S.

NO CHAPTER NAME PAGE NO

1 THE BIOLOGY

2 BIOLOGICAL MOLECULES

THE ENZYMES
3
THE CELL
4
VARIETY OF LIFE
5
THE KINGDOM PROKARYOTAE
6
KINFDOM POTOCTISTA
7
KINFDOM FUNGI
8
KINGDOM PLANTAE
9
KINGDOM ANIMALIA
10
BIOENERGETICS
11
NUTRITION
12
GASEOUS EXCHANGE
13
TRANSPORT
14
 CHAPTER 1: THE BIOLOGY

BIOLOGY:
"Biology is the branch of science that deals with organisms and different phenomenon
Of life."
Formerly the living organisms were classified into two kingdoms i.e. Plant kingdom and Animal
kingdom.
*Plants were studied under the subdivision BOTANY.
*Animals were studied under the subdivision ZOOLOGY.

MAJOR BRANCHES OF BIOLOGY:

FIELDS OF SPECIALIZATION IN BIOLOGY:

Modern biology does not only concern with the recognition and classification of these species
but also deals with their vital structural and functional aspects. This has led to the division of
biology into a large number of extremely specialized branches. Some of the major branches or
fields of specialization in biology are discussed below:

1) MOLECULAR BIOLOGY:
It is a branch of biological science that deals with the structure and function of molecules that
form structure of cell and organelles that take part in the biological processes of a living
organism(nucleic acid ,protein molecules).

2) MICROBIOLOGY:
It deals with the study of microorganisms that can only be seen with the help of an optical aid
i.e. microscope.

3) ENVIRONMENTAL BIOLOGY:
It deals with the study of environment and its effects on organism.

4) MARINE BIOLOGY:
It deals with the study of organisms inhabiting the sea and ocean and the physical and the
chemical characteristics of their environment.

5) FRESH WATER BIOLOGY:

It deals with the life dwelling in fresh waters, physical and chemical characteristics of fresh
water bodies effecting it.

6) PARASITOLOGY:
It deals with the study of parasitic organisms, their life cycles, mode of transmission and
interaction with their host

7) HUMAN BIOLOGY:
 This branch of biology deals with all biological aspects of man regarding evolution,
anatomy, physiology, health, inheritance etc.

8) SOCIAL BIOLOGY:
Social biology is concerned with the social interaction within a population of a given animal
species, especially in human beings focuses on such issues as whether certain behavior are
inherited or culturally induced.

9) BIOTECHNOLOGY:
It deals with the use of data and techniques of engineering and technology for the study and
solution of problems concerning living organisms particularly the human beings.

LEVELS OF BIOLOGICAL ORGANIZATION:

All living organisms show diversity in their structural and functional organization, which means
that they have been changed time to time from simplest form to the more complex form.
This complexity and organization is composed of different levels which are arranged on one
another from bottom to the top as show in the flow chart:

 FOUNDATION OF LIVING ORGANISMS:

Sub Atomic
Particles Cell Population

Atom Community
Tissue

Molecule Organ Ecosystem

Organic Molecules Biosphere

Organ System
(Macromolecule)

Living Organism
Organelles Specie

 The foundation of living organisms is based on elements.

1. ELEMENT:
It is the smallest particle of matter, which take part in chemical reaction.
2. ATOM:
The smallest unit of an element, which retains all properties of an element, is called
atom.
3. MOLECULE:
 When atoms combine in specific way, they form molecule.

 Formation of simple and complex molecule:

 Simple Molecule: It is formed spontaneously e.g. CO2
 Compound Molecule: Living matter within the bodies of living organisms
forms this molecule.
Building block of living matter:The building block of living matter is carbons which
form the organic molecule.
Complex Molecule: Complex molecule of different element comprises a
compound. These are of two type i.e. organic compounds and inorganic compounds.
Simple Organic Compound: It includes Glucose, glycerides, fatty acids, amino acids.
The simple organic compounds are arranged into carbohydrates, proteins, fats etc.

Inorganic Compound: It includes H2O, minerals and salts etc.

Origin of Cells:
The arrangement and formation of complex molecules leads to the formation of cell.

1. Cell:
A cell is the smallest, structural and functional unit of living body. Cells are made up of
protoplasm which consist of two parts i.e. cytoplasm and nucleoplasm. Cytoplasm
contains cellular organelles where as a nucleoplasm consist of DNA, RNA and proteins.
The DNA is a hereditary material, which contains coded information.

 Unicellular Organisms:
Those organisms which consist of one cell are called unicellular organisms.
 Multicellular Organisms:
The body of Multicellular organisms consists of more than one cell.
2. Tissue:
A group of cells which have similar structure and perform similar function is called
tissue e.g. Epithelial tissue, Nervous tissue etc.
3. Organs:
Different tissues combine together to form organs e.g. Brain Kidney etc.
4. Organs System:
Several organs that collectively perform a single function produce an organ system e.g.
Brain, spinal cord, sense organs and nerves form the nervous system.
5. Organism:
All system of the body, which works in coordination form a body.
6. Specie:
A group of very similar interbreeding organisms constitute specie.
7. Population:
Member of the same species living in close association in a given area are considered a
population.
8. Community:
Populations of several species living and interacting in the same area form a
community.
9. Ecosystem:
The interaction between living and non living things of an environment forms an
ecosystem.
10. Biosphere:
 It is a part of earth where living organisms are inhabitant by non-living components.

PHYLETIC LINEAGE:
“It is unbroken series of species arranged in ancestor to descendant sequence with rest of the
Groups evolved from one that immediately preceded it”
If all the missing links become available then we could know exactly about the origin of life
itself.

BIOLOGICAL METHODS:
The methods of biological study follow the same principle as adopted in other branches of
science. Scientific information is derived from definite observation, data and experiments.
Biological method follow the steps given below:

OBSERVATION:
Most of the biological investigation start with an observation. After selecting, certain biological
problem, observations are made to collect relevant information.

HYPOTHESIS:
On the basis of observation, scientist formulates a tentative statement called hypothesis
In the light of observed facts and previously collected information, biologist make intelligent
guess as to what maybe the possible answer to this particular question. This intelligent guess in
a form of a statement is called hypothesis.
The hypothesis is a statement made by scientists about a certain phenomenon, on the basis of
available information.

REASONING:

Deductive Reasoning:
Deduction is reasoning from the general to the specific “Deductive logic” of “if - then” is
frequently used to frame testable hypothesis.
Inductive Reasoning:
The other way of reasoning used in the formulation of hypothesis is “inductive generalization”,
which is reasoning from the specific to the general

EXPERIMENT:
The next step is to EXPERIMENT each deduction practically to find out whether or not the
hypothesis is correct. In testing the deduction we are actually testing a hypothesis.

THEORY:
When the hypothesis is supported by a large amount of different types of observations and
experiments, then it becomes a theory.
Theory is a set of scientific assumptions consistent with one another and supported by evidence,
but not fully proved. eg theory of evolution.

SCIENTIFIC LAW:
A theory which is tested again and again and found to fit the facts and from which valid
predictions may be made is then known as scientific law.

APPLICATION OF BIOLOGY FOR THE WELFARE OF MANKIND:

Knowledge of biology ensures a higher standard of living. It helps people to participate
intelligently in programs designed to promote better health, protection and conservation of
environment, application of modern techniques in the field of agriculture and medical
sciences etc.

 IN THE FIELD OF MEDICINE:

1. VACCINATION:
It was first introduced by EDWARD JENNER in 1795.In vaccination process, vaccines are
introduced in animals and man to prevent them from many infectious diseases such as polio,
small pox, hepatitis etc.

2. ANTIBIOTIC:
Definition:
Antibiotics are substances which in low concentration inhibit the growth of microorganisms.
Discovery:
The first antibiotic to be discovered was PENICILLIN. It was derived from fungus PENICILLIUM
NOTATUM. The credit for the discovery, isolation and large scale production goes to FLEMING,
FLOREY and CHAIN. Due to these antibiotics many critical diseases of past like T.B, leprosy and
anthrax etc. have been controlled successfully.

3. CHEMOTHERAPY:
With the advancement of medical sciences; biologists have, and still are, busy developing
health. These days chemotherapy of certain previously uncured diseases like cancer and AIDS
etc has proved to be successful.

4. RADIOTHERAPY :
Discovery of radioactive rays and X-rays is also a great achievement of biological research has
been used in medicinal sciences for the diagnosis and treatment of human diseases. Recent
medical technology of treating cancers and tumors by radiotherapy has been successfully
introduced.

 PROTECTION AND CONSERVATION OF ENVIRONMENT:

Biology helped mankind in attracting attention to this problem and the biologist are striving to
find the solution to set this environment right wherever it has deteriorated.
 Industrial Waste’s Treatment:
Biologists have already asked for the treatment of industrial effluent to be made obligating.
 Biological Control:
Several ways of bioremediation are also under investigation. For example
 Algae have been found to reduce pollution of heavy metal by bioabsorption.

 Introduction of small fishes in ponds to eradicate pathogen like mosquitoes.

 Conservation of Wildlife:
The biologist have worked out the list of endangered species of various animals and stressed
the needs for their protection, which if not protected would soon be extinct.

 F00D AND NUTRITION:

A constant problem of mankind has always been to get food. With the increase in human
population this problem has become worse. Biologists has been trying their best to tackle this
problem by developing effective techniques to be introduced in agricultural field to produce
better quality crops.
  HYDROPONICS :
Introduction:
It is a science of growing terrestrial plants in an aerated solution. It is also known as soil less or
water culture.
Explanation:
Hydroponic farming of vegetables and other essential plants is one of the techniques through
which plantation in certain parts of the world has fulfilled the food requirement of inhabitants
.Hydroponics was developed to conduct experiments on the nutrient requirement of plant
especially the micronutrients.
Advantages:
The advantages of hydroponic farming are as follows:
i) Weed and Soil Disease:
It controls weed and soil disease problem.
ii) Area Requirement:
Area required for cultivation is reduced.
iii) Food Production:
Crops are successfully grown in arid parts of the world to meet the food requirements of
those areas.

 CLONING:
Definition:
Cloning is defined as the production of duplicate copies of genetic material, either cells or
entire multicellular living organism. The copies are referred to as "clones"
Examples:
*Identical twins or triplets in humans
*asexual reproduction in plants and animals
*regeneration
*development of tumors and cancers
Advancements:
*The possibility that people might be cloned from the cells of a single adult human being had
long been under study. Biologists have successfully cloned lower mammals
*Recently, Dolly the sheep was a highly successful clone from a somatic cell, reported back in
1997.This lead scientist to take a step forward to clone humans.
Procedure:
In the process of cloning the nucleus of a fertilized egg is removed. Then a nucleus from a cell
of fully developed individual is taken and introduced into that zygote. After that this changed
zygote is implanted into the womb of female for complete development. The individual which
is developed by this process is quite similar to that individual whose nucleus is used.
Advantages:
*cloning of human cells such as liver cells, skin cells and blood cells have been very promising
and scientists are quite hopeful to develop human organs in the laboratory by artificial cloning
*There are enormous advantages of artificial cloning in areas such as agriculture and
medicine. Vegetative production of various fruits and nuts by grafting is one of the best
examples
*A major goal of this technique is to use it for treating diseases
*Through this technology, production of medically significant substances such as insulin,
growth hormones, interferon and ant thrombin have been achieved.
Disadvantages:
*These plants are sterile; do not reproduce by sexual method.
*This technique may cause change in the structure or number of chromosomes.

CHAPTER 2:BIOLOGICAL MOLECULES

INTRODUCTION TO BIOCHEMISTRY:
The branch of biology that explains the biochemical basis of life is called biochemistry.

IMPORTANCE:
*Biochemistry is very important branch of biological science as it provides information about
all processes carried down in the living organisms
*It also provides information about abnormal mechanism which leads to diseases, ultimately
goes to development of medicine and medical equipment to elucidate these abnormalities.
*Recent biochemical concepts, powerful techniques enabled us to investigate and
understand some most challenging and fundamental problems in biology and medicine e.g.
how does a fertilized egg give rise to different types of cells such as muscle, brain and liver
etc. How do cells find each other to form a complex organ?

PHYSICO-CHEMICAL PROPERTIES OF PROTOPLASM:

Semi-transparent and slightly viscous fluid Protoplasm is a colorless

Composition:
*It is much complex in chemical composition.
*It forms many living structures in the cell & they are called protoplast
*It contains 75% to 80% water together with solids that are mostly proteins.
*Other contents are salts, carbohydrates, ions and many other soluble and insoluble ionic &
molecular substances.

Nature:
Although the protoplasm is generally of fluid nature, it is elastic and can be stretched into
long threads, which snap back when released.
Viscosity of protoplasm is changeable because sometimes it behaves like a semi stiff solid or
gel.

Effect of heat and cold:

(1)Protoplasm coagulates into a dead mass at temperature above 60o C.
(2) When it is allowed to cool, it solidifies into a semisolid, the gel.

