster
primary help before actual medical treatment. with courage, maintain their moral and give
First aid is useful in such circumstances. psychological support, which can be provided to
(v) First aid training can help in saving life in actual them by the people trained in first aid.
disaster time.

*(3) Which different methods are used for transportation of patients? Why?
Ans.

Cradle method: Carrying piggy back:

Useful for children and Useful for carrying
under-weight victims patients who are
unconscious.

Human crutch method : If one of the legs is Pulling or lifting method : This is used for
injured, the victim should be supported with carrying an unconscious patient, through
minimum load on the other eg. a short distance.

Carrying on two-hand chair: Useful for those

Carrying on four-hand chair: This is useful when patients who cannot use their hands but can hold
support is needed for the part below the waist their body upright.
Stretcher : In an
emergency, if a
conventional stretcher
Methods used is not available, then
by the fire- a temporary stretcher
brigade can be made using
bamboos, blanket, etc.

*(4) Explain the role of district disaster control unit (ii) District control unit is established immediately
after occurrence of any disaster. either after the impact of disaster or getting
Ans. information about it.
(i) At the district level, the district collector is (iii) It reviews about various aspects of disaster, keeps
responsible for disaster management and
continuous contact with various agencies like army,
implementation of rehabilitation schemes.
Disaster Management 195

airforce, navy, telecommunication department, *(7) How can we offer first aid to victims of any
paramilitary forces etc. for getting help. disaster?
(iv) It is also responsible for co-ordinating with Ans. Life and Rescucitation - ABC
various voluntary organizations for their help in
(i) Airway : If the victim has difficulty breathing,
disaster management.
the head should be held in a backward sloping
(v) It tries to establish the normal condition and
position or the chin should be raised so that the
proper rehabilitation as early as possible.
respiratory passage remains open.
*(5) Give the reasons for increase in human disasters
after the World War - II. (ii) Breathing : If breathing has stopped, the victim
Ans. should be given artificial ventilation by mouth to
(i) Planet Earth has experienced many natural mouth rescucitation.
disasters. (iii) Circulation : If the victim is unconscious, then
(ii) Most of the disasters are unpredictable situations after giving mouth to mouth respiration twice, the
that have occurred in the Asian continent and the heart should by pressed down hard by pressing
regions of Pacific ocean. the chest with both the palms. These two actions
(iii) In reality, previous problems of several years should be repeated alternately about 15 times. This
have been fierce. is called cardio-pulmonary rescucitation (CPR). It
(iv) Due to population explosion, the basic needs is helps to bring the circulation back to normal.
increased after the World War -II. *(8) Explain the nature and scope of disaster of flood
(v) Condition of instability arises in the country due with the help of points given beside. (Lets think;
to various reasons like economic inequality, racial Textbook Page no. 112)
and religious differences etc.
Ans. Taking into consideration the scope of disaster,
(vi) Incidences like terrorism, abduction, social
following are some of the important facts which
differences have been a routine now.
must be thought once as follows:
(vii) Nuclear testing is being done by many countries
(i) Pre-disaster phase- People are made aware
and use of Nuclear energy has increased resulting
through various media about the weather report.
in climatic changes.
Radio, television, internet can be used for sending
*(6) Whether there had been mock drill by fire
information.
fighters under the disaster management scheme
in your school? Which techniques did you see (ii) Warning phase- Fishermen, water transport
during the drill? authority and people near the bank of river are
(Can you tell; Textbook Page no. 118) warned not to get into water.
Ans. We observe very interesting and informative (iii) Emergency phase- People should be immediately
things during the drills at our school. We learnt rescued and taken to the safer places. People who
the following things from the fire fighters. are trapped in flood water should be rescued on
(i) How to rescue ourselves and others if there is any war level.
emergency in the classroom. (iv) Rehabilitation phase- Rescued and migrated
(ii) Switch off the mains if there is fire. people should be given the basic facilities
(iii) As we get any signal from smoke detectors, we required for life.
must run out of closed places. Transit camp should be built up and established
(iv) Classroom should have sand bags. which can provide necessary basic needs.
(v) If there is fire, contact fire brigade immediately. (v) Recovery phase- Try to recover the situation.
(vi) We came to know about what action should be Search for those who are missing.
taken if clothes catch fire. (vi) Reconstruction phase- Roads, water supply,
(vii) We also came to know, how to rescue people or agricultural practices should be brought back to
students stuck up at some height. normal.
vvv
196 Master Key Science and Technology Part - 2 (Std. X)

ASSIGNMENT - 10
Time : 1 hour Marks : 20

Q.1.(A) Answer the following: (3)

(1) Fill in the blank:
Earthquake is .................. type of disaster.
(2) Find the odd one out : Volcano, earthquake, land-slides, cyclones.
(3) Complete the analogy : Tsunami : Geological : : Hail storm : ..................
Q.1(B) Choose and write the correct options: (2)
(1) The Chairman of District disaster management is .................. .
(a) Prime Minister (b) Collector (c) Sarpanch (d) Chief Minister
(2) National Disaster Response Force has been established as per the Disaster Management Act
. (a) 2005 (b) 2015 (c) 1995 (d) 2007
Q.2. Answer the following (Any 2) (4)
(1) Distinguish between : Pre-disaster management and Post-disaster management.
(2) Complete the concept map.
Properties of
pre disaster management

Identifying the
pro disaster areas

Getting special training

for disaster management
(3) Write short note on Importance of Mock Drill.
Q.3. Answer the following (Any 2) (6)
(1) Identify the picture and state its effects.

