Springfields School

Tolichowki
Biology Class 10 Chapter 1: Nutrition Notes
Objectives:
Nutrition - Types
Autotrophic nutrition - Photosynthesis
Theories of Scientists
Heterotrophic nutrition - Types
Digestion in human beings
Malnutrition and its diseases
Vitamins and their sources
Question and Answers

Important points:
Nutrition: The procurement of food by living organisms is
called nutrition. It is mainly of two
types.
i)Autotrophic nutrition and
ii)Heterotrophic nutrition
i)Autotrophic nutrition: The process
of preparation of food by the organism
itself. Example: Plants
ii)Heterotrophic nutrition: The
dependence of the organism on some
other organisms for food. Example:
Amoeba, worms, fungi and humans
etc.
Types of heterotrophic nutrition:
i)Holozoic nutrition: Taking solid food.
Example: Amoeba, humans
ii)Parasitic nutrition: One organism living in or on the body of the other organism for food.
Ectoparasite: Example: louse, leech Endoparasite: Example: virus, tapeworm, roundworm etc.
iii)Saprophytic nutrition: Dependence of organisms on dead and decaying matter for food.
Example: fungi, bacteria
iv)Symbiotic Nutrition: Interdependence of two organisms for food and shelter. Example:
Lichens (Algae, Fungi); (Rhizobium bacteria, Leguminous plant)
Autotrophic Nutrition: Photosynthesis: The process by which plants containing green pigment,
chlorophyll build up complex organic molecules from relatively simple inorganic ones using
sunlight as energy source.
Equation 1: CO2 + H2O-------light & chlorophyll---------> CH2O + O2 + H2O (C.B. Van
Neil)
Equation 2: 6CO2 + 12H2O ------light & chlorophyll-------> C6H12O6 + 6O2 + 6H2O
(Robert Hill)
Theories of Scientists:
Van Neil: He experimented on purple Sulphur bacteria using H2S and observed that sulphur is
released.When H2O is used O2 is released.
Von Helmont: He proposed that mass growth of the plant is due to water.
Joseph Priestley: He discovered oxygen. He stated that plants restore the air that breathing
organisms and burning candles remove.
Lavoisier: He coined the name oxygen to the gas.
Jan Ingenhousz: He proposed that oxygen is released only in the presence of light during
photosynthesis. He also proposed that only green plants part carry out photosynthesis.
Pelletier and Caventou: They obtained an extract of green pigment from plants and named it
as chlorophyll.
Julius Von Sachs: He proposed that chlorophyll is present in small structures called
chloroplasts in the plant cell.
Daniel I Arnon: He broke up the plant cell to obtain chloroplast.
T.S of Leaf. T. S of Chloroplast

Each plant cell contains 40 - 100 chloroplasts.

Chloroplast: It is a double membraned structure with stacked structures called thylakoids. Each
stack is called granum. The fluid filled portion for enzymatic reactions which leads to synthesis
of glucose is called stroma. Chlorophyll pigment present in thylakoids has one atom of
magnesium. Chlorophyll a is Blue green and chlorophyll b is yellow green. These are called
photosynthetic pigments.
Events in photosynthesis:
Light reaction (light dependent reaction of photochemical phase)
i) Absorption of light by chlorophyll: Chlorophyll gets activated on exposure to light and
absorbs photons.
ii) Photolysis of water: The energy absorbed is used in splitting of water molecules(H2O) into
H+ and OH- ions. OH- ions after a series of reactions form water and oxygen. H+ ions combine
with NADP and form NADPH2.
4OH- -------> 2H20 + O2
NADP + 2H+ ------> NADPH2
iii) Photophosphorylation: Adenosine diphosphate combines with inorganic Phosphate and
forms and Adenosine triphosphate.
At the end of the light reaction ATP and NADPH2 are formed. These are called assimilatory
powers.Light reaction occurs in the grana of chloroplast.Light reaction is also called Hill reaction
as it was discovered by Robert Hill.
Dark reaction (light independent reaction or biosynthetic phase)
During dark reaction NADPH2 splits and H2 is released.Carbon dioxide undergoes reduction
when it combines with H2 and forms glucose (C6H12O6) which later forms starch (C6H10O5)n.
Dark reaction occurs in stroma of chloroplast. It
was discovered by Blackman and Melvin
Calvin.

Experiment 1: Mohl's half leaf experiment:

Aim: To prove that Carbon dioxide is necessary for photosynthesis.
Apparatus: Potted plant, Potassium Hydroxide ( KOH) solution, test tube, clip, split cork,
Methylated spirit, gas burner, beaker, Iodine, glass plate, water.
Precautions: Destarch the plant by keeping it in dark for a week.See that the leaf in the bottle
should not touch KOH solution. Keep the plant well exposed to sunlight after taking it out from
dark.
Procedure: Take a wide mouthed transparent bottle. Put KOH pellets or solution in the bottle
that absorbs Carbon dioxide. Insert a leaf of the destarched plant in the bottle through a split
cork such that half of it is inside the bottle. Leave the plant in sunlight for a few hours before it is
tested with iodine. Pluck the leaf and boil it in 1% methylated spirit to remove chlorophyll.Test
the leaf with iodine.
Observation: It is observed that the part of the leaf outside the bottle turns blue black when
tested with iodine and the part inside the bottle remains the same.
Inference: Photosynthesis takes place in the leaf in presence of carbon dioxide outside the
bottle and it does not take place in part of the leaf inside the bottle as Carbon dioxide is
absorbed by Potassium Hydroxide.
Result: Hence it is proved that Carbon dioxide is
necessary for photosynthesis.
Experiment 2:
Aim: To prove that sunlight is necessary for photosynthesis.
Apparatus: Potted plant, black paper, clip, iodine solution, methylated spirit, test tube petri dish.
Precautions: Fix the black screen firmly on the leaf. The plant should be well exposed to
sunlight during the experiment.
Procedure: Take a potted plant and destarch it. Cover a part of one of the leaves with black
paper. Place the plant in sunlight for a few hours. Pluck the leaf and test it with iodine for the
presence of starch after boiling it in the Methylated spirit.
Observation: We observe that the part of the leaf covered with black paper does not turn blue
black whereas the part of the leaf exposed to sunlight turns blue black.
Inference and generalisation: We can infer that sunlight is necessary for photosynthesis.

Experiment 3:
Aim: To prove that oxygen is produced during photosynthesis.
Apparatus: Two identical sets of test tubes, beakers, water, hydrilla plant, glass funnel and a
burning splinter.
Precautions: Handle the apparatus carefully. Fix the hydrilla plant firmly in the funnel.
Procedure: Place some twigs of hydrilla plant in a short stemmed glass funnel. Keep the funnel
in a beaker full of water in an inverted position. Invert a test tube with water over the stem of the
funnel. Place one such setup in the dark and the other in sunlight for 2 to 3 hours.
Observation: We will observe that the setup placed in sunlight shows gas bubbles in the test
tube but in the other setup we find only a little gas. When this gas is tested with a burning
splinter it burns brightly confirming the presence of oxygen.
Inference: Hence it is proved that oxygen is produced during photosynthesis.

Heterotrophic Nutrition:
i)Holozoic Nutrition: Amoeba acquires
its food by extending its body surface
towards the food particle with the help of
pseudopodia. It engulfs the food through
its body surface and forms a food
vacuole.
In Paramecium food is moved towards a
specific spot called cytostome and is
ingested and then it is circulated in the
body in the form of a food vacuole.
ii) Parasitic Nutrition: A parasitic plant called cuscuta grows on any host plant. It develops
root-like structures called haustoria to extract nutrients and water from the host plant. It has
scales like leaves and flowers in the form of clusters like nodules. When the seed germinates it
gives rise to an anchoring root and a spiral stem. It resembles a fine densely tangled web
enveloping the host plant. The anchoring root rots later. It is also called a dodder plant.
Human Digestive System: The digestive tract starting from mouth to anus is called alimentary
canal or gut.
 Cuscuta on Plant

Digestion in mouth:
Ingestion: Taking food in the mouth is called
ingestion.
Mastication: Crushing, biting, cutting and grinding of food and mixing with saliva is called
mastication.
Digestion: The process of breaking down complex substances into simple substances with the
help of enzymes is called digestion.
Salivary glands: There are three pairs of salivary glands in the mouth, two pairs are at the side
of the lower jaw and one in the palate. They produce saliva which contains salivary
amylase(ptyalin). It acts upon starch and converts it into maltose.
Starch(Complex sugar)+Salivary Amylase----->Maltose(Simple sugar)
Tongue: It helps in mixing the food with saliva and pushing the food in oesophagus with the
help of the lower jaw.

Oesophagus: Food, which is now called bolus, enters oesophagus from which it goes into the
stomach with the help of peristaltic movements and slimy mucus.

Digestion in Stomach:
Hydrochloric acid and gastric juice are produced in the stomach when the food enters in it.
Hydrochloric acid kills germs and converts food in very small particles as it churns the food is
now called chyme. Pepsin enzymes act on proteins and form peptones.
Proteins(complex) + pepsin ----> Peptones(simple)
Digestion of carbohydrates does not take place in the stomach as it is highly acidic. It resumes
in the small intestine as the medium becomes alkaline.
Digestion in Small Intestine:
Liver: it secretes bile juice that acts upon fat and converts it into small globules.
Fat + bile ----> small globules
Pancreas: It produces pancreatic juice which contains trypsin, amylase and lipase enzymes.
i) Proteins + trypsin ----> Peptones
ii) Carbohydrates + amylase ----> Maltose
iii) Fats + lipase ------> Fatty àcids and glycerol
Small Intestine:
Walls of small
intestine produce
intestinal juice
(succus entericus)
which contains
peptidase and
sucrase enzymes.
Peptides +
peptidase ----->
Amino acid
Sucrose + sucrase
-------> Glucose
At the end of
digestion, the final
products glucose,
amino acids and
fatty acids are
absorbed by
finger-like
projections called
villi in the small intestine and pass to blood vessels and lymph vessels.
Large Intestine: The undigested food passes to the large intestine where maximum absorption
of water takes place.
Defecation: The passage of undigested food material from the body by the way of anus is
called defecation.
Problems Digestion: Reasons: Not taking food on time, less sleep and overeating. Vomiting is
caused when a heavy diet or poisonous food goes in the stomach. Green vomiting (bilious or
liverish) occurs when a heavy diet is taken continuously for a long period.
Steps to avoid problems: Taking a simple and balanced diet, eating in a leisurely manner,
thoroughly masticating the food, avoiding violent exercises soon after taking food, and drinking
a lot of water.
Ulcers: Ulcers are caused in the stomach and small intestine due to hurry and worry. Peptic
ulcers are caused by a bacterium called Helicobacter pylori.
Proper functioning of all the systems needs a proper amount of food.
Intake of a proper amount of water and fiber rich food can avoid constipation.

Balanced diet: Food having all the nutrients required by a body in proper proportion is called a
balanced diet.
Malnutrition: Eating food that does not have one or more
than one nutrient in proper proportion is called malnutrition.
Reasons or factors of malnutrition: Poor health, lack of
awareness, willful starvation and socio-economic factors.
Types of malnutrition:
Calorie malnutrition (Obesity) Protein malnutrition
(Kwashiorkor) Protein calorie malnutrition (Marasmus)
Obesity: This is caused due to overeating and excess of
energy intake where 20% of body weight is due to fats.
Obese people suffer from cardiovascular renal and
gallbladder problems and also diabetes.
Protein malnutrition (kwashiorkor): It means a displaced
child. The child is weaned out. The child has a moon shaped
fluffy face. He or she has swollen body parts due to
accumulation of water in intercellular spaces. Dry and loose skin and poor muscles. Loss of
appetite and slow growth. Diarrhea and dull hair.
Protein calorie malnutrition (marasmus): The child's body shows reduced growth. The child
looks smaller than his age.He or she is highly irritable and has voracious hunger.The child has
dry skin, dull hair and diarrhea. He or she has less developed muscles.
Vitamins: They are organic substances required by our body in small amounts. The sources of
vitamins are food, sunlight and bacteria in our intestine. Vitamins are of two types. Water soluble
and fat soluble vitamins. Water soluble vitamins: Vitamin B1, B2, B3, B5, B6, B7, B9, B12 and
Vitamin C.Fat soluble vitamins: Vitamin A, D, E and K

Important Question & Answers:

1. Why do we use KOH in Mohl's half leaf experiment?
A. In Mohl's half leaf experiment KOH solution is used to absorb Carbon dioxide present in glass
bottles.

2. Which digestive juice doesn't contain enzymes?

A. Bile juice secreted by the liver does not contain digestive enzymes.

3. Why is it necessary to destarch a plant before performing an experiment on photosynthesis?

A. When we perform an iodine test, if starch is present, it turns blue. If there is any starch left out
in the leaves, it may interfere with the result of the experiment and may give false positive
results.

4. What is the role of saliva in the digestion of food? or What if salivary glands are closed?
A. Saliva helps in smooth passage of food through the alimentary canal. It contains an enzyme
amylase (ptyalin) which helps in the breakdown of complex carbohydrates into simple ones.

5. How do you remove chlorophyll from the leaf before conducting an iodine test?
A. Take a leaf from a potted plant. Boil the leaf in methylated Spirit or ethanol over a water bath.
It becomes pale white due to removal of chlorophyll.

6.Do you think the new reddish leaves of the plant also carry out photosynthesis?What would be
the role of the colour?
A.It was found that pigments other than green could also aid in photosynthesis by passing on
the energy of sunlight trapped by them to chlorophyll.

7. Distinguish between a) light and dark reaction b) autotrophic and heterotrophic

nutrition,/plants and animal nutrition c) ingestion and digestion d) haemoglobin and chlorophyll
e) kwashiorkor and marasmus
A.a) Light and dark reaction:
Light reaction:1. Light is essential for this reaction. It occurs in the grana thylakoids of
chloroplast. Water molecules split into H2 and O2 using sunlight. ATP and NADPH2 are
formed.CO2 is not needed. It was discovered by Robert Hill.
Dark reaction: 1. Light is not needed for this reaction. It occurs in the stroma of the chloroplast.
From carbon dioxide and water carbohydrates are formed. ATP and NADPH2 are utilised.CO2
is utilised. It was discovered by Blackman and Melvin Calvin.
b) Autotrophic and heterotrophic nutrition:
Autotrophic nutrition:1. Organism prepares its own food. It is independent for its food
requirements. Example: green plants
Heterotrophic nutrition: Organism does not prepare its own food. It depends on plants and
other organisms for food requirements. Example: animals, human beings etc.

c) Ingestion and digestion:

Ingestion:1. Ingestion is taking of food into the body. Food is taken through only mouth
.Enzymes are not needed. It takes only a few minutes for ingestion.
Digestion: 1. Digestion is breaking up complex food substances into simple substances .Entire
digestive system is involved. Enzymes are needed. It takes some hours for digestion.

d) Hemoglobin and chlorophyll:

Chlorophyll:1. It gives green colour to the leaf.2.It has magnesium molecules
Hemoglobin:1. It gives red colour to blood. It has an iron molecule.

e) kwashiorkor and marasmus:

Kwashiorkor: 1. It is the deficiency of proteins. The child has a moon shaped fluffy face,
swollen body parts due to accumulation of water in the intercellular spaces. The child doesn't
feel hunger. Very poor muscle development. Diarrhea and dry skin.
Marasmus: 1. It is the deficiency of both proteins and calories. The child looks smaller than his
age with lean and weak limbs. The child has voracious hunger. Less developed muscles.
Diarrhea and dry skin.

Fill in the blanks:

1. Delay in healing wounds and fracture of bones are due to _____.(Vitamin C/ Vitamin A)
2.Root like structures in cuscuta that penetrate the tissue of a host plant to absorb food is
(proboscis/haustoria)
3. Name the disease that is caused due to deficiency of Vitamin D _________. (Scurvy/Rickets)
4. Glossitis disease is caused due to the deficiency of ___________. ( Vitamin B2/Vitamin B6)
5.Deficiency of Folic acid, Vitamin B9 causes ___________ (Burning feet/Anaemia)
6.Deficiency of both protein and calories in children causes _________. (Kwashiorkor/
Marasmus)
7.The acid present in gastric juice is _____ (HCl/HNO3)
8. Fats are emulsified by ________ (bile juice/pancreatic juice)
9. Fat soluble vitamins are _________ (Vitamin B. Complex/Vitamin A,D,E,K)
10.Chemical formula of glucose is _________ (C6 H10 O5)n / C6H12O6)
11._________ discovered the importance of light in photosynthesis. (Van Neil / Ingenhousz)
12. Oxygen was discovered by ______ (Priestley / Lavoisier)
13.Light reaction takes place in _______. (Grana / stroma)
14._________ is called sunshine vitamin.(vitamin D / vitamin E)
15. Complete digestion of carbohydrates, proteins and fats occur in ________ (Small Intestine /
Large Intestine)
Chapter 2: Respiration (Running notes)
Objectives:
Respiration
Events in respiration
Components of air
Pathway of air
Breathing and Swallowing
Structure and capacity of lungs
Mechanism of respiration
Aerobic and Anaerobic respiration
Structure of Mitochondria
Graph on lactic acid formation
Activities on combustion, aerobic and anaerobic respiration
Respiration in plants
Questions and Answers

Definition: Respiration: The process of breaking down food for release of energy.