Movement of Protoplasm::
(1)The living protoplasm exhibits active streaming movement.
(2) It moves on like a stream around the inner surface of the cell. This movement is usually in
a circle and known as cyclosis.
(3) The protoplasm is responsible for the movements of plastids and other granules along
with it

SIGNIFICANCE:
(1)Protoplasm is the essential part of all living cells.
(2) It is the seat of all vital activities of the organism and hence rightly described as the
"Physical basis of life" by Huxley.
 (3)The various phenomenon of life are due to the characteristics of protoplasm

CHEMICAL COMPOSITION OF PROTOPLASM:

Protoplasm is the mixture of many kinds of substances. These substances can be generally
classified as;

INORGANIC COMPOUNDS:
They include water and minerals

ORGANIC COMPOUNDS:
Organic compounds of a cell are called biomolecules.
*Protein
*Lipids
*carbohydrates
*Nucleic acid
*Conjugated molecules.

WATER:
-A typical cell contains 70-80% of water; therefore it is the most abundant component of
protoplasm.
-Water in the cell occurs in two forms i.e. free and bound.
-Free water is that which is available for metabolic process, whereas bound water is loosely
held by protein molecules.

CHEMISTRY OF WATER:
* The chemical formula of water is H2O, which indicates that two atoms of hydrogen are
joined to one atom of oxygen to make up each water molecule
*"Water is a polar molecule”; it means that it has a very slightly positive end-the hydrogen
atoms and a very slightly negative end-the oxygen atom. This separation of electric charge is
called dipole, which gives the water molecule it’s very important properties.
*One of the most important result of this charge separation is the tendency of H 2O molecule
to form HYDROGEN BOND.

BIOLOGICAL IMPORTANCE OF WATER:

The Holy Quran says that every living organism is made up of water, so water is highly
important substance for life. Some important properties of water are given below:

1. SOLVENT NATURE:
Due to polarity of water molecules, many polar substances (solute), particularly ionic
substances dissociate in ions and dissolve in H2O.Water can also act as a solvent to many
non-polar substances. As all the chemical reactions that go on within the cell takes place in
aqueous solution, the ability of water to act as a solvent is vitally important for the process of
life. Ions or molecules, which are dissolved in water more & collide to perform chemical
reactions.

2. HIGH SPECIFIC HEAT:

The specific heat of a substance is a measure of amount of energy needed to raise the
temperature of a unit mass of that substance by 1o C.
The specific heat capacity of water is high; it takes a lot of energy to warm it up. This
 biochemistry of life carried at fairly constant rate.

3. HIGH HEAT OF VAPOURIZATION:

Due to hydrogen bonding which holds the water molecules together, liquid state of water
requires higher amount of heat energy to change into vapours. It also gives stability to water
molecules. Therefore water needs to lose a lot of energy to form ice, due to this reason the
content of cell are unlikely to freeze.

4. AMPHOTERIC NATURE OF WATER MOLECULES:

The water molecules is amphoteric i.e. it acts both as an acid and a base. As an acid, it gives
up electrons to form H+ ion. As a base, it gains electrons to form OH- ions.

5. BUFFER ACTION:
Water acts as a buffer. A buffer helps to prevent changes in the pH of a solution when an acid
or an alkali is added. Thus the water in cells minimizes any change in the pH, which prevents
any interference in the metabolism of the cell.

6. COHESIVE FORCE IN WATER MOLECULES:

Water molecules tend to remain together because of hydrogen bonding. It helps it to flow
easily. Water molecules also adhere to surface therefore it can fill a tubular vessel and still
flow so that dissolved and suspended molecules are evenly distributed throughout a system.
Therefore water is an excellent transport and matrix medium both outside & inside the cell

PROTEINS :(Greek; Proteios means "First Rank")

DEFINITION:
"A long chain organic molecule which is made of many smaller molecules of Amino acids
linked together by covalent bonds is called protein."

DISCOVERY:
The name protein was suggested by Berzelius in 1838 and the Dutch Chemist G.J Murlder in
1883 recognized the importance of protein as a vital compound.

GENERAL CHARACTERISTICS:
1) Proteins are the most important organic compound of the cell which carry out virtually all
of the cell activities
2) They constitute more than 50% of dry weight of cell
3) Proteins are the complex organic compounds having C, H, O and N as elements but
sometimes they contain P and S also.
4) Due to the presence of N they are called nitrogenous compounds.
5) Proteins are the building blocks of the tissues.
6) Many common parts of the living body such as hair, skin, nails and feathers are also
proteins

SOURCES OF PROTEIN:
Egg, meat, fish, milk and pulses are the major sources of protein.

CHEMISTRY OF PROTEIN:
There are many types of proteins but all protein molecules comprises of amino acids which
are linked together by a special type of covalent bond called peptide bond.

AMINO ACIDS:
1. Proteins are macromolecules or polymers of amino acid monomers.
2. These amino acids are linked together by specialized bond called 'Peptide Linkage'.
3. Each protein has a unique sequence of amino acids that gives the unique properties to
molecules.
4. Many of the chemical properties of a protein are based upon chemical properties of its
constituent’s amino acids.
5. There are 20 basic amino acids which are commonly found in proteins of the living
organisms ranging from virus to human being.
6. Amino acids are organic compounds which contain at least one basic amino group (-NH2)
and the acidic carboxylic group (-COOH) bounded to the same carbon atom called x-carbon
having following general structural formula.

PEPTIDE LINKAGE:
1. During the process of proteinsynthesis; each amino acid becomes joined to two other
amino acids forming a long continuous, unbranched polymer called polypeptide chain.
2. In polypeptide chain there amino acids are linked together by condensation process.
3. The proteins are polypeptides with usually more than 100 amino acids but some proteins
are small in size having less number of amino acids.
4. The sequence of amino acids in the peptide chain is specific for each protein and
potentially capable of great diversity.

STRUCTURE OF PROTEIN:
There are four basic structural levels of proteins

PRIMARY STRUCTURE:
A polypeptide chain having linear sequence of amino acids is called primary structure.
Disulphide (S-S) bond is other important characteristic of primary protein.

SECONDARY STRUCTURE:
When a polypeptide chain of amino acids becomes spirally coiled this structure is called
secondary structure of protein. It results in the formation of rigid and tubular structure called
helix.
TERTIARY STRUCTURE:
The term tertiary structure refers to the arrangement of secondary structure into 3
dimensional (folds or super fold) structure.

QUATERNARY STRUCTURE:
It is the association of 2 or more sub units (polypeptide chains) into large sized molecules
called quaternary structure e.g. Haemoglobin. In quaternary structure the participating units
may be similar or dissimilar, if they have similar unit called homogenous quaternary structure
and if dissimilar called heterogenous quaternary structure.

FUNCTIONS OF PROTEINS:
Proteins have wide variety of structure therefore they perform variable functions some of
which are given below:

 STRUCTURAL FUNCTIONS:
All organisms are made of proteins so protein is the building material of life.it is estimated
that the typical mammalian cell may have as 10,000 different proteins having a diverse array
of function. As structural cables protein provide mechanical support both within cell and
outside their perimeter.

 ENZYMATIC FUNCTIONS:
Enzymes are biological catalysts which accelerate the rates of biochemical reactions in all
living organisms. All enzymes are protein in nature. Therefore as enzymes proteins vastly
accelerate the rate of metabolic reactions.

 REGULATORY FUNCTIONS:
As hormones, growth factors & gene activators, proteins perform a wide variety of regulatory
functions. As membrane receptor & transporters protein determine what type of substances
should enter or leave the cell.

 IMMUNITY:
Natural defence mechanism of higher organisms against microorganisms, parasites etc is
called immunity. This is accompanied by antibodies, which are protein in nature.

 TRANSPORTATION: Some protein molecules carry oxygen, nutrients and other

substances to the body tissue with the circulation of blood.

CARBOHYDRATES:
INTRODUCTION:
It is a group of organic compounds containing carbon, oxygen and hydrogen in which
hydrogen and oxygen are mostly found in the
same ratio as in H2O i.e. 2:1 and thus called hydrated carbons.

DEFINITION:
"Carbohydrates can be defined as polyhydric alcohols which contains potentially active
aldehyde or ketone functional group"
Carbohydrates are found to occur in all living cells as both building material & as storage
substances. They are found about 1% by weight & generally called sugar or saccharides due
to their sweet taste except polysaccharide
CLASSIFICATION:
The carbohydrate can be classified into following groups on the basis of number of
monomers.
These are:
* Monosaccharaides
* Polysaccharides
* Oligosaccharides

 MONOSACCHARAIDES:
These are also called simple sugars because they cannot be hydrolysed further into simpler
sugars
Monosaccharaides are found in various fruits and vegetables most of them are found in
combined state e.g.:
GLUCOSE: Found in ripe fruit , sweet corns and honey. On the other hand it is also found in
starch, sweet corn. In sugar cane it is associated with fructose.
FRUCTOSE: Most abundant hexose found in nature generally called "fruit sugar"
GALACTOSE: Is found largely in combined state in lactose (milk disaccharide)

 OLIGOSACCHARIDES:
The carbohydrate molecule which yield 2-10 monosaccharide molecules on hydrolysis are
oligosaccharides. The most abundant & common carbohydrates of oligosaccharide are
disaccharides

Following are some examples of disaccharide molecules:

SUCROSE
It is found in most plants. It is stored in large amount in sugar cane & beetroot.
Glucose + Fructose  Sucrose + H2O
LACTOSE:
It is found solely in milk
Glucose + Galactose Lactose + H2O
MALTOSE:
It does not occur abundantly in nature. It can be extracted from malt, which is prepared from
sprouting barley
Glucose + Glucose  Maltose + H2O

 POLYSACCHARIDES:
They are formed by high molecular weight carbohydrates which on hydrolysis yield mainly
monosaccharaides or products related to hundreds or thousands of monosaccharide they are
formed by the condensation of hundreds or thousands of monosaccharide units e.g. Starch,
Glycogen & Cellulose.

STARCH:
It is the most important reserve food material of higher plants, found in cereals, legumes,
potatoes and other vegetables. It is made up of many glucose molecules joined together in
straight chain, amylose and a branched chain amylopectin. It is insoluble in H2O.Starch is
converted into simple sugar by hydrolysis & then oxidized to produce energy to be used in
metabolism of other biomolecules.
 CELLULOSE:
Cellulose is a glucose polymer produced by plants. The glucose units are joined in straight
chain & no branching in the cellulose molecule is indicated. It is the main constituent of plant
cell wall & moat abundant carbohydrate in nature

GLYCOGEN:
It is also a reserve polysaccharide found mainly in bacteria, fungi, liver and muscle tissues of
animal. It is also commonly known as animal starch. It is insoluble in water & stored in
granular form

FUNCTIONS OF CARBOHYDRATES:
i. AS A SOURCE OF ENERGY:
Carbohydrates are the potential source of energy. This energy is utilized in body metabolism.
Carbohydrates also act as storage food molecules. In plants excess glucose is converted into
starch & in animals into glycogen

ii. STRUCTURAL FUNCTION:

Carbohydrates also work as an excellent building, protective & supporting structure e.g.
*Cellulose is the major component of cell wall.
*In animals chitin forms the exoskeleton of arthropods.

iii. CONJUGATED MOLECULES:

They also form complex conjugated molecules

iv. PART OF BALANCED DIET:

Carbohydrates is the major part of the balanced diet of humans

v. ACT AS SWEETENERS:
Some monosaccharaides & disaccharides also act as sweeteners e.g. Glucose, fructose &
sucrose etc.

vi. COMPONENT OF CHROMOSOMES:

Deoxyribose is an important monosaccharide as it is an essential part of chromosome of all
iving organisms.

LIPIDS:
Lipids & fats also the organic compounds of carbon, hydrogen & oxygen. The relative amount
of oxygen is much less than that in carbohydrate
Bloor in 1943 proposed the term lipid for those naturally occurring compounds, which are
insoluble in H2O but soluble in a special organic solvent called Bloor's reagent. It consists of
diethyl ether & ethyl alcohol.

CLASSIFICATION:
Lipids can be classified as follows:
1. Acylglycerol (fats & oil)
2. Waxes
3. Phospholipids
4. Terpenoids
 1) ACYLGLCEROL:
*They are found both in animal & plant.
*They provide energy for different metabolic activities & are very rich in chemical energy.
*It is estimated that a person of average size contains approximately 16 kg of fat which is
equivalent to 144000 Kcal of energy which takes a very long time to deplete.
*Acylglycerol consists of a glycerol molecule linked to 3 fatty acids. This condensed molecule
is called a triacylglyceral (Triglyceride).

There are 2 type of acylglycerol:

SATURATED ACYLGLYCEROL:
They contain saturated fatty acids i.e: they do not contain any double bond between carbon
atom. They are solid at ordinary temperature, mostly found in animals.
E.g. Stearin (C57H110O6) found in beef and mutton

UNSATURATED ACYLGLYCEROL:
They contain unsaturated fatty acids i_e they contain one or more than one double bond
between carbon atom (-C=C-).They are liquid at ordinary temperature. They are found in
plant also called oil
E.g. Linolin found in cotton seed contains linoleic acid.

2) WAXES:
*Waxes are simple lipids having one molecule of fatty acid forming ester bond with one
molecule of long chain alcohol. E.g. Bee's wax.
*Waxes are found as protective covering on stem, stalks, leaves, petals, fruit, skin, fur,
feather etc.
*Waxes are water repellant & non-reactive.
*They are of considerable commercial importance because they act as superior machine
lubricants.