(2) What is forest fire? What is its effects on environment?
(3) What are the objectives of disaster management?
Q.4. Answer in detail (Any 1) (5)
(1) Explain the main aspects of disaster management cycle.
(2) Explain the structure of Disaster Management Authority.

vvv
Model Activity Sheet 197

MODEL ACTIVITY SHEET

Time : 2 hrs Marks : 40

Q.1 (A) Solve the following questions (5)

(1) Complete the following table
Local name of plant Name of active Uses
ingredient
(a) ______________ Vasicine present in _____________
the leaves
(2) Which of the following is different from the others? Why ?
Solar electricity, wind electricity, atomic electricity, hydro electricity
(3) Is the given statement true or false? Why?
But a single person, if determined, can established a new forest.
(4) Give full form of NADH2.
(5) Complete the table.
(Motor accident, land sliding, forest fire, theft, riot, war, epidermic, drought,
locust attack, financial crisis, food famine)
Disaster Symptoms Effect Remedy

Q.1 (B) Choose the correct alternative and rewrite the statement. (5)
(1) Role of glutamic acid obtained by microbial processing is
(a) To impart acidity (b) Protein binding
(c) Essence (d) Artificial sweetner
(2) Which special cells are present in the body of sponges (Porifera)?
(a) Collar cells (b) Cnidoblasts
(c) Germ cells (d) Ectodermal cells
(3) In a flower, the male whorl is ..........................
(a) corrolla (b) calyx
(c) androecium (d) gynecium
(4) Which of the following factors are distributing the social health?
(a) mental stress (b) addiction
(c) incurable disease (d) all of the above
(5) Nuclear membrane disappears completely in the phase called ............... of Karyokinesis.
(a) prophase (b) metaphase
(c) anaphase (d) meta and anaphase
198 Master Key Science and Technology - 2 (Std. X)

Q. 2. Solve the following questions (any 5) (10)

(1) Observe the following figure and explain.

(2) Give your opinion about whether hydroelectric plants are environment friendly or not?
(3) Identify the animal in the following diagram. How can this be an evidence regarding
evolution?

(4) Which factors affect the social health?
(5) Complete the following chart.
Body cavity Germ layer Phylum
Absent __________ Porifera
Absent Triploblastic __________
Pseudocoleom ___________ Aschelminthes
Present ____________ Arthropoda
(6) Why is it asked to segregate wet and dry waste in each home?
(7) (i) What does the process in the following flowchart indicate?
(ii) What type of problems are faced?

Chemical energy Thermal Kinetic energy in Kinetic energy in Electrical
in coal energy steam turbine energy

Q. 3. Solve the following questions (any 5) (15)
(1) Answer the question with reference to the following figures.

(a) What is probiotic food famous for?
(b) Why have the probiotic food have developed much importance in recent days?
Model Activity Sheet 199

(2) Observe the following figures and answer the question

(a) Which process are shown in the figures above? Explain both the process.
(b) Why some characters are transmitted from parents to their offsprings.
(3) Explain with suitable diagrams the process of mitosis in detail.
(4) Identify the following chemical reaction and answer the questions.

(a) What is this chemical reaction related to?
(b) What is brought about in this reaction?
(5) (a) Complete the following chart.
(b) Why is conservation of environment the need of hour?
(c) Which role will you carry out as a student?

Need of
To maintain the To solve the natural and
Environmental artificial problems
balance in nature
conservationn

200 Master Key Science and Technology - 2 (Std. X)

(6) Observe the following figure and answer the following questions.

(a) Which energy is produced?

(b) What is this Power Plant based on?
(c) Is this energy generation eco-friendly? Why?
(7) Observe the following pictures of animals, classify them and write their classification.

(a) Wall Lizard (b) Pigeon

Q. 4. Solve the following question (Any 1) (5)

(1) Observe the figure and answer the following.
(a) What is the figure related to?
(b) What is the process of production of fuel?
(c) Why is the process shown in figure important?
(d) Which fuels are obtained from this process?
(e) Write a paragraph on ‘Saving fuel is need of the hour’.
(2)

(a) Observe the above images. Is it rational? Why?

What solution will you give for the above mentioned issues?
(b) Make two categories as time spent on your health and time spent on other
responsibilities and compare both the categories.
vvv