The word 'respiration' is

derived from the Latin
word 'respire' which means
breathe. The term
respiration was used in
the 14th century for the first time.
Lavoisier and Priestley did a comprehensive study on properties of gases. They named the
gases like:
Vitiated air: Air without Oxygen. Chalky acid gas or fixed air: Carbon dioxide.
Respirable air or gas needed for burning: Oxygen.
They concluded that respirable air is changed into fixed air.

Events in respiration:
Breathing Gaseous Gas transport by Gaseous Cellular respiration
exchange at blood exchange at
lung level tissue level
Air movement Exchange of Transport of oxygen Exchange of Using oxygen in
into and out of gases between from blood capillaries oxygen from cell processes to
lungs alveoli and of alveoli to body cells blood into cells burn glucose to
blood and return of Carbon and carbon produce carbon
dioxide dioxide from dioxide and water
cells into blood releasing energy to
be used for life
processes.
Components of Air
Gases Inhaled air Exhaled air
Oxygen 21% 16.4%
Carbon dioxide 0.04% 4.4%
Nitrogen 78% 78%
Water vapour A little A lot
Pathway of Air:
Nostrils Nasal Pharynx Larynx Trachea Bronchus Bronchioles Alveoli Blood
cavity
Air Air is It is a It It directs Windpipe From each Bronc It
enters filtered passage contain air into divides bronchus hioles carrie
through by tiny of air & s vocal lungs. into two many termin s O2
nostrils hairs. It food - cords bronchi branches ate in to all
become air is that leading called cluster cells
s moist made vibrate into each bronchioles s of air &
& warm. warm & on lung. arise. sacs collec
moist exhalati for ts
on of gaseo CO2.
air. us
excha
nge.

Breathing and Swallowing: From the nasal

cavity the air goes into the pharynx. From there two passages arise with nearly the same
opening and ending in separate canals
for air and food. From there air enters the windpipe.
Epiglottis protects the tubes to lungs, arresting the entry of food into lungs. Epiglottis partly
closes when we swallow food. It deflects food down to the stomach.
Structure and capacity of lungs: Lungs are spongy. Left lung is smaller than the right one as
it has to provide space for our heart.Lungs are covered by two membranes called pleura,
between which there is a liquid which protects the lung from injury. There are millions of alveoli
in our lungs,much folded and covering a vast area of 160 m square.
When we exercise or run we breathe faster and deeper for greater supply of Oxygen and
removal of CO2. Total capacity of lungs is 5800 ml of air but 500 ml of air is passed while
breathing. When we breathe out 120 ml of remains in the lungs.
Transport of gases via blood in the body depends upon the amount of gases in air and their
combining capacity. If oxygen is present within its normal limit (21%) then all of it combines with
haemoglobin to form oxyhaemoglobin. Oxygen is transported through blood in the form of
bicarbonates. Some amount is dissolved in blood plasma.

While breathing in haemoglobin combines with Oxygen and forms Oxyhaemoglobin

Hb + O2 —----> HbO2
While releasing Oxygen during cellular respiration, it breaks down
HbO2 —-----> Hb + O2

Mechanism of Respiration:

Structure of Mitochondrion Graph on lactic acid concentration in blood of an athlete

This graph shows great variation when lactic acid

concentration in muscles of an athlete accumulates resulting in muscular pain when sugar is
changed to lactic acid in working muscles. The energy stored in lactic acid could be used to
rebuild ATP from ADP and phosphate.
During a 100 m race an athlete holds his breath then afterward he pants. His muscles are using
energy released during anaerobic respiration. Afterwards the athlete obtains oxygen to remove
lactic acid. Therefore when we undertake strenuous exercise we buildup an oxygen debt which
has to be repaid later.
Aerobic respiration: Respiration in the presence of oxygen. It takes place in cytoplasm and
mitochondria Plant and Animal cells.
Anaerobic respiration: Respiration in absence of oxygen. It takes place in cytoplasm of
bacteria and yeast cells.
The energy produced in mitochondria is stored in the form of ATP in the cells. So mitochondria
is called the powerhouse of the cell. ATP is called energy currency.Each molecule of ATP gives
7200 Calories of energy which is stored in the form of phosphate bonds.
Fermentation: When yeast cells are introduced in glucose solution they act upon it converting
it into ethyl alcohol. When ethyl alcohol is formed, it is removed by fractional distillation.
Fractional distillation: Separation of liquids from a mixture depending upon their boiling points.
The boiling point of Ethanol is 70 C.
Evolution in gaseous exchange system:
Parazoa,Porifera & Coelenterata: Organisms obtain O2 and expel CO2 by diffusion through
the body surface. Ex: Amoeba, Sponges and Hydra
Arthropoda: Respiration takes place through a tracheal system consisting of tubes called
trachea which divide into branches called tracheoles that carry air to cells in tissues.
Pisces: They respire through gills or branchiae keeping their mouth open and lowering their oral
cavity. As water enters inside they raise their oral cavity pushing water through gills. Gaseous
exchange takes place with blood capillaries in gills.
Amphibians: Cutaneous respiration takes place in amphibians. They also respire with lungs.
Ex: Frog
Aves, Reptiles & Mammals: They respire through lungs. Ex: Pigeon, snake, tiger, goat etc

Respiration in plants: In roots, stem and leaves respiration takes place through root hairs,
lenticels and stomata.

Mangroves respire through aerial roots or pneumatophores.

In orchids there is a tissue that produces oxygen.
Anaerobic Respiration Aerobic Respiration

Combustion of Sugar: Sugar is burnt

releasing carbon dioxide
Exhaled air activity: When air is blown
in lime water , it turns milky white.
Ca(OH)2+CO2—-->CaCO3+H2O
Questions and Answers:
1. In what compound the energy released during the breakdown of glucose is stored?
A. The energy released during the breakdown of glucose is stored in ATP in the form of
chemical bonds.
2. What happens if there is no epiglottis in humans?
A. Epiglottis is a flap-like valve which protects the windpipe from the entry of food. It partly
closes when we swallow food and opens more widely when we take breath. If epiglottis is
absent both air and food pass through pharynx at a time and may cause choking.

3. Fermented Idli and dosa produce a smell. Name the organism responsible for it.
A. Yeast, which is a fungus, causes fermentation. During fermentation sugars are converted into
ethyl alcohol. So we get the smell from fermented products like dosa and idli etc.

4. Where will the release of energy from glucose in respiration take place? Lungs or muscles.
Why?A. This takes place in the muscles. Glucose splits down to release energy during
respiration. Energy is made available to the parts of our body through the bloodstream. In lungs
only gaseous exchange takes place.

5. What happens if diaphragm is not there in the body?

A. If the chest cavity is imagined as a room then diaphragm may be imagined as its floor.
Without diaphragm the lungs are unable to perform any function. Diaphragm is a flexible and flat
muscle that helps in moving air into and out of lungs. Also the internal organs may move up and
cramp the lungs itself making breathing difficult if diaphragm is not present.

6. How do green plants respire in absence of Sunlight?

A. Plants utilize oxygen that is released during photosynthesis. In absence of Sunlight there will
be no photosynthesis and no supply of oxygen to the cells for respiration.

7. After vigorous exercise or work we feel pain in muscles. What is the relationship between
pain and respiration?
A. When we do vigorous exercise our muscles are unable to meet the oxygen demand. Hence
muscle cells respire anaerobically as our body requires instant energy at that stage. Due to
anaerobic respiration (breakdown of glucose),formation of lactic acid takes place which results
in pain in the muscles.

8. What are the areas on the plant body through which gaseous exchange takes place?
A. The areas on the plant body through which gaseous exchange takes place are stomata on
leaves, lenticels on stem and surface of roots.

9. Where does water vapour come from in exhaled air?

A. During respiration Carbon dioxide and water are formed with release of energy. So, exhaled
air carries water vapour.
10. What happens when a baker prepares dough by mixing yeast in it?
A. The dough rises and increases in size as yeast cells carry out anaerobic respiration releasing
Carbon dioxide.

11. Why do mountaineers carry oxygen cylinders with them when they climb higher altitudes?
A At higher altitudes oxygen is about ⅕ part as compared to sea level. Blood cannot carry
oxygen to tissues at higher altitude. So mountaineers carry oxygen cylinders with them.

12. What is the role of diaphragm and ribs in respiration? Are both active in man and woman?
A. Lungs themselves can neither inhale or exhale air. The chest wall is made up of ribs, muscles
and the skin. Ribs are attached at an angle to the spine. Diaphragm may be imagined as the
floor and the chest cavity as a room. During inhalation the diaphragm contracts, it flattens out a
bit and the dome moves downwards. As a result the volume of the chest cavity is increased with
this internal pressure decreases and the air from outside rushes into the lungs.
Then the reverse occurs. During exhalation the chest wall is lowered and moves inward and the
diaphragm relaxes and assumes a dome shape. These changes increase the pressure on the
lungs, their elastic tissue contracts and squeeze the air out through the nose to the external
atmosphere.
Ribs protect the lungs and expand as we inhale to facilitate space for the lungs to expand. The
ribs then contract expelling the air in the lungs. The intercostal muscles present between the
ribs help in contraction and relaxation of ribs.
In men diaphragm plays a major role in respiration while in women the ribs play a major role.

13. Distinguish between photosynthesis and respiration.

A. Photosynthesis: 1.It is an anabolic process. It occurs in plants and some photosynthetic
bacteria. It takes place in the presence of Sunlight. In this process light energy is fixed or
utilized. Oxygen is liberated. It takes place in the chloroplast.
Respiration: 1. It is a catabolic process. It occurs in all living organisms. It takes place
throughout the day and night. In this process energy, Carbon dioxide is released. It takes place
in the mitochondrion.

14. Explain an activity to prove that heat and carbon dioxide are evolved during aerobic
respiration.
A. Heat is evolved during respiration: Procedure: 1. Take some germinating seeds in a thermos
flask. Insert a thermometer through the flask by a one holed rubber cork. Close the flask and
record the temperature for every 2 hours.
Observation and result: It is observed that the temperature rises which shows that heat evolved
during respiration.
Carbon dioxide is released during respiration: Procedure:1. Take a wide mouthed bottle with
germinating seeds in it. Take lime water in a beaker and place it in the wide mouthed bottle such
that no air enters the flask. Keep the setup undisturbed for 2 to 3 hours.
Observation and result:It is observed that limewater turns milky. This shows that the germinating
seeds respire producing carbon dioxide which turns the lime water milky.
15.Explain an activity to prove that heat and carbon dioxide are evolved during anaerobic
respiration.
A. Take a boiling tube with glucose in it. Warm it and keep it undisturbed. After sometime, test it
with Janus Green B solution to check the presence of Oxygen. If the solution turns pink Oxygen
is present. Now throw the solution and take a fresh one. If it doesn't turn pink now add yeast
cells in glucose.Put a layer of paraffin wax in the tube. Insert a thermometer and a double bent
tube in the boiling tube. The other end should be put in a test tube with lime water. Keep the
setup undisturbed for 2 to 3 hours.
Observation and result: It is observed that limewater turns milky and temperature readings show
high in the thermometer. This shows that the yeast cells respire anaerobically producing carbon
dioxide and heat.
Fill in the blanks
1.Vocal cords are present in _______. (larynx /pharynx)
2. Clusters of air sacs in lungs are called ______. (alveoli/bronchi)
3. Aerial root respiration is seen in _________ (mangoes /mangroves)
4. Components present in ________ air are Carbon dioxide and water vapour. (Inhaled
air/exhaled air)
5. Respiration is a _________ process because of breakdown of complex food molecules. (
anabolic /catabolic)
6. Energy currency of the cell is ________. ( ATP / Mitochondria)
7.Diaphragm attains a dome shape and contracts during ________. (inhalation / exhalation)
8. Haemoglobin has the binding capacity with _______. (Nitrogen / Oxygen)
9. Total lung capacity of human beings is _______ ( 5800ml /6000ml)
10. The most commonly used sugar for deriving energy in living organisms is ________.
(glucose /sucrose)
11. And products of fermentation are ______ & _______. (ethyl alcohol / carbon dioxide /
oxygen /lactic acid)
12. The factors that affect the ratio of photosynthesis and respiration in plants is ______,
________ & ________ (temperature /humidity /light intensity /none)
13.______ % of Carbon dioxide is present in exhaled air. (0.04 % / 4 %)
14. Accumulation of ________ in muscles results in muscular pain. (lactic acid / acetic acid)
15.In cockroaches air enters the body through ________ ( spiracles / gills) and type of
respiration is called ________ respiration. (bronchial / tracheal)
Chapter 3: Transportation (Running Notes).
Objectives:
Pulse rate per minute
Structure of heart
Major blood vessels
Theories of scientists about circulation
Cardiac cycle
Single and double circulation
Lymphatic system
Blood pressure
Coagulation of blood
Transport of substances in different organisms
Root pressure
Mind map: Solids \ / Growth
Liquids ------ Life Processes. ----- Maintenance
Gases / \ Energy
Substances are passed throughout the body of organisms with the help of a system.
In lower animals like amoeba or hydra etc. transport of substances takes place by diffusion or
osmosis.
In higher animals a system called circulatory system is used to transport substances throughout
the body as diffusion would take years to transport substances.

Heartbeat and pulse rate:They both have the same value.

Rene Laennec invented a stethoscope to count the heartbeats of people.
Pulse rate: It is the rhythmic beat of heart and blood vessels. It varies from person to person
and situation to situation.
I found my pulse rate to be ______per minute.
Pulse rate per minute in different people:
Newborns Infants Infants Children Children over Well trained
(0-3 months) (3-6 months) 6-12 months 1-10 yrs 10 years & athletes
senior
citizens
100 - 150 90 - 120 80 - 120 70 - 130 60 - 100 40 - 60

Structure of human heart (External):

A heart is a pear shaped structure approximately the size of your fist. It is located between the
lungs and protected by a rib cage. It is covered by two membranes called pericardium between
which there is a pericardial fluid which protects the heart from shocks. The blood vessels found
on the walls of the heart are called coronary vessels which provide blood to the muscles of the
heart.
 Structure of human heart (Internal):
The heart is divided into four chambers by grooves. Upper chambers are called auricles which are thin
walled and lower chambers are called ventricles which are thick walled. Left chambers are smaller than
right ones. Left and right auricles and ventricles are separated by two septa. The valve between the right
auricle and right ventricle is called tricuspid (right auriculo ventricular valve). The valve between the left
auricle and left ventricle is called bicuspid or mitral (left auriculo ventricular valve).

Passage of blood:
Body------------> Superior and Right auricle Tricuspid valve Right ventricle Pulmonary
inferior vena ---------> artery
^ cava-----------> ---------------> -------------->
V
!
! Aorta Left ventricle Bicuspid valve Left auricle Pulmonary Lungs
veins
<-------------- <-------------- <------------- <-------------
<------------

Major blood vessels:

.

Differences Between Arteries and Veins

Structure & Function Arteries Veins

Thickness of wall Thick Thin

Valves Absent Present

Capacity to retain shape in Can retain shape Cannot retain shape

absence of blood

Direction of Blood From heart to body From body to heart

Pressure in the vessels High Low

Type of Blood Transported Oxygenated Deoxygenated

Type of Blood in Pulmonary Deoxygenated Oxygenated

Vessels
Theories of scientists on blood vessels and circulation:
Girolamo Fabrici: In 1574 Fabrici studied the veins in legs.
He noticed that small valves are present in veins which
allowed the movement of blood in one direction. So valves
permit the blood to move up even when a person is standing
upright.
William Harvey: He dissected the hearts of dead people
and studied that the valves are one way. Valves allow flow of
blood from auricles into ventricles without any hindrance. So
he experimented on animals by tying blood vessels and they
bulged on the side away from the heart.
Harvey's experiment: If a tronquit is tied on an arm and the
fist of the same arm is closed tightly, the blood vessels can be seen prominently when the pressure is
applied on the farthest point of the elbow towards the palm.
Reduced flow of blood activity: When you sit with one leg dangling and the other resting on the first,
the one on the top will give a series of small movements with each heartbeat.After sometime you will
feel pins and needles in the leg due to reduced flow of blood.
Marcello Malpighi: He observed minute blood vessels (capillaries) in the wings of bats. He called them
capillaries which means hair in Latin.

Cardiac Cycle:

Cardiac cycle:The sequential events of

relaxation and contraction of auricles and
ventricles causing systole and diastole.

Single and Double Circulation:

.
Evolution in transport system:
Protozoa: It occurs by Brownian movement in which protoplasm movement occurs to distribute
nutrients and oxygen throughout the body. Example: Amoeba
Porifera: Water currents are created with flagella for transportation of substances in sea
Example: Sponges, Sycon etc.
Cnidaria: Water travels through blind sac like gastrovascular cavity which takes up the process
of digestion and transportation. Example: Hydra
Platyhelminthes: It has a highly branched digestive system that
transports food to all cells and collection of waste substances also
takes place from each cell. Example: Flatworm
Nemathelminthes: it has a pseudocoelom which takes up the
function of collection and distribution of substances. Example:
Roundworm
Annelids: It has a (pulsatile) beating vessel to move the fluids with
blood as medium. Example: Earthworm
Arthropods: White blood is directly passed by pulsatile organ (heart)
to tissues without blood vessels. So, it has an open circulatory
system. Example: Cockroach
Molluscs: Blue colour blood flows from heart directly to tissues. Open
circulatory system. Example: Unio, Pila
Echinoderms: It has a water vascular system which is a closed
circulatory system. Example: Starfish
All higher animals (vertebrates)and Octopus (molluscs) have closed
circulatory systems.