3) PHOSPHOLIPIDS:
*It is the most important class of lipids from biological point of view.
*It is similar to triacylglycerol or oil except that one fatty acid is replaced by phosphate group.
*The phospholipid molecule consist of 2 ends which are called hydrophilic (water loving) end
(head) & hydrophobic (water fearing ) end ( tail ).
*Phospholipids are present in all living cells frequently associated with membranes & are
related to vital function such as regulation of cell permeability & transport processes.
*Properties of cell membrane depend on their phospholipid component.

4) TERPENOIDS:
Terpenoid is an important & large class of lipids, built up of isoprenoid (C5H8) units. Steroids,
carotenoids & terpenes are the important classes of it:

CHARACTERISTICS:
*They help in oxidation & reduction process as terpenes
*Some are components of essential oils of plants e.g. menthol, camphor, mint etc.
*They also found in cell membrane as cholesterol
*Plant pigment like carotene, xanthophyll are also the form of terpenoids.
TERPENES:
*This group of lipids is based on isoprenoid unit.
*Small sized terpenes are volatile in nature & produce special fragrance.
*some of these are use in perfumes e.g.
 Myrcene from oil of bay Geranoil from rose
 Limonene from lemon oil  Menthol from peppermint oil
*Derivatives of some terpenes are found in Vitamin A
*They are also important constituents of chlorophyll molecules as well as intermediate
compound for cholesterol biosynthesis.
*In nature they are utilized in the synthesis of rubber & latex.

STEROIDS:
*Steroids consist of three 6-carbon rings (A, B, C) & one 5(D) carbon ring
*These rings are fused together as shown below with total 17-C atoms called steroid nucleus
Examples: Most important steroid is cholesterol, a component of animal cell membrane & a
precursor for the synthesis of a no. of steroids, sex hormones such as testosterone,
progesterone & estrogen.

CAROTENOIDS:
Carotenoids consist of fatty acid like carbon chain which are conjugated by double bonds &
carrying 6-membered carbon ring at each end.
* These compounds are pigments producing red, orange, yellow, cream & brown colours in
plants
*some important carotenoids are:
1. Carotene
2. Xanthophyll

NUCLEIC ACID:
Nucleic acids are long chain molecules which are made up of small unit molecules called
Nucleotide.

DISCOVERY:
A 22 year old Swiss physician & chemist, Friedrich Miescher isolated a substance from the
nuclei of pus cells which was quite different from other biomolecules & named it as nuclein.
Later, it was found that the nuclein had acidic properties & hence it was renamed as nucleic
acid.

GENERAL CHARACTERISTICS:
*Nucleic acid is present in all living organisms, from virus to human
*These macromolecules are present either in the free state or bound to proteins as
"nucleoproteins"
*Like proteins, the nucleic acid are biopolymers of high molecular weight with
mononucleotide as their sub units (monomers).
*The nucleic acids are the long chains of polynucleotide in which mononucleotide are linked
with each other.

CHEMISTRY OF NUCLEIC ACID:

There are two kinds of nucleic acids
1. Deoxyribonucleic acid (DNA)
2. Ribonucleic acid (RNA)

*DNA is found mainly in the chromatin of all nucleus whereas most of the RNA (90%) is
present in the cell cytoplasm & a little (10%) in the nucleolus
*Nucleic acid is a polymer of nucleotide

NUCLEOTIDE:
Nucleotide is a molecule which consist of following 3 parts
1. Pentose sugar (5-C)
2. Phosphoric acid (H3PO4)
3. A nitrogenous base

Pentose sugar: Found in nucleotide is either Ribose (C5H10O5) OR deooxyribose.

(C5H10O4).Ribose is found in RNA while deooxyribose in DNA
Phosphoric acid: Is common in all nucleotides. It is attached with 5th carbon of pentose sugar
in each nucleotide
Nitrogenous base: Are of two types i.e. Purine & pyrimidine.
PURINE: Includes 2 nitrogenous bases named Adenine (A) and Guanine (G).
PYRIMIDINE: Includes 3 nitrogenous bases Cytosine, (C) thymine (T), and Uracil (U).

CLASSIFICATION OF NUCLEIC ACID:

Nucleic acids are classified on the basis of the no. of nucleotides in their chemical
composition. There are 3 major types of nucleotides

1) MONONUCLEOTIDE:
A nucleic acid comprising one nucleotide molecule is called mononucleotide.

CHARACTERISTICS:
*Mononucleotides exist singly in the cell or as a part of other molecules
*These are not the part of DNA or RNA.
Some of these have extra phosphate groups. E.g. ATP.
ATP:
*It is an unstable molecule & carries energy from place to place within
a cell.
*ATP consists of Adenosine (Adenine & Ribose sugar) & 3 phosphate groups among them 2
have energy rich phosphate bond.
*During conversion of ATP into ADP, large amount of energy is released (7.3 Kcal/mole)
which is utilized in the formation of proteins, lipids, carbohydrates etc.

2) DINUCLEOTIDE:
A nucleic acid molecule which is formed by the chemical combination of two nucleotides are
referred to as dinucleotide.
NAD:
*Nicotinamide adenine dinucleotide (NAD).
*Nicotinamide is a vitamin constituent. The two nucleotides are linked by phosphate of one
another.
*It carries electron & work with dehydrogenase enzyme.
*It removes 2 hydrogen atoms from its substrate. (2H++2e-)
*Both electrons & one hydrogen ion are passed to NAD which reduces it to NADH.

3) POLYNUCLEOTIDE:
It is a long chain nucleic acid molecule that consists of large no. of nucleotide

BIOLOGICALLY IMPORTANT CHARACTERS:

*They have a variety of role in living organisms

*They serve as repositories (store house & transmitters) of genetic information
*They make it possible for cells to function according to specific patterns & give rise to new
cells with either similar or new function.
*Genetic information is encoded in a nucleic acid molecule in a particular & simple fashion.
*Four different nucleotides make up each other informational nucleic acid molecules.
*The cell interprets the information present in many nucleic acid molecules as sequence of
amino acid in protein & peptide molecules

TYPE OF POLYNUCLEOTIDE:
These are two major types of polynucleotides:
*Deoxyribonucleic acid (DNA)
*Ribonucleic acid (RNA)

DNA-AS A HEREDITARY MATERIAL:

DISCOVERY:
GRIFFITH: Discovered that living bacteria can acquire genetic material from dead bacteria &
transform live bacteria from non-virulent to virulent.
AVERY: And his colleagues showed that the genes taken up living bacteria during
transformation were composed of DNA.
HERSHEY & CHASE: Confirmed experimentally that DNA must be the genetic material.

DNA BEHAVES AS GENETIC MATERIAL:

*DNA is a polynucleotide chain in which nucleotides are arranged in a specific manner.
*In all nucleotides of DNA, phosphates and deooxyribose sugars are always common but the
nitrogenous bases are different. In other words, we can say that each DNA has specific
sequences of nitrogenous bases.
*These sequences of bases in DNA can encode vast amount of information.
*Since the nitrogenous bases are of four types it is amazing that how just four different types
of bases in DNA encode all of the information needed to produce thousands of proteins each
with various combination of 20 amino acids.
*The four different types of bases can be arranged in any linear order along a strand of DNA.
*Each sequence of bases represents a unique set of genetic instructions e.g. a piece of DNA
with 10 nucleotides can exist in over a million different possible sequences of four bases.
*An average chromosome of plant & animal has millions to billions of nucleotides and DNA
molecule thus encodes a huge amount of information in the form of genetic codes.

RNA-AS A CARRIER OF INFORMATION:

In eukaryotic cells, DNA is located in the nucleus while most of the synthesis and metabolic
functions occur in the cytoplasm under the instruction of DNA.
Therefore DNA requires some intermediate molecules that carry information from DNA to
the cytoplasm. These molecules are ribonucleic acids or RNA's

FLOW OF GENETIC INFORMATION:

Genetic information flows in a cell from DNA to mRNA then to cytoplasm in a two-step
process for the synthesis of protein

1. TRANSCRIPTION:
In this step information contained in a specific segment of DNA is copied into RNA .The RNA
which performs this process is called messenger RNA (mRNA).It carries information from the
nucleus to the ribosomes

2. TRANSLATION:
In this step 2 other types of RNA, transfer RNA (tRNA) and ribosomal RNA (rRNA) translate
the information of messenger RNA (mRNA) into the specific sequence of amino acids which
help to synthesize the
protein.

CONJUGATED MOLECULES:
Conjugated molecules are formed when biomolecules of two different groups combine with
each other acting as unit molecule. When a molecule of carbohydrate combines with protein
molecules, they form glycoprotein. Following are the types of glycolprotein:

1. Glycolipids or cerebrosides:
 These are conjugate of lipids and carbohydrates also contain some
nitrogenous compounds.
 It is important constituent of brain.
 Sulpholipids are also example of glycolipids found in chloroplast.

2. Glycoproteins or mucoids:
 It is formed when carbohydrate molecule combine with a protein molecule
 Most of the oligo and polysaccharides in the animals and plants cells are linked
covalently to protein molecule.
 It contains small amount of carbohydrates i.e. less than 4% e.g. egg albumin,
gonadotropic hormone.

3. Nucleoprotein:
 These are found in the nucleus conjugated with nucleic acid. On hydrolysis
nucleoprotein give rise to simple proteins and nucleic acids.
 These are weakly acidic and soluble in water.

4. Lipoprotein:
 They are conjugates of lipids and proteins
CHAPTER 3: THE ENZYMES
Introduction:
The word enzyme was coined by Friedrich Wilhelm Kuhne in 1878, for the active ingredient
in the juice that promotes fermentation. Enzymes literally means "in yeast" ,but it is now
used as the collective name for the many 100s of compounds that have since been
extracted from cells & shown to have catalytic action on specific reactions.

Definition:
"Enzymes are defined as the organic catalysts which speed up chemical reactions in
organisms"

CHARACTERISTICS OF ENZYME:-

Enzymes possess the following important characteristics:

 Generally enzymes are large, globular proteinous structures with high

molecular weight.
 They increase the rate of reaction without themselves being used up.
 Enzymes are used only in small amount in the chemical process.
 Specific enzyme act on a specific substrate.
 Enzyme lowers the activation energy of reaction.
 Their activity can be accelerated by creation ions or salt called activator.
Such as Ni, Mg, Cl etc.
 The activity of enzymes can be affected by pH, temperature and substrate
concentration.
 The size of enzyme larger than substrate molecules.
 Enzymes are thermolabile and pH dependent

ACTIVATION ENERGY:-
Definition:-

“The minimum amount of energy required to activate and accomplish the biochemical reaction is
known as Activation Energy.”

Enzyme increase the rate of chemical reaction by decreasing the amount of energy required to form
a complex of reactants that is competent to produce reaction product. Enzyme accelerate reactions
by lowering the activation energy.

Mode of Action:
Action of an enzyme is linked to its structure which is complex & 3 dimensional. Each
enzyme has a groove of a specific shape called the active site in to which substrate can fit.

THEORIES ABOUT ENZYMATIC ACTION

There are two well known theories about the mode of action of enzyme. They are as follow:
1. Key-Lock Theory
2. Induce-Fit Model

KEY LOCK THEORY:

In order to explain the mode of action of enzyme, Fischer (1898) proposed a Key lock theory
which was later improved by Paul Filder and D.D Woods.

*They proposed that a particular enzyme acts on a particular substrate like particular lock
can be unlocked by a particular key

Explanation
*This theory depends upon physical contact between substrate and enzyme molecules
*The active site of each enzyme has distinct shape & distribution of charge, which is
complementary to its substrates like lock & key where a lock allow a few complementary
molecules to fit & react while rejecting even fairly similar molecules
*On the other hand some molecules may be able to fit in the active site of an enzyme but do
not have chemical bond upon which the enzyme can act so no reaction occurs
Diagramatic Representation:

INDUCE FIT MODEL:

Koshland (1959) proposed Induce Fit Model .He stated that, when a substrate combines
with an enzyme it induces changes in the enzyme structure enabling the enzyme to perform
its catalytic activity more effectively.
Diagramatic Representation:

CLASSIFICATION OF ENZYME
Enzymes are classified into following classes on the basis of physiology and biochemical
composition.

Position classification of enzyme

Chemical composition classification of enzyme
A. Position Classification of Enzyme:
1. Intra-cellular enzyme
2. Extra-cellular enzyme

1. INTRA-CELLULAR ENZYME:
Definition:

“The enzymes that are produced inside the cell and perform their enzymatic roles
inside the same cell are called intracellular enzyme. It is also called endoenzyme.”

Example: ATP-ase, NAD, FAD etc.

2. EXTRA-CELLULAR ENZYME:
Definition:
“The enzyme that are produced inside the cell but perform their enzymatic roles out
of cell, inside the organ are called extra-cellular enzyme. It is also called
ectoenzyme.”
Example:
Amylase, Lipases, Tryptase etc.

B. BIOCHEMICAL NATURE & TYPES OF ENZYMES:

Enzymes are generally protein in nature. They may entirely consist of protein or may contain
a non-protein part with protein
*If an enzyme consists only of protein it is called “simple enzyme”.
*If it contains another group with protein called "conjugated enzyme"
CONJUGATED ENZYMES:
Euler (1932) proposed that conjugated enzymes showing complete activity are called
holoenzymes .It contains 2 parts:

*Apo enzyme: This is a protein part of enzyme

*Prosthetic group: This is a non-protein part.

TYPES OF PROSTHETIC GROUPS:

On the basis of nature of prosthetic groups, they can be classified into 2 main types:
*Cofactors
*Coenzymes

COFACTORS:
The inorganic Ions which are attached as prosthetic groups with the holoenzymes are
known as cofactors.