Lymphatic System: It consists of lymph, lymph vessels and lymph

nodes. It runs parallel to the venous system.It helps in transport of
substances and fights against infections.
Coagulation of blood: (agglutination or clotting) Bleeding from a
wound stops within 3 to 6 minutes in a normal person. This happens when platelets produce an
enzyme called thrombokinase. It acts on a substance in blood called prothrombin and converts
it into thrombin. Thrombin acts on fibrinogen in blood and converts it into insoluble fibres which
attach at the edges of the wound and pull them together. Blood cells entangle with fibrin to form
a clot.
Thrombokinase Thrombin
------------------------->
Prothrombin
Fibrinogen Thrombin Insoluble fibres
-------------------------->

Potted plant experiment( root pressure): Transpiration in Plants

Evidence that food is transported by phloem: Aphids extract food material from phloem
.

Questions and Answers:

1. What are the differences you find in the chambers of the heart? How are they connected to
each other? How are they separated?
A. Human heart consists of four chambers. The upper two chambers are called auricles. They
are thin walled. The lower two chambers are called ventricles. They are thick walled. The right
auricle opens into the right ventricle through the tricuspid valve. The left auricle opens into the
left ventricle through a bicuspid or mitral valve. Both auricles and both ventricles are separated
from each other by muscular partitions called septa.

2. How many blood vessels originate from the heart?

A. Two blood vessels originate from the heart. They are pulmonary artery and aorta.

3. In which blood vessels valves are found? What do you think is the function of valves in them?
A. Veins have valves in them. Valves regulate the flow of blood in one direction in veins.

4.Why do subcutaneous blood vessels bulge on the side away from the heart when the hand is
tied?
A. The subcutaneous blood vessels bulge on the side away from the heart because the blood is
coming from the body towards the heart.

5. Why do our legs swell after a long overnight journey in a car?

A. Our legs swell due to accumulation of lymph in the tissues. This is also called edema which is
mostly seen in old people.
6. How does lymph differ from blood?
A. Lymph is known as the tissue fluid that is blood without solid substances. Blood is the fluid
with different types of cells.
7. What happens if there are no valves in veins?
A. If valves are absent in veins the deoxygenated blood would move back and would not reach
the heart. So the cells in the legs won’t get oxygen for respiration and would eventually die due
to lack of oxygen.
8. The lumen size in vein is bigger compared to the artery. Why?
A.Blood in veins has lower blood pressure when compared to blood in artery.So it needs less
muscle tissue around the walls. Therefore its lumen is bigger than that of the artery.

9. A person is injured, his blood flows continuously. What could be the reason?
A. When a person is injured, it takes more time for blood to stop bleeding due to deficiency of
Vitamin K. Also because of genetic disorder the blood may not coagulate fast. This type of
disorder is called hemophilia.

10. Write about cardiac cycle?

A. Blood flows into auricles which are in a relaxed state from vena cava and pulmonary veins.
Then due to contraction of auricles blood flows into ventricles. Ventricles are now in a relaxed
state. After that blood flows into blood vessels like the aorta and pulmonary artery due to
contraction of ventricles.
Cardiac cycle is nothing but sequential events of relaxation and contraction of auricles and
ventricles.(systole and diastole)

11. What is single and double circulation?

A. Single circulation: Fish has two chambered heart.2.It pumps deoxygenated blood through
gills from which it is supplied to body after getting oxygenated.3.Thus the deoxygenated blood
returns to heart to be pumped to gills again.
Double circulation: In double circulation the blood travels twice through the heart in one
complete cycle. Pathway 1: Blood flows from heart to lungs and back to the heart which is called
pulmonary circulation. Pathway 2: Blood flows from heart to rest of the body and back which is
called systemic circulation. Example: Birds, amphibians, reptiles and mammals.

12. Write about hypertension?

A. If a person has high blood pressure even during resting position he is considered to have
hypertension or high blood pressure.

13. How do plants absorb water by root hairs?

A.1.Water is present between the spaces of soil particles. 2.It is absorbed by osmosis from the
soil by root hairs.3.This is passed into the xylem vessels which forms a continuous system of
tubes through root and stem into the leaves.4.Hence the water evaporates and releases into the
atmosphere.5.The evaporation creates the main pull of water above root which gives a variable
and minor push from below.6. It results in a continuous column of moving water, the
transpiration stream.
14. What is root pressure? Explain with an experiment.
A. When root hair is observed in a microscope the thin wall seen collects water to pass through
osmosis from cell to cell. It develops a pressure in xylem vessels forcing water upwards. This is
called root pressure
A regularly watered plant is taken and its stem is cut 1 cm above ground level. A glass tube of
the same diameter is connected to the stem. Level of water is marked as M1 near the stem.
After 2 to 3 hours it is observed that water level is increased to M2. Difference between M1 and
M2 gives the level of water raised in the stem due to root pressure resulting in transpiration
stream.

15. Differentiate between the following. a) arteries and veins b) systole and diastole c) systolic
blood pressure and diastolic blood pressure.
A. a) arteries and veins: Arteries: 1. Arteries carry blood from the heart to all the body parts
2.They distribute blood to the body organs.3.Blood pressure is high in arteries. 4. Valves are
absent.5.They carry oxygenated blood except Pulmonary artery.6.They are deep seated.
Veins: 1. Veins carry blood from the body parts to the heart.2.They collect blood from the body
organs.3.Blood pressure is low in veins 4.Valves are present.5.They carry deoxygenated blood
except pulmonary vein.6.They can be seen subcutaneously.
b) systole and diastole: Systole:1. It is an active phase.2.It occurs due to rhythmic contraction of
ventricles pushing the blood out of heart.3. Auriculo ventricular valves close causing lub sound.
Diastole:1. It is a resting phase.2.It occurs due to the relaxation of ventricles after having refilled
with blood from auricles.3. Systemic and pulmonary valves close causing the sound dub.
c) systolic blood pressure and diastolic blood pressure: Systolic blood pressure:1.It is the
highest force provided by the heart to move the blood into the blood vessels when ventricles
contract.2.Its value is 120 mm of Hg.
diastolic blood pressure: It is the drop in pressure in the heart when ventricles are in a relaxed
state as they are filled with blood.2.Its value is 80 mm of Hg.

Fill in the blanks:

1.Blood is low in oxygen in ______ side chambers of the heart. ( left) right)
2.__________ control the flow of blood in the heart. (Valves/Septa)
3.Outer membrane of the heart is called _______. (Pleura/pericardium)
4._______have thick walls and they carry blood from heart to body. (Arteries/Veins)
5.Heart with single circulation is present in _______. (frog/fish)
6._____ is the largest artery. (Coronary artery) Aorta)
7.Sac like a gastrovascular cavity fir digestion and transportation of nutrients is present in
______ & ______. (Hydra/earthworm/jelly fish)
8.________ is the swelling of legs due to accumulation of lymph. (Eczema/Edema)
9._________ discovered blood capillaries. (William Harvey/Marcello Malpighi)
10.How many blood vessels are attached to the heart? _____ (4 / 5)
11.________ circulatory system consists of heart, sinus and blood. (Closed / Open)
12.The blood leaving the cell tissues have a high amount of ________. (Oxygen/Carbon
dioxide/Nitrogen)
13.Heart attack is caused by blocking of ________.(coronary artery/pulmonary vein)
14.Branched digestive system is found in ______. (Platyhelminthes/Nematyhelminthes)
15.The system which is parallel to the venous system which collects tissue fluid or lymph is
______. (renal system/lymphatic system)

Chapter 4 Excretion
Objectives:
Excretion
Human Excretory System
Structure of kidney
Structure of nephron
Stages of urine formation
Uremia (End-stage renal disease) & its long term and short term solutions
Excretion in other organisms
Excretion and Secretion
Secretory products of plants
Graphic Organizer:
to remove toxins \ Excretion / to regulate the composition of body fluids
to maintain ionic balance / \ to maintain water balance

Excretion: it is the term coined for all biological processes involved in separation and removal
of waste or non useful products from the body.
Excretory substances: Waste products include carbon dioxide, water, nitrogenous compounds
(urea, uric acid and ammonia) bile pigments excess salts etc which are not useful and toxic. The
most poisonous of all is ammonia.
Human excretory system: It consists of a pair of kidneys ureters, urinary bladder and urethra.
Kidney: it is a reddish brown bean shaped structure present in the abdominal cavity attached to
the dorsal body wall on either side of backbone right kidney is slightly lower than left kidney due
to presence of liver above the right kidney.
Size & structure of kidney: Each kidney is 10cm long 5-6 cm wide and 4cm thick. It is convex
on the outer side and concave on the inner side. Inner side of the kidney has a fissure called
hilus or pelvis for the exit of renal vein and ureter and entry of renal artery. Renal artery brings
oxygenated blood loaded with waste products and renal vein carries deoxygenated blood free of
impurities. Kidney has a dark coloured outer zone called cortex and pale inner zone called
medulla.
Structure of nephron: Each kidney is made up of approximately 1 million (1.3-1.8 millions)
nephrons. Nephrons are thin tubular functional units of kidney they are also called as uriniferous
tubules..
Parts of a Nephron:

Nephron

Malpighian body (renal capsule) Renal tubule

glomerulus, bowman's capsule Proximal convoluted tubule, loop of Henle and

distal convoluted tubule

Ureter: A pair of whitish distensible muscular tubes of 30cm length. They arise from the kidney
open into the urinary bladder carrying urine from kidney to urinary bladder.

Urinary
bladder: It is a
median, pear
shaped,
distensible sac
that is present in
the pelvic part of the abdomen. It stores urine from 300 to 800 ml.

Urethra: It is a tube that takes urine from the urinary bladder to outside. It is 4cm in female and
20 cm in male.
Stages of urine formation:
Urine formation

Glomerular filtration

Tubular reabsorption

Tubular secretion

Concentration of urine
Accessory Excretory Organs:
Lungs: CO2 is excreted or exhale which is an excretory gas
Skin: Sweat sebum sterols wax and fatty acids are excreted from skin
Liver: Toxic substances, bilirubin, biliverdin (by stool).urochrome extra drugs
vitamins alkaline salts, urea, steroid, hormones etc (by urine) are excreted
with the help of liver.
Large Intestine: Excess salts, Calcium, Magnesium and Iron etc are excreted.

Uremia (ESRD): End stage renal disease is an irreversible kidney failure due
to which the body is filled with extra water and waste products.
Factors: Infections, injury, very high B.P, very high sugar.
Dialysis: Short term or temporary solution for it is 'dialysis'. The first dialysis machine was built
in 1943 by a Dutch physician Dr Willem Johan Kollff.
Kidney transplant: Long term or permanent solution for it is 'kidney transplant'. The first
attempt was done between two identical twins in 1954 by Dr Charles Hufnagel. in India it was
done in 1971 at the Christian Medical College at Vellore, Tamil Nadu.

Composition of Urine: Urine contains 96% of water, 2.5% of organic salts, 1.5% of inorganic
salts
Vasopressin hormone produces concentrated urine.
Deficiency of vasopressin produces dilute urine, a condition called diabetes insipidus
Our body produces 1.6 - 1.8 liters of urine in a day

Excretion and secretion:

Excretion is removal of waste from the body.
Secretion is formation of products at one place and their utilisation on other sites.

Secretory products of plants:

Tannins: Carbon compounds, dark brown in colour, used in tanning of leather and in
medicines.Ex: Cassia & Acacia
Resins: They are found mostly in specialized passages called resin passages mostly in
gymnosperms which contain resins. They are used in varnishes. Ex: Pinus
Gums: Sticky substance oozes out when branches are cut. They are used in making
adhesives.Ex: Neem
Latex: It is a sticky, milky substance obtained from plants. It is used for making rubber.Ex:
Hevea brasiliensis
Latex from jatropha seeds is used for making biodiesel.
Chewing gum is a type of gum made 5000 years ago. Now it is made from natural latex, chicle.
Different alkaloids and their uses:Alkaloids are nitrogenous compounds which are poisonous.
Alkaloid Plant Plant part Uses

1. Quinine Cinchona officinalis bark Antimalarial drug

2. Nicotine Nicotiana tobaccum leaves Insecticides

3. Morphine, Papaver somniferum - fruits Painkiller

cocaine opium

4. Reserpine Rauwolfia serpentina root Medicine of snake bite

5. Caffeine Coffea arabica-coffee seeds Central nervous system

influencer

6. Nimbin Azadirachta indica - seed, bark & Antiseptic

neem leaves

7. Scopolamine Datura stramonium fruit, flower Sedative

8. Pyrethroids Chrysanthemum flower Insecticide

Excretion in other organisms:

Parazoa: Ex. Amoeba, Euglena By diffusion through the body
surface.

Porifera & Coelenterata: Ex: Sponges Hydra Water washes away body cavity

Platyhelminthes &Nemathelminthes: Ex: Tapeworm and Flame cells

roundworm

Annelids: Ex: Earthworm Nephridia

Arthropods: Ex: Cockroach Green glands and malpighian

tubules

Molluscs: Snail, unio pila Metanephridia

Echinoderms: Ex: Starfish Water vascular system

Vertebrates: Fishes, amphibians, reptiles, birds or mammals Kidneys

Questions & Answers:
1. Where are the wastes produced? How are they produced?
A. Wastes are produced in the bodies of living organisms. Waste materials are produced as a
result of metabolism in the body of the living organisms.

2. Which substances present above the normal limits both in blood and urine could be harmful?
A. Blood: blood creatinine, uric acid, total cholesterol and phosphorus.
Urine: urine creatinine, Calcium, uric acid and urea.

3. Define micturation.
A. Micturation is removal of urine from the body.

4. Imagine what happens if waste materials are not sent out of the body from time to time?
A. If waste materials are not sent out of the body from time to time they accumulate in the body
and become toxic. It sometimes leads to a stage called end stage renal disease. Body will be
filled with extra water and waste products. The person feels tired and weak as his body needs
clean blood to function properly.

5. What healthy habits would you like to adopt to keep your Kidneys healthy?
A.1. Exercise regularly.2.Avoid self medication without consulting a doctor.3.Control
weight.4.Get an annual physical check up done.5.Follow a healthy diet.6.Monitor blood pressure
and cholesterol.7.Learn about kidney diseases.

6. Why is urine yellow in colour? What is its composition?

A. Urine is yellow in colour due to the presence of bile pigments and urochrome in it. It contains
96% of water, 2.5 % of organic salts and 1.5 % of inorganic salts.

7. Give reasons for the following .a) Diameter of efferent arteriole is less than that of afferent
arteriole. b) Why is more urine produced in winter? c) Why do some children pass urine during
sleep at night until 15 or 16 years of age?
A. a) For ultrafiltration to take place, there must be much pressure in glomerulus. That is why
the diameter of efferent arterioles must be less.
b) In winter as the climate is cold sweat is produced in very less quantity. So wastes are not
eliminated in the form of sweat. So to remove wastes from blood more urine is produced in
winter.
c). The lower sphincter of the urinary bladder is under the control of the brain. In some children,
this coordination does not mature fully until the age 15 to 16 years. So they pass urine during
sleep at night. Other reasons are reduced production of vasopressin hormone, heredity and
emotional and physical problems.

8. Write about the structural and functional unit of the excretory system and its function. Or
Deepak said that nephrons are functional units of the kidney. How will you support him?
A. Each kidney is made up of approximately 1 million nephrons. Nephrons are tubular functional
units of the kidney also called uriniferous tubules. It consists of a malpighian body and tubular
body that carry out formation of urine.
Stages of urine formation:
1) Glomerular filtration: Oxygenated blood with impurities flows from renal artery to glomerulus
through afferent arteriole with pressure due to narrowness of efferent arteriole. As a result it
undergoes pressure on ultrafiltration. Waste, nutrient molecules and water are filtered out by
passages between podocyte cells of Bowman’s capsule.
2) Tubular reabsorption: The peritubular blood capillaries around proximal convoluted tubule
reabsorb useful compounds like glucose amino acids etc.
3) Tubular secretion: It is the active secretion of waste products by blood capillaries into urinary
tubule or distal convoluted tubule. Waste products like urea, uric acid, creatinine, Potassium
Sodium and Hydrogen ions etc are removed.
4) Concentration of urine: 75% of water is reabsorbed in proximal convoluted tubule. 10% of
water is passed through osmosis in a loop of Henle. Further concentration of urine takes place
in collecting tubules in the presence of a hormone called vasopressin.Vasopressin is produced
when concentrated urine is to be produced.

.
9) Explain in detail the process of dialysis.
A. Dialysis machine is used to filter the blood of a person whose kidneys are damaged. Kidney
failure may be due to infections, injury, high blood pressure, high blood sugar and restricted flow
of blood to kidneys. The process is called hemodialysis as blood is taken out from the main
artery and mixed with an anticoagulant, heparin which is then pumped into the dialysis machine
In this apparatus blood flows through channels of tubes embedded in the dialyzing fluid. The
membrane which is semi permeable separates the blood from the impurities which mixes in the
dialyzing fluid. The dialyzing fluid has the same composition as that of blood plasma except the
nitrogenous waste. The waste moves freely from blood cleaning it. This is similar to the function
of the kidney but it is different as there is no reabsorption of substances.

10. Why do plants shed their leaves and bark periodically?

A. In plants waste products may be stored in leaves, bark and fruits. To get rid of these waste
products plants shed their leaves and bark periodically.

11. What precautions should be taken while observing the internal structure of a mammalian
kidney?
A. Wash the kidney thoroughly so that blood is completely drained from it.2.Keep it in the wax
tray and observe it and dissect it under the supervision of an adult.
12. Differentiate between the following. a)excretion and secretion.b)proximal convoluted tubule
and distal convoluted tubule. c) primary and secondary metabolites
a) excretion and secretion:excretion:1) Excretion is removal of waste materials from a living
being.2.It is a passive process.3.Example:tears,urine,sweat and carbon dioxide.
Secretion:1. Secretion is the movement of materials from the point of the production to the other
parts of body.2. It is in active process.3. Example: Saliva, hormones and enzymes.
b)PCT and DCT:PCT:1. It is the first part of the renal tubule.2.Proximal convoluted tubule open
into loop of henle.3.Reabsorption of minerals and water occurs here..
DCT:1. It is the terminal part of the renal tubule.2.Distal convoluted tubular opens into collecting
tubule.3.Waste like extra salts, ions of K, Na, Cl and H secretes into DCT.
c) primary and secondary metabolite: 1.primary metabolites: It is a kind of substance produced
by plants and animals which are directly involved in normal growth, development and
reproduction of organisms. Ex: carbohydrates proteins and fats
Secondary metabolite: it is a kind of substance which is produced by plants and animals which
are not involved directly in growth, development and reproduction of organisms. Ex: hormones
and enzymes

13. What discussion would you like to take about brain dead people? Why do you think so?
A. The complete and irreversible loss of brain and brain stem function is termed as brain dead.
It is like death. When the brain is injured it swells. Lungs, heart, liver, pancreas, kidneys and
intestine can be donated by the brain dead person.

14. Draw a block diagram for formation of urine.

Glomerular filtration
Tubular reabsorption
Tubular secretion
Concentration of urine
15. Where is the transplanted kidney fixed in the body of kidney failure patient? What about the
failed kidney?
A. The transplanted kidney is placed in the pelvis lower than the original place of the kidney. The
failed kidney is not removed as it produces some substances which are useful for the body.

16. Name the alkaloids which are harmful to human beings.

A. Cocaine, morphine, quinine and scopolamine can be harmful to human beings.

Fill in the blanks:

1. The structural and functional unit of the human kidney is called _______. (neuron/nephron)
2. Major component of urine is _____. (sodium/urea/water)
3. Special excretory organs are absent in_____&_____.(amoeba/birds/sponges)
4. Which of the following hormones has a direct impact on urination? (vasopressin/testosterone)
5. The alkaloid used as medicine for snake bite is ________.(reserpine/scopolamine)
6. The excretory organ in phylum platyhelminthes is __________. (flame cells/nephridia)
7. __________is a cluster of capillaries in the kidney. (Glomerulus/Calyces)
8. Nicotine is prepared from _________ of Nicotiana tobaccum. (leaves/root)
9. Urea is transported by _______. (plasma/RBC/blood)
10._______________ causes skin allergy and asthma. (Parthenium/Datura)
11. Dialysis machine was invented by________. (Dr.William John Kolff/Charles Hufnagel)
12. The alkaloid used in malaria treatment is ________. (quinine/cocaine)
13.Gums,latex and alkaloids are ___________ metabolic products of plants.
(primary/secondary)
14. The position of the right kidney is lower than the left kidney due to the presence of
________. (pancreas/liver)
15.__________ wastes are eliminated through saliva and tears. (Nitrogenous/Carbonaceous)

Chapter: 5. Coordination - The linking system

Objectives:
Types of nerve cells
Reflex action
Central nervous system
Human brain
Spinal cord
Types of nervous systems
Endocrine system in humans
Control mechanism in plants
Graphic organizer:
Types of nerves:

Neuron: There are around 100 billion neurons in humans. They are
of two types: sensory and motor. Transmission of messages takes
place from brain to body at the speed of 100m/second. No two
neurons are alike.
Discovery of types of neurons: A Greek physiologist Galen came
to know about two types of nerves, sensory and motor. A patient
came to him complaining about no senses in his arm but he could lift the arm showing normal
muscular control. According to Galen the patient who had a blow on the neck damaged the
nerve of sensation but the motor nerve had no effect as it showed its normal action.
Knee jerk activity: A person sits with one leg on the other. The upper knee is hit. The
movement of thigh muscles is observed. It shows involuntary movements. This was first
observed in 1875.Here spinal nerve pathway is involved that is operated by spinal cord.
Reflex Arc: Human Brain:
.

Human brain: it is covered

by a bony box called cranium. It has three layers of meninges in which
cerebrospinal fluid is present. It serves as a shock absorbing medium.
Brain has grey matter on the periphery that consists of nerve cell bodies
with capillaries. It has white matter in the centre which consists of
myelinated axons.
Spinal cord: It is a tubular structure arising from the hindbrain, running
throughout the vertebral column in the neural canal. It is cylindrical with
white matter towards the periphery and grey matter in the centre.

Leonardo da Vinci and Stephen Hales studied behaviour of a frog whose

brain was damaged. When it was pricked with a pointed object the frog's
muscles responded as the signals were processed by the spinal cord.
This shows that the spinal cord is not just a trunk road for instructions of
the brain but might be a control centre in its own right.
Charles Bell and Francois Magendie in the 19th century showed
functions of the dorsal and ventral roots of the spinal cord. When the
dorsal root of an animal was cut it did not show any obvious reactions but
when the ventral root was slightly touched the muscles to which it was
attached reacted violently. In 1822 they suggested that the dorsal root
carried messages inwards and the ventral pathway carried outwards the instructions for
muscular contraction.
Types of nervous system:
Central Nervous System: It consists of the brain and spinal cord.
Peripheral Nervous System: It consists of dorsal and ventral nerve cell heads, network of
spinal and cranial nerves linked to brain and spinal cord on one side and muscles of the body
on the other side. It controls involuntary actions of blood vessels, cardiac muscles and smooth
muscles. It also controls voluntary actions of some areas of skin and skeletal muscles.
Autonomic nervous system: It governs internal organs without our thinking about them. Ex:
Breathing, heartbeat, digestion and
sweating.
Sympathetic nervous system: It is a part
of the autonomic nervous system that is
formed by the chain of ganglia on either
side of the vertebral column and
associated nerves.Ex: dilates pupil inhibits
salivation, relaxes bronchi.
Parasympathetic nervous system: It is
also a part of the autonomic nervous
system formed by nerves arising from
ganglia of the brain and posterior part of
the spinal cord.Ex: constricts pupil,
stimulates salivation, constricts bronchi.
Enteric nervous system: It consists of
neurons present in our digestive tract that
can function independently of either CNS or PNS. So it is called a second brain.

Endocrine and exocrine glands:

Endocrine Glands: The secretion occurs directly into the
blood as there are no ducts.Endocrine gland secretes
hormones.Ex: thyroid gland, pituitary gland ovaries,testes
etc.
Exocrine Glands: The secretion from this gland directly
occurs in the specific site of action.Exocrine gland secretes
enzymes.Ex:liver, gastric glands, salivary glands,sweat
glands, tear glands etc.

Hormones: They are chemical substances produced in

different parts of our body that control different activities of
our body. The word hormone is derived from a Greek word
'hormao' which means 'to impel'. It was coined by Starling in
1905.The various actions of the body are controlled by
hormones and coordinated by the nervous system.
History of Insulin: In 1868 Paul Langerhans, professor of
pathology was working on structure of pancreas and noted
certain patches of cells on it different in appearance from the
normal tissue and richly supplied with blood vessels. These are known as islets of langerhans.
Insulin is produced by islets of langerhans of pancreas that control the level of free sugar in
blood and urine. The term insulin is derived from the Latin word 'insula' which means an island.
Adrenal gland: They produce adrenaline hormone which is also called the hormone of 'fight
and flight'. It is produced at the time of fear and anxiety.
Pituitary gland: It is located at the floor of the brain. It is called the master gland as many
hormones are released from it.

Phytohormones: Chemicals or hormones produced in plants that control different processes in

the plants are called phytohormones.

Types of movements in plants: Nastic Movement: Movement in plant parts without any
direction to stimuli. Ex: Folding of leaves in Mimosa pudica.

Tropic movement: Movement in plant parts in response to external stimulus is called tropic
movement. There are different types of tropic movements.
Phototropism: Growth of stem towards sunlight
Geotropism: Growth of roots towards soil or ground.
Hydrotropism: Growth of plants towards water in sea at sea shore.
Thigmotropism: Creepers grow with the help of support by touch and bound around the
support with the help of tendrils.
F.W.Went's Experiment: F. W Went conducted an experiment by taking a piece of coleoptile
(terminal portion of stem) and placing it on agar nutritive medium and cut into pieces. He placed
it on plants without a terminal portion. Agar with no contact with coleoptiles showed no bending
or little bending. The other plants with agar in contact showed bending which states that
chemical stimulus stimulated the coleoptile rather than physical stimulus. This chemical stimulus
came to be known as auxins.This was the first plant hormone discovered by F. W Went.

Questions & Answers

1. What is a synapse? How is it useful?
A. Synapse is the functional region of contact or a gap between two neurons where information
from one neuron is transmitted to another. It takes place by specialized chemicals called
chemoreceptors.

2. Describe the dimensions of the human brain?

A. Human brain weighs about 1375 gms in males and in females it weighs 1275 gms, which
accounts for 2% of the whole body weight. It uses 20% of whole body energy.

3. Define gyri and sulci.

A. The surface of cerebrum has many folds, they appear as elevations(ridges) called gyri and
depressions(grooves) called sulci.
4. Write about the parts of the human brain and their function.
A. Forebrain: It consists of olfactory lobes cerebrum and diencephalon.
1. Olfactory lobe: It is connected with a sense of smell.
2. Cerebrum: It is the seat of mental abilities. It controls thinking, memory, reasoning,
perception, emotions and speech. It responds to cold, pain and pressure.
3. Diencephalon: It is the relay centre for impulses like pain, temperature, light, muscular
activities, anger, water balance, BP, sleep and hunger.
Midbrain: It releases motor impulses from cerebral cortex to spinal cord and relays sensory
impulses from spinal cord to thalamus. It controls reflexes for sight and hearing.
Optic lobes: They control and coordinate sight.
Hindbrain: It consists of cerebellum, medulla oblongata and pons varoli.
1. Cerebellum: It maintains posture, equilibrium and muscle tone.
2. Medulla oblongata: It controls cardiac and vasomotor activities. It also coordinates reflexes
like swallowing, coughing, sneezing and vomiting.
3. Pons varoli: It regulates respiration.

5. What is the reason for folding the leaves of Touch Me Not plants when they are touched?
A. Touch Me Not plant or Mimosa pudica has pad-like swelling at the base of leaves called
pulvini. It contains a lot of water due to which the leaf is erect. When we touch the leaves an
electric impulse is generated which causes the water in the pulvini to move in the veins and
spread to the cells in the leaf. The pulvini lose its firmness and leaves become folded. After 20
to 30 minutes water comes back and pulvini gets firm making the leaf normal again.

6. Why is man called the most intelligent creature?

A. Proportionate to body size, the human brain is the largest of all animals. It is the seat of
mental abilities. The uniqueness of the human brain is it analyzes a problem and thinks of a
solution. Through his brain man has developed the ability to give a script to the sounds so that
all the information he has gathered in his lifetime is written down and passed to the next
generation. This makes man the most intelligent creature.

7.Why do plants grow near window bends?

A. The plant that is kept in a lying position near the window bends upwards towards the
stimulus, sunlight indicating the phototropic movement. The part of the plant which is in shade
produces auxins bending the plant towards sunlight.

8. What happens if anger persists for a long time?

A.If anger persists for a long period of time regular metabolic activities are disturbed.

9. Explain the role of the spinal cord in reflex action.

A. Picking up information of stimulus to generate a response involves a pathway from detector
muscles to spinal cord or from a set of nerve heads near spinal cord to the effector muscle.
Example: when you accidentally touch a very sharp surface with your feet several such are
corporate to cause the muscles to withdraw the foot.
10. Consider that you are passing by a garbage disposal area and you immediately cover your
nose .Arrange the events below in a logical order by making them from 1 to 5 to trace the
events that happened in the nervous system from detection of foul smell (stimulus generation)
to covering your nose (response).
i) At the end of the axon electrical impulse releases chemicals. ii) Stimulus received by the
dendrites of a neuron sets off chemical reactions that create an electrical impulse. iii) Electrical
impulse transmitted through the cell body and axon. iv) The chemicals cross the synapse and
reach the next neuron. Similarly the electrical impulse crosses several neurons. v) Finally the
impulse is delivered from the neuron to the gland that helps in recognition of the foul smell and
muscle cells that help in covering the nose.
A.1. ii 2. iii 3. i 4. iv 5.v

11. State whether the following actions are voluntary action, reflex action or conditioned reflex.
A. i) Blinking-Involuntary action ii) Cleaning the table-voluntary action. iii) Playing on the
keyboard-conditioned reflex. iv) Salivating when food is put in the mouth -conditioned reflex v)
We close our ears when we hear unbearable sound-voluntary action.
12. Why are pancreas called both an exocrine and an endocrine gland?
Pancreas releases pancreatic juice through pancreatic duct into the duodenum which helps in
the digestion of different nutrients.It also releases a hormone called insulin through islets of
Langerhans and pour it directly into the blood. Therefore the pancreas is called an exocrine as
well as an endocrine gland.
13.Differentiate between the following. a) hormone and enzyme b)stimulus and response
c)sensory and motor nerves d) exocrine and endocrine glands e) thigmotropism and
thigmonasty
A. a) hormone and enzyme: hormone:1. Chemical substances secreted by endocrine
glands.2.They do not act as catalyst.3.They coordinate body functions.
enzyme: 1.They are proteinaceous substances produced by mostly exocrine glands. 2.They act
as catalyst by helping in digestion.3.They do not coordinate body functions.
b) stimulus response:Stimulus:1. It is a signal from an external or internal environment.2.It is
carried by sensory nerves to the brain or spinal cord.
Response: 1.It is the reaction due to the stimulus. 2.It is carried by motor nerves from the brain
or spinal cord to the body.
c) sensory and motor nerves: Sensory nerves:1. They are also known as afferent nerves.2.They
carry impulses from sensory organs to the brain.3.They receive information from outside and
send them to other neurons.
Motor nerves: 1. They are also known as efferent nerves.2. They carry impulses to the muscles
from the brain.2.They receive information from other neurons and send to effectors to produce a
response.
d) exocrine and endocrine glands: Exocrine glands: i) These glands have ducts to carry their
secretions to other parts. Ex: salivary glands, lachrymal glands, sweat glands.
Endocrine glands: These are ductless glands that secrete their secretions directly into blood.
Ex: adrenal gland and thyroid gland.
e) thigmotropism and thigmonasty: Thigmotropism:1. Response is seen towards a support in
some plants that grow with the help of stimulus by touch. 2. Movement in plants is seen in a
particular direction. Example: Creepers
Thigmonasty: 1. Response is seen in some plants with the stimulus of touch. 2. Folding of
leaves is seen in plants without any direction. Example: Mimosa pudica (Touch Me Not) plant.

14.What happens if all the functions of the body are controlled only by the brain?
A. If all actions of the human body are controlled by the brain, our body will get harmed in
dangerous situations. 2. Some actions may be delayed and our brain could not conduct reflex
actions, which require immediate action to a stimulus.

Fill in the blanks:

1.________ stops its function if a person has lost control of emotions. (Cerebrum/Cerebellum)
2._________ is responsible for closing of stomata. (Abscisic acid/Ascorbic acid)
3. __________ response is seen in Touch Me Not plant. (Thigmotropism/Thigmonasty)
4. Diabetes is related to _________gland. (pancreas/pituitary)
5.________ phytohormone promotes cell division. (Cytokinins/Gibberellins)
6. Pollen tube travels towards ovum representing ________.(chemotropism/phototropism)
7. Iodine is necessary for the secretion of ______hormone. (adrenaline/thyroxine)
8. _________ maintains poster, equilibrium and muscle tone. (Cerebrum/Cerebellum)
9._________ regulates heart beat, vasomotor and respiratory activities. (Cerebellum/Medulla
oblongata)
10.___________ are the three membranes which cover the brain. (Pericardium/Meninges)
11. There are ______ pairs of cranial nerves. (12 / 31)
12. __________ is responsible for general growth rate and metabolic activity.
(Adrenaline/Thyroxine)
13. Reflex arc is controlled by________ (Brain/Spinal cord)
14. The hormone which increases the fertility in male is called_______.
(oestrogen/testosterone)
15. Junction between two neurons is called _______. (Synapse/Neural joint)
Biology Class 10 Chapter 6: Reproduction
Objectives:
Reproduction-Its factors
Types of reproduction
Human reproductive system
Cell division - Mitosis & Meiosis
HIV - AIDS
Contraceptives
Social evils - Female foeticide & Teenage motherhood
Reproduction: The process of producing offspring to continue life.