E.g: Role of magnesium, manganese, calcium, potassium on enzymes like phosphatases,

phosphorylase, amidase, peptidase, carboxylases are well known.

COENZYMES:
"The holoenzymes in which prosthetic group in an organic compound that may or may not
contain inorganic ions are known as coenzymes"

*A coenzyme constitutes about 1% portion of the entire enzyme molecule.

*This part of enzyme is more or less easily separable usually heat resistant
*Some coenzymes of oxidation & reduction process are NAD, NADP, FMN, ATP etc.

FACTORS AFFECTING ENZYME ACTIVITY:

Following are the factors which affect the enzyme activity:
1. Concentration of substrate
2. Temperature
3. PH
4. Coenzyme, activators & inhibitors
5. Water
6. Radiation

1. Concentration Of Substrate
The rate of reaction increases with an increase in the concentration of substrate until the
available enzyme becomes saturated with substrate.

Limitations:
*There is no increase in enzymatic activity to a certain high level of substrate concentration.
*At a very high concentration the substrate exerts a retarding effect upon enzyme action.
This may be due to 2 reasons:
(a) Higher quantity of substrate than enzyme
(b) Accumulation of end product in high quantity

*Hence substrate & enzyme concentration are directly proportional upto a certain max.
Velocity after which further increase in substrate conc. has no effect on the rate of reaction
 2. Effect of Temperature:
*Enzymes are sensitive to temperature
*Each enzyme has its optimum temp for its maximum activity, above & below this temp. Its
rate of reaction decreases.
*Most of the enzymes are highly active at about 37oC and all are completely destroyed at
100oC whereas at minimum i.e. 0oC, activity is reduced to minimum but enzymes are not
destroyed.

3. Effect Of pH:
*The activity of enzyme varies considerably with pH.
*There is generally a marked optimum pH for each enzyme.

Example: Pepsin of stomach has an optimum pH of 1.4 and it becomes inactive in neutral or
alkaline solution.

4. Effect Of Water:
Water is necessary for enzyme activity as it influences the rate of enzymatic activity .In
germinating seeds, with the increase in amount of water, to some extent, enzymes become
active & germination proceeds

5. Effect Of Radiation:
Enzymes are generally inactivated rapidly by exposure to ultraviolet light
They are also inactivated by β (beta) rays, ɣ(gamma) rays and x-rays

6. Co-enzymes Activators and Inhibitors:

Enzyme action is frequently accelerated or inhibited by the presence of certain other

substances. These have been divided into 3 categories.

COENZYMES:
If the co factor is an organic molecule, it is called co enzyme. Without co enzyme certain
enzymes are unable to function.
Example:. CoA, NAD and FAD etc. Most vitamins are co enzymes or raw materials from
which co enzymes are made.

ACTIVATORS:
Inorganic substances, which increase the activity of an enzyme are called activators.
Example: Mg ion is an inorganic activator for the enzyme phosphatase and Zn(Zinc) ion is an
activator for an enzyme Carbonic anhydrase.

INHIBITORS:
Substances which decrease the activity of an enzyme are called inhibitors
The inhibitors may act by combining directly with an enzyme or they may react with the
activator directly therefore activator does not remain available to enzyme for activation
There are two types of inhibitors:
TYPE OF INHIBITORS:
There are two types of inhibitors:
1. Irreversible Inhibitors
2. Reversible Inhibitors
1. IRREVERSIBLE INHIBITORS:
The inhibitors which permanently make enzyme unreceptive for the substrate molecules are
called Irreversible Inhibitors.
Example:
Poisons and some antibodies act as an Irreversible Inhibitor.

2. REVERSIBLE INHIBITORS:
Reversible inhibitors are those whose inhibitory effects can be reversed.
Example:
Reversible inhibitors can be divide into following two:
1. Competitive Inhibitor
2. Non-Competitive Inhibitor.

-Competitive Inhibitors:
 Some inhibitors resemble the normal substrate
molecule & compete for admission into the
active site; these are known as competitive
inhibitors.
 They reduce the productivity of enzyme by
blocking the substrate from entering active
site.

-Non-competitive Inhibitor:
 The inhibitors which obstruct enzymatic reactions by binding to a part of enzyme
away from the active site are referred to as non-competitive inhibitors.
 This interaction causes the enzyme molecule to change its shape, rendering the
active site unreceptive to substrate or leaving the enzyme less effective at catalyzing
the conversion of substrate to product.
 In non-competitive inhibitors a molecule binds to the enzyme other than its active
site.
 This other binding site is called allosteric site.

FEEDBACK INHIBITION:
The activity of almost every enzyme in a cell is regulated by feedback inhibition
Feedback is an example of a common biological control mechanism called "negative
feedback."
When the product is in abundance it binds competitively with its enzyme's active site as
the product is used up, inhibition is reduced & more products can be produced.
In this way concentration of the product is always kept within a certain range.
Most enzymatic pathways are always regulated by feedback inhibition, but in these cases
the end product of the pathway binds at an allosteric site on the first enzyme of the
pathway.
This binding shut down pathway & no more product are produced.
 CHAPTER 4: THE CELL
CELL:
Definition:
Cell Cella or Kytos – (hollow space)
“The basic structural and functional unit of life is called Cell.” OR
“The building block of life is called Cell.”
CELL THEORY:
Introduction:-
Cell theory was the first generalized theory, which developed after years of research in the
field of biology.
1. In 1838, Schleiden, a German botanist, described that plants were made up of cells in spite
of the differences in the structure of various tissues.
2. In 1839, a German zoologist T. Schwann described the cellular basis of animals in a
comprehensive report. Both of them proposed a theory which described the function and
working of cells:
POSTULATE OF CELL THEORY:-
 All organisms are composed of one or more cell.
 The cell is the structural unit of life.
3. They also believed that cells can arise “de-novo” or from the non-living material but the
ideas of “de-novo” formation of cells was challenged by Rudolf Virchow, who added
another significant point in the cell theory:
 “Cells can arise only by division of pre-existing cell.”

MICROSCOPE:
Micro means small, Skopean means vision
“Microscope is an instrument, which is used to magnify micro-organisms. According to the
source of light microscopes can be divided, into following types.”

1. LIGHT MICROSCOPE:
The microscope in which visible light is used as source of illumination is called Light
P Microscope.

2. X-RAY MICROSCOPE:
L The microscopes in which short wave length X-rays are used as source of illumination
are called X-ray Microscopes.

3. ELECTRON MICROSCOPE:
A The microscopes in which electron beam is used as a source of illumination are called
Electron Microscopes.

N
T
C
E
A
N
I
M
A
L

C
E
IMPORTANT FEATURES OF MICROSCOPE
L There are 3 main features of a microscope.

1. MAGNIFICATION:

L Magnification is the increase in the apparent size of the object. Magnification of microscope
is calculated by multiplying the magnifying power of its eyepiece with that of its objective.
 A light microscope can magnify an image by 10,000x.
 An electron microscope can magnify an image by 100.000x.

2. RESOLUTION:
Resolution is the capacity to separate adjacent objects from each other.
 The resolving power of light microscope is limited and is about 500 times
better than unaided human eye.
 The resolving power of electron microscopes is 10,000 times better than
unaided human eye.

3. CONTRAST:
 Contrast is the differentiation of two parts of the cells from each other. It may
be obtained by fixing and staining the material.
TECHNIQUES TO ISOLATE COMPONENTS OF CELL:
CELL FRACTIONATION:
Isolation of cellular components, to determine their chemical composition is called cell
fractionation.

PROCEDURE:
1. For cell fractionation, first of all it is necessary to break a large number of similar types
of cells in ice-cold environment.
2. The cells are usually placed in a homogenizer and motor are broken.
3. The freed content of the cells are subjected to a spinning action known as
“Centrifugation”.
4. At a low speed, large particles like cell nuclei are settle down in the sediment.
5. They can be poured into a fresh tube and subjected to centrifugation at a higher speed
until the smaller particles have been separated out.
6. The various cell fractions can then be biochemically analyzed.

STRUCTURE OF EUKARYOTIC CELL:

A typical eukaryotic cell consists of following parts.
1. Plasma membrane
2. Nucleus
3. Cytoplasm and cytoplasmic organelles
4. Cell wall: It is found in plant cell, bacterial cell, fungal cell, but absent in animal cell.

*PLASMA MEMBRANE:
Definition
“A membrane that surrounds a typical cell, separating its cytoplasm from the external
environment is known as cell-membrane or plasma membrane”

It is selectively permeable in nature and allows the cell to take up and retain certain substances
while not allowing others to pass through.

Structure:
 All biological membranes have same basic molecular organization. They consist of a
double layer (bilayer) of phospholipids and proteins.
 The phospholipids molecules in the plasma membrane are arranged in two parallel
layers; having two ends.

A Hydrophobic ends: It is non-polar end.

B. Hydrophilic ends: It is polar end.

 The non-polar hydrophobic ends are present opposite to each other while polar ends
are attached to carbohydrates and proteins.
 Plasma lemma also contains several types of lipids like cholesterol. In certain animal
cells cholesterol may constitute upto 50% of lipids molecules in plasma membrane. It
is absent from the plasma membrane of most plant and bacterial cells.

FLUID MOSAIC MODEL:

 1. In 1972 Singer and Nicholson proposed a working model of cell
membrane called “Fluid Mosaic Model.”
2. It presents the membrane as a lipid bi layer in which, the lipid
molecules are capable of rotating and moving laterally within the
membrane.
3. The structure and arrangement of membrane proteins are explained
as the fluid mosaic or like icebergs in the sea.
4. The protein occurs as a “mosaic” of discontinuous isles that
penetrate completely or incompletely in the lipid sheet.
5. It suggests that the component of plasma membrane are mobile and
are capable of coming together and engage in various types of
transient or semi-permanent interaction.
The proteins associated with the lipid bi layer are of 2 types.

1: EXTRINSIC PROTEIN:
 These proteins are present along the surface
of lipids.
 These are also called peripheral proteins.
 They have loose attachment with the
membrane surface.

2: INTRINSIC PROTEINS:
 These proteins are found deeply in the lipid layers.
 They help in the movement of H2O soluble ions outside or inside the cell.
 The proteins are associated with lipids called lipoproteins or carbohydrates called
glycoproteins.
 The proteins are found like a mosaic within the cell membrane, so the model is
called fluid mosaic model.

FUNCTIONS OF PLASMA MEMBRANE:

1- PROTECTION OF CELL:
Plasma membrane protects the cytoplasm of a cell. It is the most important function.

2- PERMEABILITY:
It is the regulatory function of flow of solutions and materials in and out of cells. The
permeability is basically of two types. i.e. passive and active transport.

a) Passive Transport:
A type of transport that does not require energy is called passive transport. It has further two
types:
Osmosis:
Transport of solvent molecules across a semi-permeable membrane from the medium of
higher solvent concentration to a medium of lower solvent concentration is called osmosis. It
maintains a balance between osmotic pressure of the intracellular fluid and that of interstitial
fluid, is called osmoregulation.

Diffusion:
When two solutions of different concentrations are mixed, the phenomenon is called
diffusion which is defined as the dispersion of molecules from the medium of their higher
concentrations to that of lower concentration. Movement of certain gases e.g: O2 and CO2 in
and out of the cell is well known example.

b) Active Transport:
In this process the molecules more against the concentration gradient, i.e; they move from
the region of lower concentration to the region of higher concentration and this process
requires energy to counteract the force of diffusion. It has two types’ i.e; endocytosis and
exocytosis.

-Endocytosis:
The process in which solid or liquid
material is taken into the cell is
called endocytosis. It is of further two
types.

a. Phagocytosis:
In this process solid particles are
picked and ingested by the cell through
plasma membrane.
e.g: WBCs pick up foreign particles from
the blood stream.

b. Pinocytosis:
It is the uptake of fluid in bulk or the uptake of fluid vesicles by living cell is called pinocytosis.

-Exocytosis:
The process of membrane and movement of material out of the cell is called exocytosis.

3. REGULATORY FUNCTIONS:
Plasma membrane consists of proteins which perform many regulatory functions of cell. e.g:
They acts as enzyme, responsible for specific functions of the membrane.

*NUCLEUS:
Discovery:
Nucleus was discovered by Robert Brown in 1831.

Definition:
“A very prominent spherical body present in typical cell that controls almost all of its
activities is usually referred to as nucleus.”
 It is a dense, deeply staining almost spherical
body, embedded in the cytoplasm.

Structure:
The nucleus has following parts.
i. Nuclear membrane
ii. Nucleoplasm/ karyoplasm /karyolymph
iii. Chromatin network
iv. Nucleoli

 Nuclear Membrane:
 It is thin, double membraned structure, which
surrounds the nucleus.
 The nuclear membrane is not a complete barrier.
 It is perforated by nuclear pores. Certain substances pass freely through these pores
between the nucleus and surrounding cellular substances.

 Karyoplasm:
It is clear structure less fluid, which fills the inner space of nucleus. It is mainly composed of
proteins.

 Chromatin Network:
 Suspended in the Karyoplasm are numerous fine thread like structures, which form
chromatin network.
 They are clearly visible during cell division and form definite number of chromosomes,
made up of DNA and protein.