Factors of Reproduction:
Environment:Curdling of milk: It takes place by lactobacillus bacteria in a warm environment. The
bacteria require two to three hours to multiply for curd formation.
Time: In paramoecium two types of reproduction are seen.
Binary fission: Paramoecium splits into two in binary fission during favourable conditions.
Conjugation: Two paramecia come closer, exchange their body materials and separate and then divide
into two in conjugation. This takes place during unfavourable conditions.
Reproduction: The process of producing offspring to continue life.
Types of reproduction: Asexual and sexual reproduction
Asexual reproduction: Reproduction involving a single parent which results in identical offspring.
Sexual reproduction: reproduction involving two parents with formation and fusion of male and female
gametes to form offsprings.
Types of asexual reproduction: Fission: It is seen in single celled organisms which divide into two or
more offspring. Ex: Amoeba, Paramoecium.
Budding: Small identical structures called buds are formed on the parent's body and separate and live
independently. Ex: Yeast, Hydra.
Fragmentation: New organisms are formed from the fragments or pieces of the parent's body and
separate and live independently. Ex: Tapeworm, lichens, mould, spirogyra.
Regeneration: Body of an organism is broken into pieces. Each piece develops into an individual
organism. Ex: Planaria
Parthenogenesis: It is the process where the female gamete develops into a zygote with desirable
characters. Ex: seedless fruits of watermelon and grapes.
Honey bees and wasps undergo parthenogenesis. The fertilized egg converts into a female. The
parthenocarpic zygote converts into a male. .

Reproduction in plants: Vegetative propagation: Reproduction involving vegetative parts of plants is

called vegetative propagation.
Leaves: New plants grow at the margin of some plants. Ex: Bryophyllum
Bulbil: Small bulb arising from leaf axil or in the place of a flower (which grows underground). Ex: Onion
(with adventitious roots) Adventitious roots: Roots growing in unusual locations.
Stem: Tuber: Fleshy underground stem grows into a new plant. Ex: potato
Corm: Bulb shaped solid stem serving as a reproductive part. Ex: colocasia, yam
Stolon: Horizontal branches producing new plants from buds. Ex: Strawberry, grass
Roots: Guava, murraya, millingtonia
Artificial propagation: It is the propagation of plants by vegetative parts carried on artificially.
Cutting: A small piece of a stem is cut from the parent plant and is inserted or buried in the moist soil. It
grows into a new plant. Ex: Rose, mint, hibiscus etc
Layering: When a branch of a plant with at least one node (point from where leaf arise) is bent towards
the ground and covered with moist soil leaving the tip exposed, adventitious roots develop from buried
part. The branch that is bent is cut off and grows into a new plant. Ex: Nerium, Jasmine.
Grafting: It is used to obtain desirable characters when two plants are joined together. Ex: Mango, apple,
rose etc.
Tissue culture: A few plant cells or a plant tissue is taken in a growth medium (agar) with plant
hormones produces a mass of cells called callus. Tiny new plants arise from callus. Thousands of new
plants are grown in a very short time. This is a commercial process using modern technology to feed the
growing population. Ex: Banana, pineapple, orange grapes, rose etc.

Spore formation: Rhizopus (bread mould) produces hundreds of microscopic reproductive units called
spores. When the sporangium breaks in favourable conditions (damp) they germinate and produce new
individuals. Other organisms producing spores are ferns, mosses, mucor and bacteria.

Sporophyll: Fern plants have clusters of dot-like structures called sporangia. These contain spores. The
leaf of a plant with sporangia is called sporophyll.

Activity:1. Aim: To prepare the slide of a rhizopus and examine it under a microscope.

Precautions: Transfer the sample carefully on the slide avoiding contact by wearing gloves. Remove
excess water from the slide by pressing it with a cover slip slightly. Handle the microscope with correct
adjustments to observe the sample. Avoid direct contact on skin and do not inhale it as it is allergic.

Procedure: Place a drop of water on the slide. Prepare bread mould slides by transferring a little sample
with forceps on the slide. Spread it with the help of another slide lightly. Add a drop of glycerin. Place the
cover slip and set it at an angle to the slide. Avoid air bubbles. Blot up excess water or glycerin using
tissue paper.

Observations: The common bread mould consists of thread-like projections called hyphae and thin
knob-like structures called sporangium which contains hundreds of spores.

Human Reproductive System: Male reproductive system: (1) a pair of testes,(2) vasa efferentia, (3) a
pair of epididymis, (4)a pair of vasa deferentia, (5) a pair of seminal vesicles, (6) ejaculatory duct, (7)
prostate gland,(8) a pair of Cowper’s gland, (9) urethra.

I) Testes : The testes are located outside the abdominal cavity within a pouch called scrotum. In each
testis highly coiled seminiferous tubules which produce a large number of sperms are produced in these
tubules by meiosis (hundreds of millions).Male sex hormone testosterone is also produced in testis. The
scrotum helps in maintaining low temperature of the testis(2/2.5oC lower than the body temperature)
necessary for sperm formation.
ii) Vasa efferentia : The seminiferous tubules open into vasa efferentia to carry sperm into the
epididymis.
iii) Epididymis : It is a highly coiled tube located along the posterior side of the testes that stores sperms.
iv) Vasa deferentia : From each epididymis a vas deferens arises which ascends into the abdominal cavity
looping around the ureter.
v) Seminal vesicles : They open into the vas deferens. They produce seminal fluid which is the source of
energy for sperm.
vi) Prostate gland: Prostate gland secrete prostate fluid which is one of the components of semen, it
supplies nutrients to the sperm.
vii) Cowper’s gland : Secretions of these glands help to neutralize the acidity in the walls of urethra and
the free flow of the sperm cells.
viii) Ejaculatory duct: A duct from seminal vesicles joins the vas deferens and continues as ejaculatory
duct. Two ejaculatory ducts join at the centre urethra.
ix) Urethra : In male it transports not only urine but also sperms. It is also called a urinogenital duct.
x) Semen: Secretions of glands together with sperms is called semen.

Female Reproductive System: It consists of a pair of ovaries, oviduct and uterus. Ovary has graafian
follicles which produce egg or ovum. When an ovum is mature, a follicle ruptures and releases the
ovum.This is called ovulation. The ovum passes through the oviduct or fallopian tube where it is fertilized
by a sperm. The fertilized egg passes through the oviduct to uterus and it is embedded there where the
embryo is provided its food and disposes its waste. Uterus becomes thick, soft and richly supplied with
blood for the embryo to be implanted.

Menstrual cycle: If the ovum is not fertilized, the uterus sheds its layers, ovum ruptures and menstrual
cycle begins.
Fertilization: When the ovum is fertilized, it is embedded in the uterine wall. During development of
embryos, tiny finger-like projections develop from the outer surface called chorion, small pools of blood
and tissue of chorion make up the placenta after 12 weeks of pregnancy. The blood system of mother
and baby are separated by membranes made up of cells that allow the exchange mainly by diffusion of
oxygen, carbon dioxide, nutrients and waste materials.
Amnion is another embryonic membrane around the embryo filled with amniotic fluid which keeps it
moist and protect it from minor mechanical injuries.Allantois is the membrane which originates from
alimentary canal of embryo forming umbilical cord which is connected to placenta. From the third month
of pregnancy the embryo is called a fetus. After 280 days or nine months, which is the gestation period,
the baby is delivered by contraction and relaxation of muscles of the uterus.
Gestation period: It is the average length of pregnancy.63 day-cats and dogs; 330 days-horse; 280
days-cows; 280 days-humans; 20 to 22 days-rats and mice.
Internal fertilization: It is seen in mammals where the zygote develops in the mother's womb. Ex:
human beings.
External fertilization: It is mostly seen in water animals. Frogs and fish release sperm and ova in water.
Some of them unite to form young ones.
Sexual reproduction in plants: Reproduction in plants takes place through stamens(male gametophyte)
and carpels(female gametophyte) present in a flower.
Double fertilization: Reproduction in plants takes place through double fertilization where two sperms
from pollen grain enter into the female gametophyte fertilizing ovum and polar nuclei.
Fusion of egg with sperm cell is fertilization after which a zygote is formed. Zygote divides several times
to form an embryo within the ovule.Second sperm unites with polar nuclei forming endosperm tissue
which stores food for the development of ovule. Ovule develops a tough coat and converts into a seed
and the ovary converts into a fruit.
.

Cell division: Continuation of life and growth are due to cell division in cells of body and gametes. There
are two types of cell division. Mitosis and meiosis.
Theories about cell division: Virchow gave the phrase (omnis cellula de cellula) which means new cells
arise from preexisting cells.
Robert Remark published his observations on cell division by observing embryos. He stated that binary
fission causes reproduction or division of animal cells.
Walter Fleming (1879) examined many kinds of animal and plant cells that undergo division. He observed
that there are strings like structures inside the cell that divide longitudinally. He named that process of
division as mitosis which means fine threads. A decade later these threads were named as chromosomes
which mean coloured bodies. When observing the nucleus he used dye to stain these structures.
Wilhelm Roux (1850-1924) proposed that these structures carry heritable characters and longitudinal
splitting ensured equal division of these characters.
Augustus Weisman proposed that in successive generations individual species have the same number of
chromosomes. In successive cell division the number of chromosomes always remains constant.

In 1904 Theoder Boveri proposed the scheme of mitotic division.

Mitosis: It has four stages.

Prophase: During prophase chromosomes contract, become visible, split lengthwise, nuclear membrane
breaks down, and centrosomes form spindles.
Metaphase: Chromosomes move to the spindle equator; centromeres are attached to spindle fibers
which split separating chromatids.
Anaphase: Spindle fibers attached to centromeres contract pulling chromatids towards poles.
Telophase: Chromatids elongate; become visible; nuclear membrane forms; cell membrane divides
nucleus into two; division of cytoplasm starts.

Interphase: The period between two cell

divisions is called interphase. It has four
stages. They are: G1 phase: Linking period
between completion of mitosis and
beginning of DNA replication. (10.5 hrs)
S phase: Period of DNA synthesis leading
to its duplication.(10.5 hrs) G2 phase: The time period between end of DNA replication and beginning of
mitosis.( 3.5 hrs) M phase: Mitotic cell division phase. (1hr)

Meiosis: It is the process of cell division where haploid cells are formed with half the number of
chromosomes in daughter cells. Meiosis occurs in formation of gametes in sexual reproduction. Meiosis
has two phases.

In the first phase the parent cell divides with exchange of chromatin material (crossing over). In the
second phase division is exactly like mitosis but chromosomes do not duplicate and forms four daughter
cells with half the number of chromosomes.
HIV: Human Immunodeficiency Virus
AIDS: Acquired Immunodeficiency Syndrome
HIV is a retrovirus that damages the T-cells in blood, deteriorating the immune system of a human body.
Mode of transmission: Blood, reproductive secretions, infected syringes, from mother to child, infected
blood transfusion. It was recorded in 2011-12 that A.P has the highest number of HIV positive patients.
Reasons for spread of HIV: Illiteracy, poor health, unemployment, migration, unethical contacts,
nontraditional sex and trafficking.
Control measures: Government established Anti Retroviral Centre (ART) to supply medicines for HIV
patients. An organization like Accredited Social Health Activist (ASHA) is established. Red Ribbon Express
Club is a program to create awareness in people.
Prevention: i) Avoid unethical practices. ii) Use of contraceptives. iii) In case of doubt, the patient needs
to go to a qualified doctor for early detection.
Contraceptives: The prevention of pregnancy in women by preventing fertilization is called
contraception. Ex: Physical devices like condom and diaphragms. Pills for males and females which
contain certain hormones kill sperm in male and prevent ovaries from releasing ovum in females.
Intrauterine device called copper-T.
Surgical methods: Vasectomy: A small portion of vas deferens or sperm duct is cut and removed and
tied, it is called vasectomy. Tubectomy: A small portion of oviduct (fallopian tube) is cut and both the
ends are tied together which prevents ovum from entering oviducts. This is called tubectomy.

Fighting against social evils: Female foeticide: Killing female foetus in mother's womb is called female
foeticide. Due to this male-female gender ratio is declining at an alarming rate. In some sections of our
society our government has already laid a ban on determination of sex of foetus. It is our responsibility
to stop female foeticide.

Teenage motherhood: To become a mother, a woman has to understand and get prepared for such a
responsibility. She must have a matured mind and body which is possible only after 18 years of age.
According to the department of family welfare 21% of teenage mothers die during delivery. So, girls
below 18 years of age should not be married.
Questions & Answers
1. How does formation of bacterial colonies take place in milk?
A. One teaspoon of curd is added to a bowl of milk which is lukewarm. Lactobacillus bacteria start
multiplying, converting the milk into solid curd in a few hours.
2. How does potato reproduce?
A. Potato tuber is an underground modified stem which has buds or potato eye. Farmers cut this eye or
sucker part and plant it in the soil which germinates soon into a new plant.

3. Name the process of reproduction involved in production of seedless fruits.

A. Parthenogenesis is the process involved in production of seedless fruits. In this process the female
gamete develops into a zygote with desirable characters.

4. Explain the process of grafting.

A. Two plants are joined and grown into a new plant. The plant that is on the lower side with root is
called stock. The one on the upper side without root is called scion. Both stock and scion are tied with
the help of a twine thread and covered with a polythene cover. Grafting is used to obtain desirable
characters. Example: mango, apple, rose.

5. Why do fish and frogs produce a large number of eggs every year?
A. In animals like fishes in frogs, fertilization takes place externally in water where meeting between egg
and sperm is very difficult. So, they produce a large number of gametes as at least some of them may
meet for fertilization. That is why they produce a huge number of eggs and sperms.

6. Why is the fertilization in plants called double fertilization?

A. In flowering plants, pollen grains fall on the stigma of the flower. A Pollen tube develops and enters
the female gametophyte carrying two sperms. After fertilization of an egg cell by one sperm another
sperm unites with the centrally located polar nuclei. This forms a nutritive tissue called endosperm. The
egg cell converts into zygote which forms the embryo (seed) in the ovule. This type of fertilization is
called double fertilization.

7. What is the function of endosperm in the female gametophyte?

A. Endosperm provides food for growing embryos in the female gametophyte of a flowering plant.

8. What precautions would you take while observing rhizopus (bread mould) in the laboratory?
A. 1.Transfer the sample carefully on the slide avoiding contact with it by wearing gloves.2. Don’t inhale
the sample especially people with allergy and asthma.3.Remove excess water from the slide by pressing
the cover slip avoiding air bubbles.

9. Mention the function of placenta and amniotic sac for the developing foetus in the mother's womb.
A. Placenta: It helps in absorbing nutrients and oxygen from the Mother's blood and supplies them to
the fetus. At the same time excretory products and carbon dioxide formed in the foetus are transported
in the Mother's blood for elimination through placenta.
Amniotic sac: Amniotic sac contains amniotic fluid which gives protection to the embryo against minor
mechanical shocks and keeps it moist.
10. What precautions should be taken to keep away from sexually transmitted diseases?
A. The following precautions should be taken to avoid sexually transmitted diseases: 1. By adhering to
moral values.2. By avoiding unethical practices 3.By using contraceptives. 4. By giving proper treatment
to infected pregnant mother.5.By using disposable syringes and sterilized needles.

11. How will you appreciate cell division that helps in perpetuation of life?
A. 1.Cell division is the process that transforms a human fertilized egg into a baby.2.It is a highly
regulated function in multicellular organisms. 3. Mitotic division results in continuous growth of
organisms throughout their life.4. It also contributes to the repair of body organs. 5. Moreover, cells in
some organs such as the heart and brain of an adult never divide whereas cells in bone marrow divide
actively to produce red blood cells.
12 How do you observe pollen grain in a lab?
A. A slide is taken with a drop of water on it. Anther of the flowers is tapped on the slide. Small drop-like
structures are seen. They are pollen grains. Observe under compound microscope.

13 Differentiate between a) asexual and sexual reproduction b)mitosis and meiosis.

A. a) asexual and sexual reproduction: Asexual reproduction: 1.t involves a single organism. 2.No
production of gametes.3.There is no fusion of gametes.4.It requires only mitotic division.5.It produces
offsprings that are identical to parents.6.Asexual reproduction is not very useful for natural selection in
evolution of species 7.In asexual reproduction chances of genetic variations are only through random
mutations.8.It occurs by budding, fragmentation and sporulation.
Sexual reproduction:1.It involves two organisms.2.Male and female gametes are produced3.It involves
fusion of male and female gametes.4.It requires meiotic division followed by mitotic division.5.Offsprings
will have some characters from male and some from female parent some characters may not be present
in either of the parent.6.Sexual reproduction is highly useful for natural selection in evolution of
species.7.In this there is more chance of genetic variations.8.It occurs due to pollination and fertilization.

b) mitosis and meiosis: Mitosis:1.It occurs in somatic or body cells.2.Two daughter cells are
formed.3.Nucleus divides once.4.Daughter cells are deploid.5.No crossing over takes place. 6.Exchange
of genetic material does not take place.7.It has a short duration.8.The whole process completes in one
sequence.
Meiosis:1.It occurs in germ cells.2.Four daughter cells are formed.3.Nucleus divides twice.4.Daughter
cells are haploid.5.Crossing over occurs in chromosomes.6.Exchange of genetic material occurs between
non sister chromatids.7.It has a long duration.8.The whole process completes in two successive stages.
Fill in the blanks:
1.______ produces eggs in the female reproductive system. ( ovary/cervix)
2. Sperms are produced by _______ in male reproductive system. ( seminiferous tubules/vas deferens)
3. _____ is the third stage of Mitosis. (Metaphase/Anaphase)
4. In plants fusion of male gamete with secondary nucleus results in ______. (endosperm/cotyledons)
5. ______ has division less cells. (Brain/Lungs)
6. Propagation of new plants takes place through_______ in Bryophyllum. (leaf/stem)
7. Spore formation is the common method of asexual reproduction in ________. (hibiscus/ferns)
8. Meiotic division takes place in______ cells. (somatic/germ)
9. Fetus is attached to mother through ________. (umbilical cord/placenta)
10. Placenta is formed after ______ weeks of pregnancy. (8 / 12)
11. ______ is the contraception method related to males. (Tubectomy/Vasectomy)
12. Pollen grains germinate only on the _______.(stigma/ovary)
13. Binary fission occurs in _______. (Euglena/Hydra)
14. Fertilization in human beings occurs in _______. (uterus/fallopian tube)
15.__________ is an asexual method that involves separation of a branch that touches the ground from
the parent plant. (Layering/Grafting)

Chapter 7 Coordination in Life Processes

Objectives:
Taste
Smell
Dentition
Passage of food through
oesophagus
Passage of food through stomach
Passage of food through intestine
Second brain

Hunger: When glucose level falls in your body it results in hunger pangs. Diencephalon and Vegas nerve
plays an important role in carrying the signals to the brain. Ghrelin is a hormone released in the stomach
which initiates hunger. Leptin hormone suppresses hunger.
When a new dish is offered, we see it, smell it and then taste it. Smell and taste are related. When
someone has a cold they can neither smell nor taste food.

Types of tastes: Sweet, salty, savory, bitter, hot, spicy and savory( metallic proteinaceous taste). Savory
taste is present in monosodium glutamate and protein food.
If we want to taste food, it has to be taken in mouth, chewed to mix saliva so that the flavor enters into
the pores and reaches taste buds. From there it reaches the brain through a nerve called the hotline.

Activity 1: Role of palate in tasting food:

When few sugar crystals are put on tongue kept outside the mouth we would not feel the taste unless
our tongue is pressed by the palate and sugar enters our taste pores and reaches our taste buds.

Activity 2: Cumin and fennel

When cumin seeds are chewed and after that fennel seeds are chewed we are able to differentiate
between the taste.
Smell: There are chemoreceptors (proteins) in the nose that react with molecules of vapors of smell in
air then we are able to smell different things.
Sometimes our mouth waters by thinking about food items or hearing their names.
Evan Pavlov conducted an experiment where a dog was trained to salivate by just hearing the bell which
was a sign for arrival of food
The arrangement of teeth in the mouth of human is called dentition

Dentition formula: 2:1:2:3(x4) 8:4:8:12=32

An adult human has 32 teeth. In children there will be 28 teeth, 4
wisdom teeth come later.
Incisors- 8
Canines- 4
Premolars- 8
Molars- 12

Coordination in tasting food:

Activity 3: Breakdown of food: Pieces of chalk dissolve faster in vinegar than a big chalk which shows the
importance of mastication. Mastication take place in mouth which is a munching machine

Mastication: Grinding and shredding of food is called mastication. Teeth and tongue help in
mastication.Oral muscles help in moving food in all corners of mouth. Lower jaw moves up and down
with the control of cranial nerves.

Activity 4: Action of saliva on wheat flour:

Procedure: Take two test tubes,put water in both till half their
volume. Add little wheat flour in both test tubes. Now in test tube 1
add a spoon full of saliva. Do not add anything in test tube 2. Now
keep them aside for about an hour or so.
Observation: After 45 minutes test the contents of both the test tube
with iodine. Contents of test tube 2 turns blue black but no change in
color is seen in test tube 1.
Result: This is because starch is converted into glucose due to action
of saliva in test tube 1.
Activity 5: Testing the PH of mouth:
pH: It is the power of Hydrogen ions which determine the nature of a
substance.
Procedure: Take a pH strip and put it on your tongue soon after a
meal. Compare the color of pH paper with pH scale. The value
determines the acidity or basicity of the mouth.
Salivating during a nap in day time: Our salivary glands produce 1-1.5 litre of saliva per day. When we
take a nap during daytime, saliva oozes out of the mouth as our digestive system is active during the day
because humans are diurnal animals.
Passage of Food through Oesophagus:
Oesophagus: Inner walls of oesophagus have circular
muscles that contract narrowing oesophagus just
behind bolus (ball like food that enters food pipe from
mouth). Outer walls of the oesophagus have
longitudinal muscles that contract widening the tube
shortening that part of the oesophagus. When bolus
passes through oesophagus it aids its easy movement
due to lining of mucus.
Activity 6: Potato and cycle tube
When a greased potato is passed through a cycle tube
which is also greased by oil, it shows the movement of bolus through the
oesophagus. Contraction and relaxation of muscles of oesophagus carry
peristalsis which is under the control of involuntary action of autonomic
nervous. system

Passage of Food through Stomach

When food is taken in the mouth the nerves of tongue and cheeks and signals
to brain, then the message is transmitted from brain to stomach which
stimulate gastric glands. The walls of the stomach produce hydrochloric acid
and gastric juice. The effect of HCl is prevented on stomach walls by production
of mucus from walls of the stomach.

Activity 7: Role of Mucus in Protecting Stomach:

Two leaves are taken and one of them is
greased with petroleum jelly. Both the leaves
are exposed to a few drops of an acid. The
greased leaf is not affected by the acid but
the leaf which was not greased turns pale.
This experiment shows the action of mucus
on the stomach wall.
Chyme: The vigorous contractions of stomach
muscles squeeze and mix food with HCl which
turns the food into smooth porridge called
chyme. Stomach is called the mixer and
digestor
Steps involved in digestion of food in the stomach:
Propulsion: Movement of food from one part of stomach to the other due to peristalsis.
Grinding: The most vigorous peristalsis and mixing occurs at pylorus (lower part of stomach).
Retropulsion: Small amount of chyme is pushed into duodenum simultaneously forcing the remaining
amount back into the stomach.
Rumination: Animals like cows and buffaloes bring back their bolus from a part near the stomach into
their mouth. It is called reverse peristalsis.
Human stomach is like a pouch which is elastic in nature that increases its size depending upon the
amount of food taken.Digestive juices are produced depending on the quantity of food material taken.
Passage of Food through the Small Intestine: Food is a
soup-like mixture when it leaves the stomach into the intestine.
Its acidic nature initiates production of hormones called
secretin and cholecystokinin that stimulate the pancreas, liver
and intestine to produce their secretions. The finger-like
projections called villi in the small intestine help in increasing
the area of absorption of digested food in the small intestine.
Intestinal juice is called succus entericus.
Activity 8 - Model of villi in small intestine.
Make two paper rolls of different diameters. Fix the bigger role
in the smaller one to observe a wavy structure of villi in the
small intestine.
Passage of food through the large intestine: Undigested food is passed from small intestine to
large intestine where maximum water is absorbed and solid waste is moved to rectum. Left side of the
colon (rectum) acts as a storage tank for feces which is expelled by anus. There are two muscular
sphincters, one is under involuntary control and the other is in voluntary control which helps in opening
and closing of anus. Hence digested food is oxidized by respiration, nutrients are transported to various
body parts by circulation throwing waste outside the body. .

Digestive tract or gut as second brain: Our digestive tract is a unique organ exposed to a variety of
physico chemical stimuli. It is coordinated with muscular apparatus and neural apparatus for appropriate
mixing and propulsion.Our digestive system is called the second brain as it is composed of a network of
100 millions of neurons. 70% of our immune system is aimed at the gut to expel and kill foreign invaders.
Stimulative coordination, breaking down of food, absorbing nutrients, expelling waste involved in
mechanical mixing and rhythmic muscle contraction that move everything down the line. Second brain
controls many gut functions independent of the brain.

Answer the following questions:

1. Which system in the body is called the second brain?
A.The digestive tract is a unique organ because it is exposed to a variety of physico chemical stimuli from
the external world in the form of ingested food. The neural Apparatus of the digestive tract comprises a
vast network of hundred million neurons so it is called the second brain. The second brain plays an
important role in the immune system,it expels or kills foreign bodies.

2. Why is the stomach shaped like an elastic bag rather than a tube?
A. The stomach is shaped like an elastic bag for the following reasons: 1. It has to accommodate varied
quantities of food. 2.Food has to be stored for a longer time in the stomach.3.,Most of the digestion
takes place in the stomach producing acid.

3. A boy felt hungry but relaxed after sometime.Why?

A. Ghrelin is the hormone that initiates hunger and leptin suppresses it.

4. Which part of the small intestine absorbs food?

A. In the small intestine there are numerous finger-like projections called villi. They increase the surface
area so that the food is retained in the folds longer and gets absorbed.
5. Name the chemical for testing action of saliva on wheat flour.
A. Iodine is the chemical used for testing action of saliva on wheat flour.

6 Why can't we identify the taste of food when it is very hot?

A. If we want to taste the food it must have the temperature nearer to the body temperature. If the food
is too hot or cold the papillae in the tongue won't function as thermoreceptors function at that time.So
we cannot identify the taste in the food when it is too hot.
7. We feel hungry when glucose level falls.Why?
A. Starch is converted into glucose in the digestive tract. If glucose level falls there is no sufficient starch.
So hunger pangs send communications to the brain. Now the brain commands the stomach to produce a
hormone ghrelin which causes hunger.So we feel hungry.
8. What is the length of the small intestine? Name its parts.
A. The length of the small intestine is around 6 meters. It has three parts: duodenum,jejunum and ileum.

9. Describe an activity to show the importance of mucus protecting the stomach from the effect of
hydrochloric acid.
A. 1.Two leaves are taken2.One of them is greased with vaseline.3.Both the leaves are exposed to a few
drops of a weak acid.4.The greased leaf will not be affected by acid showing the action of mucus on
stomach wall protecting it from acid.

10. Differentiate between mastication and rumination.

A. Mastication: 1. The process of chewing food in the mouth using teeth and tongue.2.This takes place in
human beings.
Rumination: 1. The process of bringing back hurriedly chewed food from the rumen by reverse peristalsis
and chewing it thoroughly and swallowing again.2.This takes place in ruminants like cow and goat etc.

Fill in the blanks:

1. ________ sphincter helps in the opening of the stomach into duodenum. (Cardiac/Pyloric)
2. _________ is the region in the brain that controls hunger signals. ((Cerebrum/Diencephalon)
3.In human dental formula 2: 1: 2 :3 , 1 denotes ______. (canines/ premolars)
4. The hormone released during hunger is_____. (ghrelin / leptin)
5. Pepsin is released by _______. (stomach/small intestine)
6. When we feel our stomach is full and there is no need for food _____ hormone is secreted.
(ghrelin/leptin)
7. The strong acid which is secreted into the stomach with gastric juice is _____. ( HCl/HNO3)
8. The muscles that help in food in the mouth are ______.(circular/longitudinal)
9. Acidic nature of chyme initiates the production of hormones like ________&__________.
(secretin/ trypsin/cholecystokinin)
10. For the digestion to occur in the food canal coordination of ________ & ________processes are
necessary. (coordination /excretion/circulation)
11._______ cranial nerve which is also called vagus nerve plays a major role in carrying the hunger
contractions. (5th / 10th )
12.Olfactory receptors are present in _____. (tongue/nose)
13. _______ plays a major role in identifying taste. (pharynx/palate)
14. The other name of the second brain is ______ nervous system. (enteric/sympathetic)
15. Mastication means ________ & _________ of food. (chewing/churning/grinding)

Chapter 8: Heredity
Objectives:
Heredity & Inheritance
Variations
Mendel’s Experiments
Mendel’s Laws
Structure of DNA
Sex Determination in Humans
Darwin’s & Lamark’s Theories
Evolution - Macro and Micro
Homologous & analogous organs
Fossils
Human Evolution
Human - a moving museum
Heredity: Transmission or passing of characters from parents
to offsprings.
Inheritance: The process in which traits are passed from one
generation to another.
Characters or traits: Specific features of a person.
Example:Height, complexion, shape of ear etc.
Factors or alleles: Sets of contrasting characters.
Example:Tall-short, Fair-dark, etc.
Variations: Differences in characters between very closely
related members of a group are called variations.
Parents and offsprings are similar in some characters but have
some new characters too.
Gregor Mendel: In 1857, Mendel who was a monk carried out
experiments on pea plants in his monastery. He worked on
10,000 pea plants with 34 different varieties.
Pure breed and mixed breed:
Pure breed: Plants that have the same factors in their characters in coming generations. Example:Tall
plants (TT), Yellow seeds (YY)
Mixed breed: Plants that have two different factors in a character of coming generations. Example: Tall
short (Tt), ( T-Tall(dominant) t- short (recessive)
Yellow green (Yy) Yy Y-Yellow(dominant y- green (recessive)
Mendel's Experiments: Cross pollination of plants with yellow and green seeds was done in F1
generation.

On self pollination of F1 generation plants, the offspring in F2 generation had 75% yellow seeds and 25%
green seeds.

Self Pollination in F2 Generation Self pollination in F3 Generation

On self pollination of F2 generation the offspring in F3 generation had 25% yellow seeds,out of 50%(75%
yellow seeds and 25% green seeds), 25% only green seeds.
Homozygous offsprings: A zygote formed by fusion of two gametes having identical factors is called
homozygous organisms. Example: TT, tt, YY etc.
Heterozygous offsprings: A zygote formed by fusion of two gametes having different factors is called
heterozygous organisms. Example: Tt, Yy etc.
Phenotype ratio: In F2 generation, it is the ratio of characters of organisms based on external
appearance. It is 3:1, where three are dominant and one is recessive.
Genotype ratio: In F2 generation, it is the ratio of characters of organisms based on genetic makeup.It is
1:2:1 where one is pure dominant, two are mixed dominant and one is pure recessive.
Monohybrid ratio: In this ratio only one character is considered.So this is
called monohybrid ratio. Example: Height/colour of seed.

Dihybrid ratio: In this ratio two sets of characters are considered. So this is
called the dihybrid ratio. 9:3:3:1
Round Yellow - 9
Round green - 3
Wrinkled Yellow - 3
Wrinkled green - 1

Mendel's Laws:
Law of Dominance: The dominant characters are expressed when
factors are in heterozygous condition.
Explanation: Among a pair of closely related factors only one
expresses itself in the first generation as one factor is dominant over
the other. This is called the Law of Dominance. Example: Rr, Yy
Law of Segregation: Characters segregate during
gamete formation.
Explanation: Every individual possesses a pair of
factors or alleles for any particular trait or
character.Each parent passes a randomly selected
factor of only one of these to an offspring. Thus the
offspring receives its own pair of alleles for that
particular trait, one from each parent.
Law of Independent Assortment: The factors
independently assort and combine in different
combinations.
Explanation: The factors for each pair of characters
are independent of the other pair.This is law of
Independent Assortment.Ex: RrYy
Verification of Law of Dominance: This activity shows different probabilities of factors combining to
form different traits8 strips of blue colour (4 big 4 small) and 8 strips of pink colour (4 big 4 small) are
taken into different bags and are named as male and female parents. Everytime one strip is picked from
each bag to form a pair for a particular character.
Chromosomes carry genes. Gene is a segment carrying DNA.
DNA- Deoxyribonucleic Acid: DNA controls the expression of traits or characters. DNA is a double helix
structure discovered by Watson and Crick. Any change in its chemical nature leads to variations.