 NUCLEOLUS:
 It is a rounded body in the nucleus.
 Its number is one or more in various types of nuclei.
 It disappears during cell division and reappears afterwards.
 The nucleolus is believed to play an important role in the synthesis of RNA and
ribosomes.

CHARACTERISTICS OF CHROMOSOMES:
 Chromosomes contain the hereditary unit called genes that carry the hereditary unit
called that carry the hereditary information from generation to generation.
 The chromosomes vary in number from species to species e.g.: 8 in butterfly, 46 in
human.
 A typical chromosome is composed of 2 parts the chromatid and centromere.
Chromatid consists of one or more threads called chromonema, which have bead area called
chromomeres.

STRUCTURAL TYPES OF CHROMOSOMES:

The chromosomes have different shapes, depending on the position of centromere. These
shapes are:
i.Metacentric:
Chromosomes with equal arms resembling the letter V.
ii.Sub-metacentric:
Chromosomes with unequal arms and resembling the letter J.
iii.Acrocentric or sub telocentric:
Rod like chromosome with one arm very small and other very long. The centromere is
subterminal.
iv.Telocentric:
Location of centromere at the end of chromosomes.

FUNCTIONS:
 The nucleus takes direct part in reproduction.
 It initiates cell division.
 It is regarded as a bearer of hereditary characters.
 It gives instructions to prepare all types of proteins.
 It controls all metabolic activities of a cell by producing enzymes.
 Ribosomes are produced in the nucleus of eukaryotic cells.

CELL WALL:
DEFINITION:
“Cell wall is a nonliving outermost structure responsible for support and is secreted and
maintained by the protoplasm”

In the young cell it is a thin and delicate but as the cell matures, the wall becomes thick due
to the deposition of chemical substances on the inner surface.

COMPOSITION:
 It is mainly composed of cellulose, which is a
carbohydrate.
 Other chemical substances are also present e.g:
pectin and lignin etc.
 Many layers of cell wall develop as the plant cell
grows.

CHARACTERISTIC FEATURES:
 Cell wall is hard, rigid and non-elastic structure that
surrounds a typical plant cell.
 It is a permeable to H2O and its dissolved contents.
 It is a non-living structure.
 The cell wall is pierced in many places by tiny pores,
through which protoplasm of one cell connects with that of
adjacent cell through which material can pass from one cell to the next. These pores are
called ‘plasmodesmata’.
 It is secreted and maintained by living portion of the cell called protoplasm.

STRUCTURE:
A plant cell wall can be differentiated into three regions.
1- Middle lamella
2- Primary wall (1.3µ m and elastic)
3- Secondary wall (5-10 µm, thick and rigid)

1-Middle Lamella:
i. The first formed cell plate works as a cementing layer between two daughter cells and it
is called middle lamella.
ii. It is a common layer between two cells and the two cells are separated when middle
lamella is dissolved.
iii. It is composed of Calcium and Magnesium pectates.

2-Primary Wall:
i. Bordering middle lamella, primary wall is the first product of cell, synthesis by
protoplast.
ii. In young enlarging cells primary wall remains thin and elastic becoming thick and rigid
with the approach of cell maturity.
iii. Primary cell wall contains hemi-cellulose upto 50%, cellulose upto 25% and smaller
amount of pectin.
iv. Hemi-cellulose forms matrix of the wall in which cellulose microfibrils are embeded.

3-Secondary Wall:
i. Secondary wall is formed by deposition of cellulose at the inside of primary wall.
ii. It mainly consists of cellulose or varying mixture of cellulose.
iii. Secondary wall may be modified through the deposition of lignin and other
substances.

FUNCTIONS:
 It maintains typical form of the plant cell.
 It protects the cell from external injuries.
 The cell wall forms the skeleton of plant body.
 It is responsible for the strength, rigidity and flexibility of plants.
 It is freely permeable layer.
 It provides a mechanical support.
 Being hydrophilic in nature it is capable of imbibing water and thus helps in the
movement of H2O and solutes towards protoplasm i.e: cell wall acts as a permeable
structure.

*CYTOPLASM:
Definition:
“The protoplasm of the cell outside the nucleus is called cytoplasm.”
1. The cytoplasm is a semi-fluid colloid that fills the cell.
2. It exhibits active streaming movements around the inner surface of the cell called
cyclosis.
 3. It has 2 distinct parts:
a.) The outer portion is called ectoplasm and it appears clear.
b.) The inner portion is called endoplasm and it appears granular.
4. Cytoplasm contains several types of organelles, embedded in a fluid matrix called the
cytosol containing salts, sugar, amino acids, proteins, fatty acids, nucleotides and other
substances.
5. The cytoplasm maintains shape with the help of a network of proteins fibers called
cytoskeleton, which is also connected to many organelles. It also helps the cells in
movement.
6. The cell organelles can be grouped on the basis of presence or absence of a membrane.

Cytoplasmic Organelles:
There are two types of cytoplasmic organelles.

*MEMBRANE BOUNDED ORGANELLES:

 Endoplasmic reticulum
 Golgi apparatus
 Plastids
 Glyoxysomes
 Mitochondria
 Lysosomes
 Peroxisomes
 Vacuoles

*NON-MEMBRANE BOUNDED ORGANELLES:

 Ribosomes
 centrosomes

*ENDOPLASMIC RETICULUM:
Introduction:
In the year 1945, there scientists PORTER, CLAUDE and FULLMAN discovered endoplasmic
reticulum in the cell.

Definition
“It is a network of fine tube like structures which extend from cell membrane to the nuclear
membrane.

Occurence:
They occur in all kinds of cell except bacterial and erythrocytes of mammals.

Composition:
 It is composed of lipid protein molecules.
 Also it is non-stable or fixed structure.
 It breaks up, reforms and regroups in response to cellular activities
 ER undergoes partial fragmentation at the time of cell division.

Functions:
Endoplasmic reticulum is associated with some general functions in the cell.
 a.) They form a structural frame work of the cell.
b.) They increase the surface area for various metabolic reactions.
c.) They actively participate in different metabolic reactions with the help of attached
enzymes.
d.) They also provide conducting pathways for import, export and intracellular
circulation of various substances.
e.) They also provide passage for RNA to pass from the nucleus to various organelles
in the cytoplasm and influence the synthesis of proteins.
f.) They also help in detoxification of harmful drugs, storage and release of calcium
ions, detoxification of chemicals and manufacture of lipids.

TYPES OF E.R:
There are two types of endoplasmic reticulum.

1: SMOOTH ENDOPLASMIC RETICULUM:

Definition:
Smooth endoplasmic reticulum does not contain ribosomes on their surface.

Location:
It is found in steroid producing cell, like fat cells, interstitial cells, like liver and muscle cells.

Structure:
It consists of an irregular network of membranous tubules and vesicles devoid of ribosomes.

FUNCTIONS:
i. This helps in lipid biosynthesis and intracellular transport.
ii. In skin it converts cholesterol into vitamin D.
iii. This vitamin helps to make bones strong and healthy.

2: ROUGH ENDOPLASMIC RETICULUM:

Definition:
Rough endoplasmic reticulum are those which contain ribosomes on their surface.

Structure:
It consists of an interconnecting network of membranous tubules, vesicles and flattened sacs.

Location:
Rough endoplasmic reticulum mostly in protein synthesizing cells e.g: cells of pancreas and
mammalian salivary glandular cells.

Functions:
Main function of RER is protein synthesis and its intracellular transport.
 *MITOCHONDRIA OR CHONDRIOSOMES:
Discovery:
These structures were discovered by Altman (1894) who called these particles resembling
bacteria possessing genetic information. The term mitochondria was given by Benda.

Definition:
They are small spherical or plate like bodies present in the cytoplasm of animals and plants.

Location:
Usually present in the region of the cell with the highest rate of metabolism e.g.: in skeletal
and cardiac muscles.

Composition
Mitochondria are composed of
i.Proteins 70%
ii.Phospholipids 25%
iii.RNA 5-7%
iv.DNA in traces
Matrix fluid consists of enzymes, ribosomes, salts, vitamins etc.
Size and Shape:
The size of mitochondria may range from 0.2-1.0µm in length. They may appear in spheres,
rods and threads.

Structure:
Mitochondria consist of three parts:

Outer membrane: It is smooth and consists of proteins and lipids.

Inner membrane: It forms numerous folds called ‘cristae’. On these cristae enzymes and co-
enzymes are present which help in the oxidation of starch, fatty acids and amino acids.
Matrix: It is central granular part. It contains many organic compounds.

Mitochondria exist semi-autonomously in the cell as they have their own DNA that directs
production of some of their component proteins by their own ribosomes, and they can
reproduce independently of the normal cell division cycle of the cells.

Mitochondria, which are present in a cell, come only from the mother as they are present in
eggs but not in the part of the sperm that enters the eggs.

FUNCTION:
Mitochondria are the main centers of intercellular energy production; they are called POWER
HOUSE of the cell. Almost all the respiratory activities take place in mitochondria.

*GOLGI BODIES:
Discovery:
The Golgi apparatus was first discovered by CAMILLO GOLGI, an Italian physicist in 1898.

Definition:
“The Golgi apparatus are tubular system with sacs and it has a parallel arranged, flattened
membrane bound vesicles which lack ribosomes.’’
“The Golgi apparatus is a system of canaliculi made up of flattened membrane bound
vesicles, which are arranged parallel to each other. They
are known as dictyosome in plants and lower
invertebrates”.

Location:
They are typically located near the nucleus
membrane.

Components:
Each golgi body consist of
i- Flattened sac like structures called
cristae. Golgi body has 3-20 cisternae.
ii- Outer network of connecting tubules is
present at the edge of cisternae.
iii- Certain vesicles or golgian vacuoles.

Quantity:
The number of golgi bodies in a cell may be very large; usually it varies from 3-15 per cell. It is
absent in bacteria and RBCs of mammals.
 Occurence:
In animal cells single golgi apparatus is found in each cell, but in plant cell they are found
throughout the cell cytoplasm.

FUNCTIONS:
i.They are concerned with cell secretions.
ii.They manufacture certain macromolecules.
iii.They help in the synthesis of cell wall and plate material in plant cell.
iv.They manufacture lysosomes as well in animal cells.

*LYSOSOMES:
Discovery:
They were isolated by DEDUVE in 1949.

Definition:
They are small spherical bodies few micrometer in size surrounded by single membrane
originated by golgi apparatus and containing digestive enzymes.

Occurence:
They occur only in the cytoplasm of animal cell. They are rich in acid phosphatases and
hydrolytic enzymes.

FUNCTION
• They contain digestive enzymes and usually take part in the digestion of food.
• They also destroy unnecessary particles.
 They perform the breakdown of bacteria, warm out cells or other harmful foreign
material engulfed by WBCs by the process of phagocytosis.

Suicide Sacs:
They are also called ‘suicide sacs’. When their membrane ruptures the cell starts its chemical
breakdown because due to secretion of enzymes the cell uses its own protein for digestion.
This process is called lysis or autophagy.

LYSOSOMAL STORAGE DISEASES:

In 1905 W.G Hers of Belgium explained how the absence of apparently unimportant
lysosomal enzyme α-glucosidase could lead to the storage of undigested glycogen causing
swelling of the organelles and can results over 30 diseases. Some of them are:
 TAY-SACHS DISEASES:
Mental retardation , blindness , death by age 3.
 GAUCHER’S DISEASES:
Liver and spleen enlargement , erosion of long bone , mental retardation in infantile form
only.
 KRABBE’S DISEASES:
Loss of myelin, mental retardation , death by age 2.

*PLASTIDS
Introduction
Plastids, along with all cell walls are truly distinctive plant structures. They originate from
minute defined precursor structures called proplastids.
Definition:
These are special protoplasmic, membrane bounded, oval shaped organelles which function
as chemical synthesizers and storage bodies.

Occurence:
Plastids occur in greatest number in cells of plants and in the primitive single cell organisms
e.g: Euglena

TYPES OF PLASTIDS:
There are three types of plastids.
i. Chloroplast
ii. Chromoplast
iii. Leucoplast

i. Chloroplast: ( chloro:green , plast:living)

Definition:
The chloroplast is the green plastids which are most important of the plastids and are
scattered in the cytoplasm.

Occurence:
They contain chlorophyll and are found in parts exposed to light and occur in great number in
green leaves.

Importance:
They contain their own DNA and RNA.

FUNCTION:
They manufacture the food material in the presence of sunlight by the help of CO2 and H2O.

ii. Chromoplast: ( chroma:colour, plast:living )

Definition
These are coloured plastids which are mostly present in the petals of flowers and fruits.

Pigments:
The plastids may be yellow, orange or red because of the presence of xanthophyll (yellow)
and carotene (orange, red). They may be also show other colours.

FUNCTIONS:
Due to the presence of plastids the petals of flower become showy to invite for pollinations.

iii. Leucoplast: ( leuco:white , plast:living )

Definition:
These are colourless plastids which develop in the absence of sunlight.

Occurrence:
They are found in the storage cells of roots and underground stem.

FUNCTION:
They convert sugar into starch for the purpose of storage. They store carbohydrates, protein
and lipids,

*PEROXISOME:
Definition:
Peroxisomes are single membrane bounded micro-bodies that contain enzyme for
transferring hydrogen atom to oxygen to form hydrogen peroxide (H2o2).

Occurrence:
Peroxisomes are found in the cells which metabolize alcohol. The peroxisomes are also
present in yeast, protozoa and many cells of higher plants.