Activity:
Aim: To observe the structure of DNA with a DNA molecule model.
Apparatus: DNA model.
Content: DNA molecule looks like a spiral
staircase having a shape known as double helix.
The framework of the staircase consists of
alternate sugar and phosphate groups and the
steps which join the framework together are the
pairs of chemical compounds called bases. They
are adenine, thymine, cytosine and guanine.
Traits are determined by the chemical nature of
DNA. A slight change in them leads to changes in
the traits of offsprings. Such changes are called
variations. In 1953 the detailed structure of DNA
was worked out at Cambridge by Francis Crick and James Watson. They were awarded the Nobel prize
jointly with Franklin and Maurice Wilkins.
Evolution: Evolution is a slow and continuous process. It was proposed by Charles Darwin through his
theory called Natural Selection which means
that nature only selects which organisms should
survive or perish in nature.This means 'Survival
of the Fittest.'
Variations are caused due to sexual
reproduction and errors in DNA in the offspring
of a population. Variations which are useful to
an individual retain and which are not useful
are lost.So in a population when there is a
struggle for existence the fittest will be
survived.
Situation 1: Due to variations 1 out of 12 red
beetles become green. Green hides in leaves
from predators and increases in number.
Population of green beetles increases.
Situation 2: Due colour variations as beetles
reproduce sexually 1 blue beetle is produced in the
red population. Red were stamped by elephant foot
thus resulting in an increase of blue beetles.
Situation 3: Due to plant disease, leaves were
infected. The beetles starved, decreased in weight but
their genetic material did not change. Low weight is not an inheritable
character.
Charles Darwin: Charles Darwin was born in England, voyaged for five
years by the ship named HMS Beagle. He visited Galapagos Island when he
observed a small group of related birds with diversity in structure of
beaks.
He also proposed that large changes occurred due to accumulation of
small changes leading to evolution. Darwin was also influenced by
Malthus theory which suggested that population grows in geometrical
progression(1,2,4,8) and food sources increase in arithmetic progression(1,2,3,4,5).
Jean Baptist Lamarck: Lamarck was the first person to propose the theory of evolution. He proposed
that the giraffe's neck elongated over a period of time to reach the leaves on the top.
These characters are acquired by offspring. This is called Inheritance of Acquired
Characters'.
Augustus Weisman disproved Lamarck's theory by removing tails of parental rats for 22
generations but still offsprings were normal with tails.

Homologous and Analogous Organs:

Homologous organs: A common pattern in the arrangement of bones, though the external forms and
functions are different. Such organs are called homologous organs.
Ex: Hand of a human - grasping
Forelimb of a cheetah - running
Fin of a fish - swimming
Claw of a mole - digging
Wing of a bird - flying

Analogous organ: These organs look similar as they have a common function but they differ in their
structural components. Such organs are called analogous organs.
Ex: Feathers of an insect
Feathers of a bird
Patagium of a bat
Fossils: Fossils are evidence of ancient life forms or ancient habitats which have been preserved by
natural processes. They are typically preserved within the sediments deposited beneath water and land.
They can be actual remains of bones and seeds or dinosaur footprints or ripple marks of a prehistoric
shore.If a dead insect gets caught in mud, it will eventually harden and not decompose quickly and the
mud will eventually harden and retain the impression of the body.The study of fossils is called
paleontology. Paleontologists determine the age of a fossil by carbon dating method.
Carbon dating method: This method was developed by Willard Libby in 1940 who received the Nobel
prize for it in 1960.Measuring the amount of 14C carbon in a sample from a dead plant or animal
provides information that can be used to calculate when the animal or plant died.
The older the sample the less 14C is detected.
Age of a Fossil=[Ln Nf/No] t1/2
0.693
Connecting link(Archaeopteryx): The organism which bears the characters of two different groups is
called the connecting link. Ex: Archaeopteryx
Archaeopteryx has some avian and some reptilian characters.

Evidence of Embryology: In the embryos of different

animals from fish to man, the resemblance is so close that
at an early stage even an experienced embryologist would
find it difficult to distinguish one embryo from the other.
This strengthens the view of evidence of a common
ancestor from which all these have evolved.

Human Evolution: Human race came from Africa

as our genetic footprints can be traced back to African
roots. The migrants slowly spread to Asia,
Indonesia,Philippines, Australia and America.
Human being - a moving museum: some organs which are not useful in animals are called
vestigial organs. Human beings have 180 vestigial organs. So he's called a moving museum.
Ex: Ear pinna, hair on skin and appendix in intestine etc.

Questions & Answers

1. Why did Mendel use a pea plant for his experiment?
A. Mendel used a pea plant in his experiment for the following characteristics.1.Well defined
characters.2.Bisexual flowers. 3. Predominantly self fertilization. 4. Early hybridization.

2. Explain phenotype and genotype ratio.

A. Phenotype ratio: It is the ratio of offsprings in plants showing external
characters. It is 3:1 where 3 tall plants and 1 short appear in F2 generation.
Genotype ratio: It is the ratio of offsprings in plants showing genetic
constitution. It is 1:2:1,where 1 is pure tall,2 are mixed tall and 1is short
plant appears in F2 generation.
3. Explain sex determination in humans with a flowchart. (Or)
Which chromosome is for sex determination in humans?
A. There are 23 pairs of chromosomes in a human cell. Out of which 22 pairs are
called autosomes. One pair is called allosome, which determines the sex of the
offspring. In females both allosomes are denoted by XX. All the ova produced by a
woman will be with only X chromosomes. In males the allosomes are X and Y
chromosomes. If a sperm with X chromosome fertilizes an ovum with X
chromosome, the resultant baby will be with XX condition. So it will be a girl. If a
sperm with Y chromosome fertilizes an ovum with X chromosome, the resultant
baby will have XY condition. So it will be a boy. Therefore the sex of the baby is
determined by the father.

4. State the Mendel's laws.

A. Law of dominance: The dominant characters are expressed when factors are in heterozygous
condition. Example: When a tall and a short plant are crossed, the offspring will be tall showing tallness
is a dominant factor in the character of height.
Law of segregation: Characters segregate during gametes formation. The offspring receives its own pair
of factors for that particular character, one from each parent. Example: An offspring receives a factor of
tallness from father and shortness from mother forming Tt character.

Law of independent assortment: The factors for each pair of characters assort independently of the
other pair. Example: An offspring receives a factor of tallness and shortness from each parent for the
formation of height character; factor of fairness and darkness from each parent for character of colour
complexion etc.

5.A scientist cuts the tails of rats for one parental generation. Do offspring of rats have normal tails or
not .Write your opinion?
A. Offspring of rats will have normal tails because bodily changes are not inherited. So such changes
won't be passed to offspring.
6. What is paleontology? What does it deal with?
A. The study of fossils is called paleontology. It deals with fossils, which are ancient life forms and ancient
habitats which have been preserved by natural processes.

7. Define the following.1) gene 2) genome 3) genetic drift

A.1) gene: A gene is a sequence of DNA or RNA which codes for a molecule that has a function. DNA is a
chemical basis of heredity.DNA is in genes. Genes are on chromosomes.
2) genome: A complete set of genes present in one haploid set of chromosomes is called a genome.
3) genetic drift: Sometimes accidents change the frequency of genes in small populations. This is known
as genetic drift.
8. Write the postulates of Darwin’s Theory.
A. Darwin’s Theory: 1.Any group of organisms develop variations and all members of groups are not
identical. 2. Variations are passed from parents to offsprings through heredity.3.The natural selection
over abundance of offsprings leads to a constant struggle for their survival in any population.
4.Individuals with variations that help them to survive and reproduce tend to live longer and have more
offsprings. 5. Evolution is a slow and a continuous process.

9. Differentiate between 1) macroevolution and microevolution 2) homologous and analogous organs.

A.1) microevolution: Small changes within the species leads to microevolution. Example: Few green
beetles in a population of red beetles
macroevolution: When few members of a species isolate from the group and are introduced into a new
environment, they adapt themselves to the new conditions forming a new species. Example: Few beetles
carried away by birds in their beaks.

2) homologous organs: A common pattern in the arrangement of bones, though the external forms and
functions are different. Such organs are called homologous organs.
analogous organs: These organs look similar as they have a common function but they differ in their
structural components. Such organs are called analogous organs.
Fill in the blanks:
1 The Origin of Species was written by ________. (Charles Darwin/ Charles Lyell)
2. The scientist who studied rats by cutting the tails is ________.(Augustus Weisman/Jean
Baptist Lamark)
3. The wings of a bat and wings of a bird are the examples of ______ organs.
(homologous/analogous)
4.______ is a segment of DNA. ( Gene/Genome)
5. The sex of a female child is determined by _____ chromosome in a sperm. ( X / Y)
6. In Mendel's monohybrid cross the phenotype ratio in F2 generation is _____ (3:1 / 1:2:1)
7. According to Mendel _________ character is expressed in F1 generation. (
recessive/dominant)
8. Sex of a baby depends on the gamete of a _______. (mother/father)
9. ________ in offspring are caused by sexual reproduction or errors in DNA copying.
(similarities / variations)
10. The book Principles of Geology was written by ________.(Charles Lyell / Malthus)
11._______________________ explains only one of the two factors for a character passes from
parent to offspring. ( Law of Dominance / Law of Segregation)
12. Chromosomes whose number and morphology do not differ between male and female of a
species are called _________. (autosomes / allosomes)
13. Elongation of neck and forelimbs in giraffes is an example for __________. (Survival of the
Fittest / Inheritance of Acquired Characters)
14. Carbon dating is used to determine the age of a ________. (fossil / fetus)
15. Fossils of the dinosaurs, ketosaurs are collected from __________ district. ( Adilabad /
Medak)

Chapter 9: Our Environment - Our Concern

Objectives:
Environment - its parts
Food chain
Food web
Ecological pyramids
Pyramid of number
Pyramid of biomass
Pyramid of energy
Story of Kolleru Lake
EBWR case study
Sparrow Campaign
Important points:
Environment: The sum of physical and biological factors along with chemical interaction forms
the environment.
Biosphere: The place where organisms live is called biosphere. All components of the
biosphere interact in an organized manner with the organisms.
Ecosystem: A region with a specific type of condition within the biosphere is called an
ecosystem. There are a number of ecosystems with variations in climatic conditions.

The main climatic influences which determine the conditions of these ecosystems are rainfall,
temperature, availability of light from the sun.
Food Chain: The relationship between organisms and their food , forms a food chain.
A food chain shows how energy is transferred from one organism to another.
At each transfer a large portion (80-90%) of the energy is dissipated as heat produced during
respiration and other ways.

Food Web: When food chains are interconnected, a food web is formed.
Niche: Animals fit into special positions within the food web which is called their niche.
Niche not only denotes the animal’s position in the food web but also its food and its mode of
life.

Ecological Pyramids: Pyramids are another type of

representation which shows flow of energy from one organism to another. It is the graphic
representation of the feeding level of an organism by taking the shape of a pyramid. Each level
in a pyramid is called trophic level. This method of representation was first introduced by a
British ecologist,Charles Elton in 1927.

Types of Ecological Pyramids:

Pyramid of Number: It represents the number of
organisms at each trophic level. It has producers (plant
leaves), then primary consumers (aphids) then secondary
consumers (lady bugs) then it has tertiary consumers
(insectivorous birds) and finally top carnivores (eagle/hawk)
at the top of the pyramid.
Biomass: Any type of plant or animal material that can be converted into energy is called
biomass.It is the organic material of biological origin that is derived from fixation of carbon
dioxide and trapping solar energy by photosynthesis.
Ex: Trees, shrubs, crops, grasses, algae, aquatic plants, agriculture and forest residues and all
forms of human, animal and plant waste.
Biofuels: When these materials are used for energy production, they are called biofuels.
To reduce dependence on fossil fuels like coal, petrol etc and reduce pollution,biomass can be
used as an energy source.
It will put carbon dioxide back into the atmosphere in the same amount as that used when this
biomass was produced.
Pyramid of Biomass: In this pyramid we find biomass at each trophic level.When animals eat
only a small amount of food it is converted into tissue which forms food for the next trophic level.
Most of the biomass that an animal eats is either not digested or it is used to provide energy as
they are inefficient in converting maximum food into biomass.
It is found that 10 to 20% of biomass is transferred from one trophic level to the next. Almost
90% of food is lost at each trophic level.
Inverted Pyramid: In aquatic ecosystem when the biomass of each individual in a trophic level
is considered then the pyramid of biomass will be an inverted one.
Pyramid of Energy: The energy produced by sunlight, carbon dioxide and water is needed by
all living things which is prepared by photosynthesis. Food is provided to consumers by green
plants. Green plants get energy from sunlight. Food has chemical energy stored in the form of
potential energy.

Flow of Energy: Organisms

lose some biomass by death,
disease or annual leaf drop
after which the materials flow
back into the environment. The materials keep on cycling.
Story of Kolleru Lake: Kolleru Lake is situated between West
Godavari and Krishna districts of Andhra Pradesh. It is the
largest freshwater lake extending up to 612 sq. km. In
November 1999 the government of AP declared the lake as a
bird sanctuary.It hosts 193 species of birds, a variety of flora
and fauna including medicinal plants. 20 lakh migratory birds
from North Asia and Eastern Europe visit here between October
and March. It has 20 million residents living in that area. It is a
sweet water lake shrunk in size, facing greater threat due to
pollution as revealed by satellite pictures.
Aquaculture was started in the 80's. In 1966 the entire lake was brought under cultivation. Due
to excessive nutrient addition because of the development of agriculture and industry,explosive
growth of weeds is seen in the lake. Water became more alkaline in nature, with low dissolved
Oxygen and high BOD (biological oxygen demand). Diseases like typhoid, diarrhoea and
amoebiasis were common in inhabitants. Prawns and fish were affected by the disease. The
Ministry of Environment and Forest, Government of India constituted a committee 'Operation
Kolleru' to protect the lake.

Observe the given table and answer the following questions:

1.In which year Lake water spread area is more and why?
A.In 1967 Lake water spread area was more as the lake had not shrunk and also due to
absence of weeds.
2.Why do you think there are more weeds in the lake?
A.Due to decrease in water spread area and increase in rice fields, fertilisers are drained into
the lake leading to increase in weeds.
3. What are the reasons for the decrease in the lake area?
A.Increase in weeds, rice fields, human settlements and global warming.
4.How do the above reasons lead to pollution?
A.Due to human activities like farming, industry, human habitations, pollution increased.
5.How was the threat to the lake due to pollution discovered ?
ABy measuring the lake water spread area with the help of satellite pictures. In 1999 the
government discovered the threat of pollutants.So it was declared as a bird sanctuary.
6.What would be the reason for migration of birds?
A.Sweet water resource, pleasant weather, food availability and increase in weeds.

Observe the above table and answer the following questions:

1.What are the factors that have affected the number of migratory birds to decrease?
A.Aquaculture activities.
2.Do you find any relationship between biological and physical problems.
A.Both problems are due to aquaculture practices and human activities
3.What are the reasons for chemical problems? A. The reasons are aquaculture and agriculture
practices and industrial and human activities. 4.What happens if the dissolved oxygen is
reduced in lake water?
A.It affects the growth of flora and fauna in the lake.
5.Is BOD of turbid and nutrient rich water high or low? What are its consequences?
A.Biological Oxygen Demand (BOD) of turbid and nutrient rich water is high. It results in
decrease of growth of flora and fauna.
6. People living in the catchment area of Kolleru faced so many problems. Why?
A.Due to increased pollution people suffered from water borne diseases like typhoid, diarrhoea
and amoebiasis.Prawns and fish were also affected by disease.
Effects of Farming and use of pesticides:
When a forest is cut, dynamic equilibrium of a vast variety of species is replaced by monoculture
(single crop) in fields of agriculture.
Indiscriminate use of pesticides destroys vast numbers of animals.
Nondegradable pesticides accumulate in bodies of animals and pass through the food web. Ex:
Mercury, Arsenic, Lead
Bioaccumulation: The process of entry of pollutants into a food chain is known as
bioaccumulation.
Biomagnification: The tendency of pollutants to concentrate as they move from one trophic
level to the next is known as biomagnification.
EBWR - A case study:
Seasonal bioaccumulation of heavy metals in Cyprinus carpio fish
is of Edulabad Water Reservoir
Deterioration of water in reservoirs through heavy metal contamination
and organic pollutants is mainly due to industrialisation and
anthropogenic (caused by human) activities. Fish are considered to be
bio indicators of metal contamination. A study of EBWR showed
enrichment of heavy metals such as lead(Pb) cadmium(Cd) chromium
(Cr) manganese (Mn) Nickel (Ni) and ferrum (Fe) contamination due to
industrial and agriculture effluents. Cyprinus carpio is a cheap and
highly proteins fish found in EBWR, Ranga Reddy was taken as a
sample for its various tissues like liver, kidney and gills. A parallel study was conducted in water
samples and fish of the reservoir of Bibinagar, Nalgonda. Study revealed higher
bioaccumulation and lower glycogen and lipid content in fish of EBWR. The metal concentration
in EBWR was found to be higher than Indian standard limits in the following sequence.
Fe>Pb>Cr>Ni>Cd.
Bioaccumulation of these metals in fish tissues was in the following sequence.
Cd>Cr>Fe>Ni>Pb
The heavy metals find their way into human beings through the food chain causing various
physiological disorders such as hypertension, sporadic fever, renal damage and nausea etc.