Enzymatic Activity:
They also produce other enzymes such as peroxidase, glycolic and acid kinase etc.
H2O2: It is a toxic compound which is immediately converted into H2O by catalase enzyme.

FUNCTION:
They take part to destroy the toxic effect of alcohol.

*GLYOXYSOMES:
Glyoxysomes were discovered by scientist named BEAVERS.

Definition:
These are micro-bodies covered by single membrane which produce network of spindle
fibers which help in cell division.

Location:
They are usually found in plant cells. This organelle is present only in the germination of lipid
rich seed and it is absent poor seed such as pea.

Enzymatic Activity
 They secrete enzyme which metabolize the oxidation of stored fatty acids to provide energy
for the formation of new plant.

FUNCTION:
The glyoxysomes secrete enzymes which take part to activate the enzymes and molecules of
photosynthesis and respiration by fatty acid oxidation, especially in seedlings.

*CYTOSKELETON:
Definition:
Cytosol is organized into three dimensional network of the fibrous protein called
‘cytoskeleton’.

FUNCTIONS:
It plays fundamental roles in:
i. Mitosis
ii. Meiosis
iii. Cytokinesis
iv. Cell wall deposition
v. Maintenance of shape
vi. Cell differentiation

TYPES:
There are major two types of cytoskeleton.
i. Microtubules
ii. Microfilaments
iii. Intermediate filaments.

Microtubules:
These are long, straight hollow cylinder like structure composed of a globular protein called
‘tubulin’.

Characteristics:
Their outer diameter is 25 cm.Their single microtubule consists of numerous sub-units of
tubulin arranged in 13 columns called ‘protofilaments’.
 They help in the storage of cellulose and movement of chromosomes during cell division.

-Microfilaments:
These are solid tube like structures made up of globular protein called ‘actin’.

Characteristics:
 Their diameter is about 7nm.
 Each microfilament consists of two actin chains arranged in helical manner.

Function:
Microfilament helps in internal motion of the cell

Intermediate Filament:
These are intermediate in size between microtubules and microfilaments.
Shape:
Their shape is rope like in different tissues. In hair and skin they consist of keratin protein.
Diameter:
Their diameter is range about 8nm-11nm

Function:
They are important in maintenance of shape of cell and may have the function of supporting
the other elements of cytoskeleton.

*RIBOSOMES:
Very small, oval shaped, non-membranous granules of a cell are known as ribosomes. These
are so named because they contain high concentration of Ribonucleic acid(RNA)

Characteristic Features:
• Ribosomes occur in all kind of cells, from bacteria to complex plant and animal cells
• Ribosomes are found freely dispersed in the cytoplasm in the prokaryotic cells, but in
eukaryotic cells they are found free as well as attached to the endoplasmic reticulum.

Chemical Composition:
Chemically ribosomes are composed of following substances:
• Proteins: They are composed of 50 or more types of proteins
• RNA: A special type of RNA is found in ribosomes called ribosomal RNA or rRNA.

Structure:
• Ribosomes are generally oblate and spheroid tiny granules
• Each ribosome consists of two unequal subunits. The larger subunit is dome shaped
and smaller one forms a cap on the flat surface of larger subunit
• Ribosomes adhere themselves to endoplasmic reticulum by the larger subunits
Formation of Ribsomes:
Recent investigation reveals that the ribosomes are manufactured in the nucleolus from
where they are transferred to the cytoplasm through nucleoplasm

FUNCTION:
Ribosomes are regarded as protein factories. Under directions by the nucleus they produce
the protein needed throughout the cell.

*CENTROSOMES:
In the cytoplasm, near nucleus most of the animal cells and certain lower plants cells a
centrosome is commonly present

Structure:
• Centrosome consists of a pair of organelles called centrioles
• Each centriole is a cylinder, about 0.2 nm in diameter
• It consist of 9 parallel triplets of hollow cylindrical microtubules
• Each member of centrosome move to opposite side of the cell during division and
thread like fibers begin to radiate from the centriole in all directions called Astral rays

FUNCTIONS:
• The centrioles are active at the time of cell division in annimal cells, where they
separate and move to form the poles of nuclear spindles
Microtubules of cells are also formed by centrosome
• They also play a role in the formation of contractile structures of cilia and flagella in
certain cells

VACUOLES:
Vacuoles are non-protoplasmic liquid filled cavities in the cytoplasm and are surrounded by a
selectively permeable membrane called tonoplast.
 In animal cells they are formed temporarily when needed. They are rich in hydrolytic
enzymes such as proteases, ribonucleases and glycosidase. Some of the vacuoles act
as lysosomes. They may initiate cell death by altering the differential permeability of
the tonoplast causing enzymatic lysis of the cell.
 Vacuoles are very prominent and large in the plant cells and are filled with cell sap
and act as a storehouse for different substances. They also help in plant defence, cell
growth and enlargement.
 They are more prominent in mature cells and are small in developing cells.
 CHAPTER 5 : VARIETY OF LIFE
SCHEME OF CLASSIFICATION:

1. Specie: The basic unit of classification is the species. Species is a group of organisms
which have numerous features in common and which are normally capable of
interbreeding and producing viable fertile offspring.
2. Genera: Closely related species are grouped together into genera (sing: genus).
3. Families: Genera are grouped together into families
4. Orders: Families into orders.
5. Classes: Orders into classes.
6. Phyla: Classes into phyla.(Singular : Phylum)
7. . Kingdom: Phyla into kingdoms (when classifying plants & bacteria the term division is
sometimes used instead of phylum.)

BIONOMIAL NOMENCLATURE:
The modern system of naming species also dates from "Linnaeus”. Before him there had
been little uniformity in the designation of species. Some species had a one word name
others had 2 word names and still others had names consisting of long descriptive phrases.
Linnaeus simplified things by giving each species a name consisting of 2 words: first the name
of the genus to which the species belongs and second name a designation for that particular
species. The genus name is capitalized while the specific name is not. Both the names are
customarily printed in italics (underlined if handwritten).This is called "Binomial
Nomenclature"

EXAMPLES:
Some common examples are given in the following table:
No. Common name Biological name
1. Man Homosapiens
2. Frog Rana tigrina
3. Earthworm Pheretima posthuma
4. Cockroach Periplanata americana
5. Potato Solanum tuberosum

FIVE KINGDOM SYSTEM:

Introduction:
This scheme was proposed by an American biologist, Robert H. Whittaker in 1969.He based
his classification on two main criteria the level of organization of the organisms and their
modes of nutrition.

On this basis Robert H. Whittaker suggested the following five systems:

KINGDOM MONERA:
Monera include unicellular prokaryotes which feed by a variety of different methods.
E.g. Bacteria, Cyanobacteria etc.

KINGDOM PROTISTA:
It includes unicellular eukaryotes.
E.g :Ameoba, Paramecium etc.

KINGDOM FUNGI:
They are multicellular eukaryotes, which feed heterotrophically by absorption. They are non
chlorophyllous and cell wall is always present
E.g: Rhizopus, Mucor etc

KINGDOM PLANTAE:
They are multicellular chlorophyllous eukaryotes which feed autotrophically by
photosynthesis. Cell wall always present
e.g: Wheat, Mustard etc.

KINGDOM ANAMALIA:
It comprises multicellular eukaryotes which feed heterotrophically by ingestion. They have
neither chlorophyll nor cell wal
l e.g.: Cow, Spider etc.

MODIFICATION OF WHITTAKER’S SCHEME:

INTRODUCTION:
Two American biologists L. Margulies and K. Schwartz put forward a little modification of
Whittaker's scheme. They suggested that the multicellular algae should be removed from the
plant kingdom and placed along with the entire protoctist kingdom containing unicellular
organisms, which would replace Whittaker's kingdom Protista. This makes the plant kingdom
a more natural group and it brings the multicellular algae close to their unicellular relatives.
Viruses are not included in the five kingdoms the reasons centers on the controversy which
has been going on ever since they were discovered, as to whether or not they should be
regarded as living. A virus consists simply of nucleic acid surrounded by a protein coat and it
can only survive and reproduce inside a living cell. For these reasons most reasons most
biologists regard it, not as living organism but as aggregation of molecules similar to those
normally found in living cells Virus appear to be on on the borderline between the living and
non-living worlds.

According to L. Margulis and K. Schwartz the modification of Whitakker's

scheme as follows:

KINGDOM PROKARYOTAE (MONERA):

It includes almost all prokaryotes
e.g: Bacteria and Cyanobacteria etc.

KINGDOM PROTOCTISTA (PROTISTA):

It includes all the unicellular eukaryotic organisms, which are no longer classified as animal,
plant or fungi.
e.g.: Euglena, paramecium, chlamydomonas, plasmodium, multicellular algae (ulva) etc.

KINGDOM FUNGI:
It includes non chlorophyllous, multicellular (except yeast) organism having chitinous cell wall
and coenocytic body called mycelium.
E.g. Agaricus (mushroom) etc.
 KINGDOM PLANTAE:
It includes all the chlorophyllous multicellular eukaryotic living organisms having cellulose cell
wall and zygote developing into embryo.
E.g. Apple, sunflower etc.

KINGDOM ANIMALIA:
It includes all the non chlorophyllous multicellular eukaryotic organisms having no cell wall.
E.g. Hydra, earthworm, human, etc.

VIRUSES:
Viruses are non-cellular obligate parasites that always have a protein coat and a nucleic acid
core.

Discovery:
 The word Virus is derived from Latin word meaning "poison."
 Virus was discovered by Iwanowski in 1892. He observed that a virus could be transmitted
from an infected organism to a healthy organism of the same kind.
 In 1935 W.M Stanley an American microbiologist succeeded in isolating Tobacco Mosaic Virus
(TMV) from host cell.

CHARACTERISTIC FEATURES:
Size of Virus:
Viruses vary considerable in size but, in general they are well below the limit of visibility of
light microscope. The size ranges from 20nm to 250nm

Nature
Virus can be found in any one of the following natures
Virulent: Destroying the cell in which they occur
Temperate: Becoming integrated into their host genome and remaining stable there for long
periods of time.

CHEMISTRY OF VIRUS:
 Virus is basically made up of nucleic acid which may be either DNA or RNA.
 Nucleic acid is surrounded by capsid, which is made up of protein.
 Some viruses attain additional structural protein, enzymes and carbohydrates.
 The simplest viruses use the enzymes of host cell for protein synthesis and gene replication.
 The more complex ones contain upto 200 genes and are capable of synthesizing through
their host, many structural proteins and enzymes.

STRUCTURE:
Electron microscope study reveals the following features of virus:
 Virus appears like little spheres or golf balls, rod shaped like tadpoles and may be polyhedral.
 Viruses are non-cellular having no cell wall, cell membrane, cytoplasm and even no nucleus.
 The shape of virus is determined by organization of subunits that made up the capsid.

Virus may consist of following structures:

1. GENOME: Their genome (sets of genes) may consist of a single or several molecules of DNA
or RNA. The smallest viruses have only four genes while the largest have hundreds.
2. CAPSID: The protein coat that encloses the viral genome is called a capsid. It may be of
different shapes. Capsid is made up of protein subunits called capsomeres. The number of
capsomeres is characteristic of a particular virus.

3. VIRAL ENVELOPE: Some viruses have accessory structures called viral envelopes that help
them infect their hosts. They are membranes cloaking their capsid.

4. TAIL FIBRES: Some viruses like bacteriophage have tail piece with tail fibers.

VIRUSES- LIVING OR NON LIVING:

Viruses show many of characteristics of living organisms. These are:
1. Property of replication
2. The core of DNA and coat of protein
3. The hereditary instruction-the genes of virus can undergo mutations
4. In viruses, genetic recombination, reshuffling of heritable material takes place

They also show some features of non-living things:

1. They can be crystallized like non-living compounds.
2. They do not have any metabolic system.
3. They have no respiratory, excretory, digestive, circulatory or co-coordinating system.
4. Basic characters of cell are not present.
5. They are completely inactive outside the host cell.

CLASSIFICATION:
Viruses are generally classified on the basis of morphology and nucleic acid, they contain.
Hence there are two main types of viruses RNA and DNA viruses.

RNA VIRUSES:
The viruses which contain a central core of Ribonucleic acid are referred to as RNA viruses.
They are further divided into following main types:
1. Plus strand RNA virus
2. Minus strand RNA virus
3. Double strand RNA virus
4. Viroid’s

 PLUS STRAND RNA VIRUS:

They are called plus strand because they act directly as mRNA after infecting a host cell,
attaching to the host's ribosomes and being translated. They are subdivided into non
enveloped and enveloped viruses.

a) Non enveloped viruses: As indicated by their name these viruses lack envelope and
consist of Nucleic acid core surrounded by protein capsid.
EXAMPLE: Polio virus, Rhino virus, Hepatitis A virus.

b) Enveloped viruses: The enveloped plus strand RNA viruses, all of which parasitize
animals are distinguished from the members of preceding group by their lipid rich
envelopes. These envelopes belong to the host cell membrane.
EXAMPLE: Yellow fever virus, Dengue virus, Hepatitis C virus, Rubella virus.
  MINUS STRAND RNA VIRUS:
Minus strand RNA viruses are distinguished from plus strand RNA viruses because they carry
the RNA strand complementary to the mRNA that carries the genetic information of
appropriate mRNA which then functions in the cell.
EXAMPLES: Rabies virus, Measles, Mumps.