Answer the following:

1.How can you say fishes living in water have heavy metals in their bodies?
A.This happens due to bioaccumulation and biomagnification as a result of pollution due to
industrial and agricultural effluents.
2. Where do pollutants enter into the water resource from?
A.Urban development, unorganized small scale industries and agriculture farms.
3.Researchers found that pollution levels decreased during monsoon season. Why do
they find so?
A.During monsoon season more water accumulates in water bodies which result in decrease of
concentration of heavy metals in water.
4.Why do people also suffer from various diseases after consuming fish living in local water
reservoirs?
A.Due to bioaccumulation of heavy metals the fish is polluted which is consumed by people
harming them. The reason for this is agricultural effluents, industrial waste and acid rains.
Changes in natural ecosystem due to human activities:
Due to changes some plants and animal species will die out. Some will adapt to the new
conditions to survive but in reduced numbers.
Some will benefit by new conditions and will increase in number.
Minamata disease: This was first discovered in Minamata city, prefecture in Japan in 1956. It
was caused by the release of methyl mercury in wastewater which bioaccumulated in shellfish
and other fish which was eaten by local people resulting in death due to mercury poisoning for
36 years.
Sparrow Campaign:
With the intention of rapid increase in industrial production, one of the famous initiatives China
took in 1958 was to form cooperative or collectives of up to 5000 families which yielded double
the amount of crops grown. After a year of successful harvest fewer crops were harvested in the
following year due to bad weather. This led to an imbalance between demand and supply. The
sparrows were accused of pecking away at the supplies in the warehouse. At an estimated rate
of 4 pounds of grains per sparrow per year people started trapping, poisoning and killing
sparrows in large numbers. Sparrow nests were torn down, nestlings were killed. Later some
scientists cut open the digestive system of dead sparrows, informed that three fourth of the
contents were of insects harmful for crops and only one fourth content was of grains. Sparrow
was basically a beneficial bird eating locust insects. Increased population of locusts with bad
weather led to the great Chinese famine. Use of pesticides against the locust population further
degraded the land.
Read the about passage and answer the following questions:
1. What is the food chain that has been discussed in the above case?
A.Grains—--> Locust —----> Sparrow
2.How did the campaign disturb the food chain in the field?
A.With no sparrow to eat the locust the population of locusts increased damaging the rice crops
severely.
3.How did the disturbance affect the environment?
A.Due to the increase of locust population, pesticides were used adding pollution leading to
degradation of land.
4. Is it right to eradicate a living organism in an ecosystem? How is it harmful?
A It is not right to eradicate living organisms in an ecosystem as food chains get affected
causing an imbalance in the ecosystem.
5. Were the sparrows really responsible? What was the reason for the fall in crop production?
A.No, sparrows were not responsible. The reasons for fall in the crop production were increased
locusts population and bad weather.
6. What was the impact of human activities on the environment?
A. Due to careless killing of sparrows, the locust population increased. To reduce locusts
population pesticides were used.This resulted in degradation of land, food crisis developed and
people migrated to other areas.
7.What do you suggest for such incidents not to occur?
A. A detailed study of the actual cause should be done and required steps must be taken to
solve the problem.
Steps towards prevention:
i) Rotation of crops - growing different crops in successive years to reduce pests. ii)Studying
the life history of pests - to study the stages in their life cycle and understand how pests
spread and reduce damage to crops iii)Biological control- introducing natural predators for
pests
iv)Sterility - rendering male of pests species sterile
v)Genetic strains - development of genetic strains of plants resistant to pests
vi)Environmental ethics - following what is right and what is wrong concerning the
environment.
Fill in the blanks:
1. What does a food chain always start with? __________ (herbivore/producer)
2. Entry of pollutants into the food chain is ________. (bioaccumulation/biomagnification)
3. Arranged the following in a correct sequence.
(Snake, Frog, Plants, Hawk, Grasshopper)
______ _______ _______ _______ _____
4. The continent without a forest is _______.
(Arctic/Antarctic)
5._______ refers to the position in the food chain. ( Niche/Trophic level)
6. The concept of ecological pyramid was proposed by _______ (Charles Elton/ Lindeman)
7. The population of organisms in each trophic level is represented in _________ (pyramid of
number/pyramid of biomass)
8.In an aquatic ecosystem the pyramid of biomass is (upright / inverted)
9. An example of artificial ecosystem is ________ (grassland/ cropland)
10. What percentage of energy is transferred from one trophic level to the next in a food chain?
_____ (10% / 20%)
11. ________ is the organic material of biological origin. (Biomass/Biogas)
12.Air, water, soil, sunlight are called ______factors. (biotic / abiotic)
13. Kolleru Lake discharges its water into the Bay of Bengal through the ______ channel (River
Narmada / River Godavari)
14. The tendency of pollutants to concentrate as they move from one trophic level to the next is
___________. (bioaccumulation/ biomagnification)
15.The diseases caused due to bioaccumulation of metals through food are _________.
(sporadic fever/ hypertension /renal damage/ all the above)

Chapter10: Natural Resources

Objectives:
Comparative study of two villages - Wanaparthy & Vaddicherla
Community based interventions
Farmer based interventions
Sustainable Development
Forest, Soil, Biodiversity, Fossil fuels & Minerals
Conservation - Reduce, Reuse, Recycle, Recover
Important points: Survey of two villages Wanaparthy and Vaddicherla, of Jangaon district of Telangana
was conducted. The first one had no scarcity of water and the second one with scarce groundwater. The
reason was Wanaparthy had a percolation tank and the village had higher household income
Percolation tank: Percolation tanks are earthen dams with masonry structures where water overflows
with cut off trenches below the earthen dams. It is properly compacted to achieve stability. Outlets for
surface irrigation are made. Construction material consists of a mixture of soil, silt loam, clay, sand,
gravel suitably mixed and laid in layers at the base or bed and sides.

Observe the above table and answer the following questions:

1.What is the total irrigated area in acres in Wanaparthy village?
A.Total irrigated area is 1000 acres.

2.If one needs to irrigate all the land in Wanaparthy, how many wells would be required?
A No. of wells = 155
Total land 1000 sq m
No. of wells = 155
= 4000 X 155/ 1000 = 4 X 155 =
= 620 wells.

3.Will the area under irrigation change due to the rise in population? Why or why not?
A.Yes, the area under irrigation will change due to the rise in population as two three farmers
have to divide the same field of their father.

Observe the given table and

answer the following questions:
1.A well irrigates more area in kharif
season as compared to Rabi. How is
it possible?
A.Kharif season is the rainy
season.So the groundwater is
replenished and so a well irrigates more area in that season.
2.How should a farmer utilize such a condition?How can wells be recharged?
A.He has to harvest the rain water so that the groundwater is replenished and the water table is
increased
3.If a well can irrigate 2.5% of cultivable land, how many wells would irrigate the whole of the
land?
A 2.5 % —----- 1 well
100 % —------- ?
1000/25 = 40 Approximately 40 wells are required.
4.Which factor has a greater effect on expenditure, the number of wells or depth of water?
A. Both the number and depth of the well.
5.What is the total expenditure on a small irrigated land owned by a farmer in Vadicherla?
A.The total expenditure by a farmer in Vadicherla is 20000 to 45000 rupees.
6.What would help the small farmers reduce expenditure? (Hint: think of crops that require less
water)
A.The crops that require less water and less maintenance can be grown to reduce its
expenditure. Ex:lemon, broccoli, millets etc.

7.Do you think the depth of borewell is a good solution for increasing total land area under
irrigation?
A.Yes, if the depth of the borewell is increased the total area under cultivation can be
increased.The groundwater level should be increased.

Observe the above table and answer the following questions:

1.Which crop is the most profitable for a farmer in Vadicherla?
A.Paddy in kharif season is the most profitable crop for a small farmer.
2.What is the difference between a farmer in Wanaparthy and Vadicherla with small land
holdings?
A.The income per acre in rupees varies for a farmer in both villages and also the small farmer
in Wanaparthy get more profit in growing cotton and those in Vadicherla get more profit in
growing paddy in kharif season.
3. Which crop could replace paddy and be more profitable as well for a farmer in Wanaparthy?
A. Cotton is more profitable.
4.Though we know that paddy consumes maximum water why do you think farmers still like to
grow paddy?
A.The demand for that will always be more.
5.What is the impact of depleting resources upon the farmers?
A.If a resource is depleted the farmers cannot grow crops, the produce is reduced.
6.Do you think the income of a farmer with small land holdings in Vadicherla is sufficient enough
to meet his expenditure?
A.No, it is not sufficient.
7.Do you think farming as an occupation is profitable for small farmers in Vadicherla?
A.No, it is not profitable.
8.Would the farmer have to look for other kinds of occupations to meet his needs?
A.Yes, the farmer has to look for other occupations to meet his needs.

Center for World Solidarity: It is a project that addresses sustainability of groundwater

intervention to help in recharging wells that are drying up in villages. It is located in
Secunderabad,Telangana. They encouraged farmers to share water, adopt techniques like drip
irrigation, sprinkler irrigation and also helped in construction of soak pits to tap rain water. Dykes
and barriers were also built in underground streams to tap
groundwater optimally.
Water for all: 95% in seas and oceans
25 to 27% freshwater
1.75 to 2 frozen water
0.7 to 0.8 groundwater
0.01 in ponds, lakes, swamps

Kothapally village: A survey of this revealed it had dryland

areas, literacy was low, labor was scarce, more fertilizers
and pesticides were used, crop yield was low, and there
were no water harvesting structures.
ICRISAT: International Crop Research Institute for Semi-Arid Tropics educated villagers in large
numbers and provided technical support for cost efficient water and soil conservation structures.
Following measures were taken.

Community based Interventions: 14 storage structures with 300 - 2000 m3 storage capacity
were constructed. 60 mini-percolation pits and field bunding on 38 hectares were completed. 28
dry open wells were recharged by building dykes or barriers in the nearby canals for retaining
rain water in them.
Farmer-based Interventions: Measures implemented in individual fields were broad bed
furrows in the field, constructing canals around fields and constructing landforms useful for
water conservation. Farmers used water resources jointly and used techniques like drip
irrigation which can reduce water consumption upto 70% but could irrigate only 2% of land
around the world.
Wasteland Development and Tree Plantation: Useful plant species were planted along the
roads, field bunds and canals. Trenches at 10 m intervals with 0 3 m height of bund were laid
out. Custard apples along with other useful species were planted in trenches and Gliricidia
( madri, a leguminous plant) were planted on field bunds to strengthen and make the soil
nitrogen- rich. 2500 fruit trees and teak plants were planted.

According to a survey conducted in 2004 total amount of water available in Telangana and
Andhra Pradesh is 3814 thousand million cubic feet of which
Irrigation 2268 TMC
Domestic Use 21 TMC
Industries 10 TMC
Power generation 1 TMC
Total amount utilized 2300 TMC
Amount required for utilization by 2025 is 3989 TMC.

Sri Rama Sagar Project: It is also called Pochampadu Project on Godavari river. It is the lifeline
for large part of Telangana with a capacity of 80.66 TMC(Thousand million cubic feet)

Source of Irrigation water: We have seen major consumption of water in the farming and
industrial sector. In spite of major rivers like Godavari and Krishna, the major source of irrigation
is groundwater.
According to the United Nations Development Program, water resources in an area where
annual water supply drops below 1700 m cube per person is becoming scarce. The Food and
Agriculture Organisation of the United Nations has predicted that by 2025 1.8 billion people will
be living in countries or regions with absolute water scarcity.

Natural Resources Around Us: The earth's natural resources include air, water, soil, minerals,
fuels, plants and animals. Some of these natural resources can be replaced after they are used
and are called renewable resources. Some other resources cannot be replaced such as fossil
fuels once they are used, so they are called non renewable resources.
Some people often waste natural resources. Animals are over hunted, forests are cleared
exposing land to wind and water damage. Fertile soil is exhausted and lost to erosion because
of poor farming practices. Fuel supplies are depleted, water and air are polluted.
Water use restrictions are implemented in many regions of the world. In Australia due to
chronic shortage of water resulting from drought, restrictions are imposed on activities like
watering lawns by sprinklers, washing vehicles, using hose pipes to clean paved areas and
refilling swimming pools.

Sustainable development: Development and conservation of natural

resources can co-exist in harmony when we use the environment in ways
that ensure we have resources for the future, it is called sustainable
development.

Forest - an important renewable resource:

They provide us with innumerable products. In an urge to extract them
we discriminately destroy them. Deforestation destroys wildlife habitat and increases soil
erosion. It also releases greenhouse gasses into the atmosphere. Every continent except
Antarctica has forests. Forests serve as lungs for the world and a bed of nutrients for new life to
prosper. Amrita Devi and her daughters followed by villagers who clung to trees in the forest
surrounding their village and laid down their lives to save them. Chenchu and Gond tribes of our
state are aware of extracting resources from nature carefully and adopt ways that help revive
them.
People in China and Mexico, for example, reuse much of their waste paper including writing
paper, wrapping paper and cardboard. If half of the world's paper is recycled, much of the
world's demand for new paper would be fulfilled, saving many trees.

Soil: Soil is vital to food production. It is important to plant that grows in the wild. Plant
conservation and animal conservation depend on soil conservation. Poor farming methods such
as repeatedly planting the same type of crop in the same place deplete nutrients in the soil. Soil
erosion by water and wind increases when farmers plough up land on hills. One soil
conservation method is contour strip cropping. Several crops such as corn, wheat and clover
are planted in alternating strips across the path of the prevailing wind. Mature commercial trees
of a specific diameter are harvested on a rotational cycle to maintain ecological balance. This is
called selective harvesting. Harvested areas are then closed for a prescribed period of time
before the next harvest cycle in the same area. This provides younger trees a chance to grow to
full commercial potential. This allows a forest to regenerate naturally.

Biodiversity: It is a variety of living things that populate the

earth. We need a rich mixture of living things to provide
food, building material and medicines as well as to maintain
a clean and healthy landscape.Through hunting, pollution,
habitat destruction, people are speeding up the loss of
biodiversity at an alarming rate. We need to protect
biodiversity to ensure plentiful and varied food sources. We
use thousands of plant species for medicine worldwide. Parks and sanctuaries to protect wildlife
and the habitats are there in many states in India. They all work to abolish hunting practices that
may cause extension of many species.

Fossil fuels: Fossil fuels are produced from the remains of ancient plants and animals. They
include coal, petroleum oil and natural gas. Apart from their use in vehicles, many products that
are made from petroleum are plastics, synthetic rubber, fabrics like nylon, medicines, cosmetics,
waxes, cleaning products, medical devices etc. We need to conserve fossil fuels as we may run
out of them even though they are the reason for pollution. Scientists are exploring alternatives to
fossil fuels. They are trying to produce renewable biofuels to power cars and trucks. They have
successfully produced electricity using energy from sun, wind and water etc. Everyone can help
conserve fossil fuels by using them carefully, by purchasing energy efficient appliances, walking
for small distances, riding a bicycle and using public transportation whenever possible.
Seeds of Jatropha curcas plant are used for the production of biofuel as a crucial India's plan to
attain energy sustainability. Andhra Pradesh and Telangana had made a formal agreement with
Reliance industries for jatropha planting and had selected 200 acres of land at Kakinada to grow
jatropha for high quality biodiesel.

Minerals: Many mineral deposits that have been located and mapped have been depleted. As
the ores for metals like aluminum and iron become harder to find and extract, their prices go up.
This makes tools and machines more expensive to purchase and operate. Mountaintop
Removal Mining devastated the environment. This destroys soil, plants and
animal habitats. Other mining methods also pollute water and air as toxic
chemicals leak into the surrounding ecosystem.
In Japan car manufacturers recycle many raw materials used in making
automobiles. In the United States nearly 1/3rd of the iron produced comes
from recycled automobiles.

Conservation - a vital concern: The Indian tradition teaches us that all

forms of life - human, animals and plants are so closely interlinked that
destruction of one gives imbalance in the other. Small steps could become
great efforts at conservation. The 4 R's save the environment. They are
Reduce, Reuse, Recycle, Recover.
Reduce: You can save water by repairing leaky taps and avoiding a shower
or conserve electricity by switching off unnecessary lights and fans.
Reuse: Things that you often tend to throw away like paper and wrapping paper, should be
reused.
Recycle: It may not always be a very good option as recycling plastic is a tricky process and
can cause havoc, since each type can be recycled with its own kind, plastic needs to be
carefully stored before they can be processed.
Recover: When we cut trees to construct industries, for roads, for transportation etc, it is
important to grow trees in another area.
Conservation groups: Governments enact laws defining how land should be used and which
areas should be used as parks and wildlife preserves. Governments also enforce laws to protect
the environment by establishing factories to install pollution control devices. Finally governments
often provide incentives for conserving resources. Many international groups also work to
conserve resources.
The International Union for the Conservation of Nature is an alliance of governments and private
groups founded in 1948. In 1980 the group proposed a world conservation strategy. It monitors
the status of endangered wildlife, threatened national parks and preserves and other
environments around the world. The IUCN works to protect wildlife and its habitats.

Fill in the blanks:

1. ___________ tank helps to preserve rainwater. (Overhead / Percolation)
2. _________development means development without damaging the environment.
(Sustainable/Temporary)
3. The reason for farmers growing _______ is to make soil nitrogen rich. (gliricidia/ guava)
4. Bishnoi tribe belongs to the state ___________. (Gujarat / Rajasthan)
5. Fossil fuels were produced from the remains _____ & _____. (plants/birds/animals)
6. Farmers were provided technical support for cost efficient water storage and soil conservation
structures by ________.( IRRI / ICRISAT)
7. Chipko movement is associated with _____.(tiger/ trees)
8. _______ tribe belongs to our state who are well aware of identifying medicinal plants and
picking them without harming them. (Chenchu / Gonda)
9. _________ plants are used for production of biofuel. (Bamboo / Jatropha)
10. In order to increase groundwater the method to be adopted is _________. (digging water
harvesting pits / urbanization)