 VIROIDS:
Viroids are infectious circular molecules of RNA that include 250 to 400 nucleotides. Viroids
lack capsids and have no protein associated with them. They cause several plant diseases but
are not implicated in any human disease.

 DOUBLE SRAND RNA VIRUSES:

They have 10 segments of double strand of linear RNA molecules. Their capsids are

icosahedral in shape
EXAMPLES: Reovirus & Rotavirus.

DNA VIRUSES:
Such type of viruses that contains DNA as a central core are known as DNA viruses. These are
further divided into three types:
1. Small genome viruses
2. Medium & large genome viruses
3. Bacteriophage

 SMALL GENOME DNA VIRUSES:

Many DNA viruses have small genomes; some of these viruses have single stranded DNA,
others have double stranded DNA
Examples: Among them are the parvoviruses, which infect animals, they are icosahedral and
about 20nm in diameter

 MEDIUM & LARGE GENOME DNA VIRUSES:

These are double stranded DNA viruses, which infect man and other animals
Examples: Papillomavirus, Adenovirus, Hepatitis B virus, Herpes virus, Cytomegalovirus, Small
pox virus.

 BACTERIOPHAGE:
A virus that infects bacteria is known as Bacteriophage.
 They are amongst the most complex viruses.
 Each of them is made up of atleast 5 separate proteins, these make up the head, the tail,
core and molecules of the capsid, the base plate of the tail and the tail fibers.
 A long DNA molecule is coiled within the head.

THE LYTIC CYCLE:

A viral reproductive cycle that culminates in the death of the host cell is known as lytic cycle.
 The term refers to the last stage of infection, during which the bacterium lyses(breaks open)
and releases the phages that were produced within the cell
 Each of these phages can then infect a healthy cell and a few successive lytic cycles can
destroy the entire bacterial colony in a few hours
 A virus that produces only by a lytic cycle is a virulent virus
 Life cycle of lytic phage can best be understood by considering T4 phage

MAIN STAGES OF LYTIC CYCLE:

ATTACHMENT:
The T4 phage uses its tail fibers to stick to specific receptor sites on the outer surface of an
E.coli cell (Escherichia coli).

PENETRATION:
The sheath of the tail contracts; thrusting a hollow core through the wall and membrane of
the cell. The phage injects its DNA into the cell. The empty capsid of the phage is left as a
ghost outside the cell0

EFFECT ON HOST:
 The cell's DNA is hydrolyzed
 The cell's metabolic machinery ,directed by phage DNA ,produces phage proteins and
nucleotides from the cell's degraded DNA are used to make copies of the phage genome
 The phage parts come together. Three separate sets of proteins assemble to form phage
heads, tails and tail fibers forming daughter phages
 These phages then direct direct production of enzyme (lysozyme) that digests the bacterial
cell wall .With the damaged wall, osmosis causes the cell to swell and finally to burst
,releasing 100-200 phage particles
 During lytic cycle of a bacteriophage the bacterial cell dies when the viral particles bursts
from the cell(Fig:5.6,pg:91)

THE LYSOGENIC CYCLE:

In contrast to the lytic cycle, this kills the host cell; the lysogenic cycle replicates the viral
genome without destroying the host
Viruses that are capable of using both modes of reproduction within a bacterium are called
"temperate viruses"

MAIN STAGES OF LYSOGENIC CYCLE:

To illustrate various stages of lysogenic cycle we consider a phage called lambda phage. It is
abbreviated with the Greek letter λ .It resembles T4 but its tail has only single short tail fiber.
The main stages of the life cycle are:

ATTACHEMENT:
Infection of an E.coli cell by λ begins when the phage binds to the surface of the cell and
becomes ready to inject its DNA within the host

PENETRATION:
DNA penetrates into the host, leaving the capsid outside. The DNA molecule forms a circle

EFFECTS ON THE HOST:

Viral DNA is incorporated by genetic recombination into a specific site on the host cell's
chromosomes (chromatin body)
It is known as prophage. One prophage gene codes for a protein that represents most of the
other prophage genes. Thus, the phage genome is mostly silent within the bacterium
Every time the E.coli prepares to divides it replicates the phage DNA along with its own and
passes on the copies to the daughter cells.

A single infected cell can soon give rise to a large population of bacteria carrying the virus in
prophage form. This mechanism enables viruses to propagate without killing the host cells
upon which they depend.

The term lysogenic implies that prophage can, at some point, give rise to active phages that
lyse their host cells. This occurs when the λ genome exists the bacterial chromosome

At this time ,the viral genome commands the host cell to manufacture complete phages and
then self-destruct ,releasing the infectious phage particles

It is usually an environmental trigger, such as radiation or the presence of certain

chemicals, which switches the virus from the lysogenic to the lytic mode.(Fig:5.7,pg:92)

VIRAL DISEASES:-
1.POLIOMYELITIS:
Causative Agent:
It is caused by polio virus, which is type of non-enveloped RNA virus.

Epidemiology:
It was a widespread crippling disease through the first half of the twentieth century. Although
poliomyelitis is now largely under control by vaccination in the industrialized countries. It
remains a serious and common disease in the tropics and elsewhere in the less developed
parts of the world.

Transmission:
It is transmitted through oral-fecal route.

Signs & Symptoms:

Mostly children are affected.
Mild fever, headache, nausea and vomiting are initial symptoms
In some patients, paralysis takes place.

Pathophysiology:
It enters the digestive tract, through mouth from where it penetrates into the blood vessels.
By the circulation of blood it reaches to the nervous system & affects the nerve cells. It
causes paralysis

Control:
Vaccination of babies
Contaminated food and H20 should not be used.

2.COLDS:
These are infections of upper respiratory tract.
Causative Agents:
About 1/3 of all colds are caused by rhinoviruses, which are non-enveloped plus strand RNA
viruses
 Transmission & Spread:
It is transmitted directly from person to person via aerosols of respiratory droplets
Signs & Symptoms:
After an incubation period of 2 to 4 days following signs & symptoms are observed.
*Sneezing *Nasal discharge *Sore throat
*Cough *Headache

Vaccinations:
There are dozens of different strains of cold causing rhinoviruses alone, each of them with
different properties and none conferring cross immunity to the others. More than 200 of
viruses that cause colds have been identified; this makes the development of appropriate
immunization methods very difficult, if not impossible.

3.RABIES:
Rabies was the subject of path - breaking discoveries of Louis Pasteur in the 19th century.

Causative Agents:
It is caused by rhabdovirus, a type of enveloped RNA virus

Spread:
Today rabies is most often spread by small, mammals such as dogs, raccoons and foxes. The
rabies virus is spread by the saliva of host animal, often after bites, but it can also be
contracted from handling a dead infected animal. An animal infected with rabies may go into
a mad frenzy, often running great distances in its confusion.

 Sign & Symptoms:

*After incubation period of 2 weeks to 16 weeks following signs & symptoms may be seen.
*Fever, anorexia and sensational changes at the bite site are initial symptoms.
*Within a few days, confusion, lethargy and increased salivation develops
*Painful spasm of throat muscles.
*Hydrophobia.
*Fits, paralysis and comma are advanced symptoms.

Vaccinations:
Fortunately, it is simple matter to vaccinate pets against rabies and human vaccines are also
being developed.

4.AIDS:
Causative Agents:
AIDS (Acquired Immunodeficiency Syndrome) is caused by HIV (Human Immunodeficiency
Virus), a retrovirus, which is a single stranded enveloped RNA virus.

Pathophysiology:
HIV infects the lymphocytic cells T4 (helper T cells) which is a very important part of immune
system.
Due to this virus, the lymphocytic cells T4 immune system of the body becomes very weak.
The virus replicates in T4 cells or helper cells.
These affected cells do not motivate other T-cells to fight against virus
When the body of host is affected by the virus continuously, helper T cells are decreased.
 By their reduced number immune system is damaged.

Transmission:
The HIV virus can be transmitted to other persons by blood or semen, because it is active
only in body fluid. In this way, there are two methods of its transmission:

1. Infected Blood:
There are different ways of entering of infected blood into the body of healthy person.
These are as follows:

*Blood transfusion:
When already infected blood by HIV is transfused into the body of a person, then this virus
enters the body.

*By intravenous methods:

When unsterilized syringes & needles are used. HIV may enter the body. The intravenous
drug users are actively involved in spreading the disease.
*Through cuts & wounds:
Through cuts and open wounds virus can be transfused from one person to another.

*From mother to baby:

Virus can be transfused from mother to baby through placenta at birth or through milk food
from mother.

2. Sexual Contact:
Sexual contact is the main cause of transmitting the virus from infected person to non-
infected person.

Signs & Symptoms:

*Flu like Illness:

In the beginning flu like illness & for months or years no prominent symptoms of disease.

*Immune Deficiency:
Immune system is damaged i.e. Immune deficiency is the main symptom.

*Kaposis Sarcoma:
Skin cancer called "Kaposi's Sarcoma" may occur. It causes death.

*Mental Agity:
Lymphocytes are affected so the brain cells are damaged, brain shrinks, memory loss, mental
disorder takes place .Behavior of patient is also changed.

*Septimicimea :(Blood Poisoning):

Other common sign & symptoms of AIDS included Pneumonia, fever, dementia, diarrhoea,
weight loss etc.

Control:
These are 2 lines of research. One into developing drugs which can be used to cure the
disease & one into developing a vaccine.
 Both approaches are at an early stage & require heavy financial investment
In the short term the aim is to develop drugs to inactivate the virus by blocking the
pathogens metabolism.

Medical Treatment:
AIDS can be treated by the use of following drugs:
*Zidovadine:
The best drug is azidothymidine or zidovudine commonly known as AZT. This drug was
prepared in 1987.It slows progression of the disease & can attack the virus even the brain

*Ribavarin:
Another drug Ribavirin is used to treat other viral infection. It suppresses the AIDS virus.

*Sumarin:
Sumarin drug is also effective to control the viral reproduction in host body.

Methods Of Prevention:
AIDS can be prevented by following methods:

*Clean Needles:
The reduction in the spread of HIV could be brought about by the use of clean needles.

*Examination Of blood:
Before transfusion blood should be properly examined and checked. It should be healthy and
without infection.

*Avoidance Of Close Contact:

Close contact with infected person should be avoided.

*Education And Awareness:

Proper guideline by education should be provided to people. They should be aware of the
disease.

5.HEPATITIS:
Definition:
Hepatitis is an inflammation of the liver. It may be due to viral infection, toxic agents or
drugs. It is characterized by jaundice, abdominal pain, liver enlargement, fatigue and
sometimes fever. There are various types of viral hepatitis:
1. HEPATITIS-A:
It is an infection of liver caused by hepatitis A virus (HIV).

Causative Agent:
It is caused by a type of picornavirus, which is a non-enveloped RNA virus

 Transmission:
HIV is transmitted by contact with faeces from infected individuals.

 Signs And Symptoms

It is an acute disease. After a short incubation period (3-4 weeks),following signs and
 symptoms may appear.
*Fever *Jaundice *Nausea
*Anorexia *Vomiting
Most resolve spontaneously after 2-4 weeks.

 VACCINATION:
Vaccine, containing inactivated HAV is available.

2. HEPATITIS-B:
It is an acute or chronic liver infection, caused by hepatitis B virus(HBV).

 Causative Agent:
HBV is a type of Hepadnavirus, which is an enveloped double strand DNA virus (unusual DNA
virus).

 Properties:
HBV contains a small, circular molecule of partly but not completely, double stranded DNA.
The viral genome encodes 2 kind of proteins, a core protein and a surface protein, as well as
DNA polymerase.
The amount of genetic information in the hepatitis B viral genome -359 nucleotides is less
than that of any other pathogen, except of the viroids.

 Epidemiology:
The hepatitis B virus possess a serious health problem, particularly among Asians, Africans
and male homosexuals
It often persists in cancers without causing any symptoms, but it may still be highly infectious
People infected early in life often become carriers, and it is estimated that there are about
200 million such carriers worldwide
Since most of these people are not recognized as carriers, there is a real possibility of the
frequent transmission of hepatitis through skin contacts, blood transfusion and similar
medical procedures

 Sign & Symptoms

In acute cases, sign and symptoms appear after an incubation period of 10-12 weeks, which
are very similar to those of HAV infection
In chronic cases, the patients may remain symptomless for years

 Complication:
Not only is the hepatitis itself serious, but the virus also may play a role in causing human
liver cancer, even among carriers who show no other symptoms

 Vaccination
New vaccines against the virus have been produced by recombinant DNA technology & are of
great importance, especially for those who require frequent blood transfusion, and other
who run a severe and continuing risk of infection

3. HEPATITIS-C:
It is also a serious viral infection of liver
 Causative Agent:
The causative agent is hepatitis C virus, which is a type of Flavivirus.
Properties
HCV is single stranded RNA virus
It is enveloped type
Multiple serotypes exist

Transmission: It is transmitted via blood, sexually & from mother to child

 Signs And Symptoms:

Acute infection is milder than other types of hepatitis. Signs & symptoms are similar to those
of HIV infection
Chronic infection may be asymptomatic as associated with hepatocellular carcinoma

 Vaccinations
Vaccine is not available.
 CHAPTER 6: THE KINGDOM PROKARYOTAE
 BACTERIA:
Bacteria are the minute, simple, unicellular, non-protozoans prokaryotic and microscopic
organisms.

 DISCOVERY:
Bacteria were first discovered by Antony Van Leeuwenhook in 1676 in Holland.

CHARACTERISTIC FEATURES:

HABIT & HABITAT:

Bacteria are omnipresent and distributed all over the world.
Bacteria occur in wide range of temperatures.
Some species of bacteria occur in sulphur springs also.
Bits of rocks are ice drilled from depths 430 m in Antarctica contained bacteria.

SIZE:
Bacterial cell measures from 0.2 micron (µ) to 2(µ) in breadth and 2-10 (µ) in length.

 STRUCTURE OF BACTERIA:
A generalized bacterial cell consists of following structures.

 Flagella:
They are extremely thin appendages. They originate from basal body, a structure in the
cytoplasm beneath cell membrane. They come out of cell. Flagella helps in motility.

 Pilli:
They are hollow filamentous appendages smaller than flagella. They help in conjugation &
not in locomotion.

 Capsule:
It is a protective shield made up of polysaccharide and proteins. Some bacteria have
SLIME CAPSULE which provides greater pathogenicity and protects them against
phagocytosis.

 Cell Wall:
 It is totally different from ordinary plant cell wall. It is chemically complex and made
up of amino acids, sugar and chitin but cellulose is totally missing.
 Cell wall determines the shape and protects from osmotic lysis. Christian Gram
developed the technique of gram stain dividing bacteria into two groups. Gram positive
bacteria stained purple and gram negative stained pink.
 It may be composed of following chemical substances.

*Peptidoglycans
*Teichoic acid
*Lipoprotein
*Lipopolysaccharide
  Cell Membrane:
It lies inside cell wall. It is attached to cell wall at few places and has many pores. It is
made up of lipids and proteins. It acts as respiratory structure as mitochondria are
absent.

 Cytoplasm:
Cytoplasm is granular having small vacuoles, glycogen particles and ribosomes. Other
membrane bounded organelles are absent.

 Mesosomes:
These are invagination of cell membrane into the cytoplasm. Mesosomes are in the form of
vesicles, tubules or lamellae. Their function is to help in DNA replication, cell division, respiration
and in export of enzymes.

 Chromatin Bodies & Plasmids:

Nucleus is absent. However, hereditary material DNA is found as contracted structures called
"bacterial chromosomes" or "chromatin bodies”. In addition, a small fragment of extra
chromosomal circular DNA called plasmid is also present.

 FORMS (SHAPES) OF BACTERIA:

Bacteria are classified into the following four categories on the basis of shape and form
1. Cocci (sing:-coccus: Greek Kokkos=berry, round)
2. Bacilli (sing: bacillus: Latin Bakulus=rod)
3. Spirilla (spirillum: Greek speira=coil)
4. Vibrio

1. COCCI: They are spherical, on flagellated bacteria. They can be subdivided into
following types:

MONOCOCCUS: Single round shaped bacterium

 DIPLOCOCCUS: is found in a pair of bacteria.

STREPTOCOCCUS: is a long chain of cocci.

STAPHYLOCOCCUS: has a grape like arrangement.

TETRAD: consist of four cocci.

SARCINA: is a cube of eight cocci.

2. .BACILLI: They are rod shaped and are found in pairs or in chains. Flagella may be
present. There are two main types of bacilli.

STREPTOBACILLI: is a chain of bacilli.

DIPLOBACILLI: is a pair of bacilli Example : pseudomonas, salmonella typhi, shigella, klebsella.

3. SPIRILLA: They are spiral or cork screw shape Example: Spirochaeta.

4. VIBRIO: They are slightly curved and comma shaped. Flagella may be present.Example :
Vibrio cholera is a common example.

 NUTRITION IN BACTERIA: Most bacteria are heterotrophic with a few autotrophic.

Heterotrophic bacteria cannot synthesize their organic food from complex organic substances,
but autotrophic bacteria can synthesize their food.

Major types of heterotrophic & autotrophic bacteria are mentioned below:

HETEROTROPHIC BACTERIA:

1.PARASITIC BACTERIA:

They live on or in the bodies of other living organisms. They may be pathogenic or nonpathogenic.
These bacteria lack certain complex systems of enzymes

E.g: Pneumococcus, Salmonella

2.SAPROTROPHIC BACTERIA:

These bacteria acquire their food from dead and decaying organic matter. In the course of
obtaining food, these bacteria break down complex organic compounds into simpler products by
secreting enzymes

E.g. Rhodospirillum rubrum

3.SYMBIOTIC BACTERIA:

They occur as symbionts i.e. associated with other living organisms and both partners get benefit
from each other.

Example: Rhizobium radicicola found associated with nodulated roots of leguminous plants e.g.
 Pisum sativum.

AUTOTROPHIC BACTERIA:

They can synthesize organic compounds from simple in organic substances. There are 2 main
types of autotrophic bacteria.

1. PHOTOSYNTHETIC BACTERIA:

These are discovered by Von Neil in 1930.They have two pigments, very similar to the chlorophyll
and named as bacteriochlorophyll and chlorobium-chlorophyll organized in chromatophores.
During photosynthesis bacteria utilized H2S instead of water and liberate sulphur instead of
oxygen.

light
CO2+2H2S (CH2O) n+H2O+2S
chloropyll

E.g. Chlorobium, chloroflexus

2. CHEMOSYNTHETIC BACTERIA:

They obtain energy from oxidation of certain inorganic compounds (ions, sulphur, and nitrogen)
for the manufacturing of their food. E.g. Nitrobacter, Nitrosomonas, Methnococcus.

Chemical Equation:-
NH4 + 2O2 2NO2 + 4H+ + Energy

Another bacterium oxidize nitrites NO22  to nitrates.

2NO2 + O2 2NO3 + Energy

 RESPIRATION:

The process of oxidation of nutrients in the living organisms to produce energy is known as
respiration.

This is another basis of classifying bacteria so bacteria can also be classified into the following
types:

*Aerobes

*Obligate anaerobes

*Facultative anaerobes

*Microaerophiles
 AEROBES:
They require oxygen for respiration. They are further classified into following groups according to the
amount of O2 needed for their survival.

a. Obligate Aerobes:
These bacteria require normal concentration of oxygen and will not survive in low
concentration.

b. Facultative Aerobes:
They use oxygen if it is present but can survive without oxygen.

c. Micro-aerophillic:
They are aerobic but require low concentration of O2.

Example: Methylcoccus, Brucella.

ANAEROBES:
These bacteria respire without oxygen. They are further classified into following groups according to
the nature of anaerobic respiration.

a. Obligate anaerobes:

The bacteria which obtain energy by means of reactions that do not involve the utilization of
molecular oxygen are referred to as obligate anaerobes. Oxygen is toxic to them and they cannot
grow in the presence of air. E.g. Bacteroides fragilis

b. Facultative Anaerobes:

Those organisms which do not require oxygen for their growth but can use it when it is available
are known as facultative bacteria. They grow equally well in the presence or absence of oxygen.

Example: Escherichia coli, Proteus marabilis, Salmonella typhi.

 LOCOMOTION:

Bacteria moves with the help of flagella that are attached to a wheel-like structure.

TAXIS

Directed movement in response to a stimulus is called taxis. Many motile bacteria are capable of taxis.

Phototactic: These bacteria are moving towards or away from the light.

Chemotactic: These bacteria are moving toward or away from some chemical.

Magnetotactic: These bacteria can detect earth’s magnetic field using tiny magnets composed
of iron particles present in their cytoplasm. Thus they can distinguish between up and down
direction.

 GROWTH:

Four distinct phases are recognized in bacterial growth curve:

 LAG PHASE: phase during which bacteria prepares themselves for division.

 LOG PHASE: phase during which bacteria grow and multiply very rapidy.
  Stationary Phase: bacterial multiplication is equal to death rate.

 Death/Decline Phase: Death rate is more rapid than multiplication.

 REPRODUCTION:

Reproduction of bacteria takes place by asexual and sexual methods.

ASEXUAL METHODS:

Bacteria reproduces asexually by the following methods:

1. Binary fission 2.Endospore formation

BINARY FISSION:

It is fastest mode of reproduction. Bacteria reproduce by binary fission when conditions are
favourable. The process of fission is very simple. It is completed in the following steps:

First the DNA is replicated into two chromatin

bodies.

Both chromatin bodies move apart into separate

nuclear regions.

Then a constriction appears around the middle of

the cell and it splits into 2 parts.

Both daughter bacteria grow in size, and form

mature bacterial cells. The whole process is
completed into 20-30 minutes.

ENDOSPORE FORMATION:

This mode of asexual reproduction takes place during unfavorable conditions. Main steps are
given below:

During this the whole protoplasmic content gets accumulated into a small area within the cell.

A cyst is formed around this mass it is called endospore.

This endospore is set free due to the decay of parental wall.

On the return of favourable conditions, this endospore enlarges to form mature bacterial cell.

Endospore is a method of survival of bacteria under unfavourable circumstances rather than a

method of reproduction.
GENETIC RECOMBINATION:
Genetic recombination is the formation of new genotype by resortment of gene following an exchange
of genetic material between two different chromosomes. Genetic recombination takes place by
following method.

1. CONJUGATION:
“In this process the genetic reproduction takes place between bacterial cells which are in direct
contact through a conjugation tube.”

Lederberg & Tatum discovered it in 1946 in Bacterial E. Coli.

2. TRANSDUCTION:
“In this method of genetic recombination and external agent such as (bacterio Phage Virus) transfer
bacterial gene from one bacterium donor to another bacterium (recipient).”
 Ladergerg and Zinder discovered this method of genetic recombination in 1952.

3. TRANSFORMATION
“In transformation a bacterium takes up foreign DNA from the surrounding environment, without
coming in contact with other bacterium or involving any third party.”

This process was discovered by Griffith in 1928 and further studied by Avery in 1944.

IMPORTANCE OF BACTERIA: Bacteria have both positive & negative importance. They play
 very important role in life of human being.

USEFUL ASPECTS:

1. DECAYING OF DEAD BODIES (DECOMPOSERS): Bacteria decomposes the dead remains of

plants and animals and human beings into simpler compounds. In this way they help to clean
the world.

2. ALIMENTARY CANAL BACTERIA: Certain bacteria are found in the alimentary canal of
herbivores and help them in the digestion of cellulose by enzyme “cellulase” .In human beings,
some bacteria are found to produce Vitamin K.

3. INDUSTRIAL BACTERIA: Many important industrial processes are accomplished by certain

bacteria. Important examples are given below:

 Curing and ripening of tobacco leaves

 Fermentation of tea leaves
 Ripening of cheese
 Retting of fibres
 Fermentation of sugar into alcohol
 Conversion of milk into curd
 Conversion of hides into skin

4. MEDICINAL BACTERIA:

 Valuable antibiotic drugs have been obtained from bacteria.

 Some bacteria are the manufacture of amino acids and proteins.

5. GENETICALLY ENGINEERED BACTERIA: Escherichia Coli has been programmed to make

following useful substances:

 Human growth hormone for the treatment of growth deficiencies.

 Insulin for diabetes mellitus.

6. FERTILITY OF SOIL: Bacteria increase the fertility of soil by adding organic substances due to
the decomposition of dead bodies.

7. NITROGEN FIXATION: Bacteria change nitrogen into its compounds like NO2 and NO3, this
process is called nitrogen fixation.

HARMFUL BACTERIA:

1. SPOILAGE OF FOOD: Bacteria spoil food substances by fermentation, putrification and

decomposition.

2. DISEASE IN MAN: Bacteria are responsible to cause various diseases in man and other animals,
such as tuberculosis (T.B), Pneumonia, Cholera, Typhoid, Tetanus, Diphtheria, Syphilis etc.

3. DISEASES IN PLANTS: Bacteria also cause disease in various plants such as citrus canker, fire
blight of apple, ring disease of potato, wilt of solanaceae plants etc.
CONTROL OF BACTERIA: The term control of pathogenic organisms refers to bringing the infection
in population to a tolerable limit.

Control of bacteria is essential for the prevention of disease and to avoid spoilage of food and
other industrial products.

IMPORTANT MEASURES:

Several measures are taken to control infectious microorganisms. Such measures involve the
following:

i. Treatment of infected individuals.

ii. Prophylactic treatment of population at risk through immunization & vaccination.

iii. Disruption of life cycle of pathogen at all possible stages.

iv. In case of epidemics, prevention of the spread of infection to non-infected individuals

through quarantine.

v. Identification & control or treatment of the reservoir hosts if any.

vi. Health awareness in masses primarily to reduce the risk factors related to some disease.

vii. Establishing a surveillance system.

viii. Killing of bacteria is brought about by a number of sterilization methods like exposing
bacteria to ultraviolent rays or to high temperature.

ix. Certain antiseptics, antibiotics and chemotherapeutic agents are used to kill the bacteria
present in a living tissue.

IMMUNIZATION AND VACCINATION

IMMUNIZATION:

“Immunization is the process of providing immunity artificially.”

This is achieved by injecting or administrating orally small amount of antigen anti bodies or immune
cells into the body. Its provide increased resistant against specific disease and may also help infected
person to fight the invading pathogen. Thus immunization may be protective or curative.

VACCINATION:

“It is a kind of Active immunization in which a small amount of antigen called Vaccine is introduced into
the body of a person by injection or by oral rout.”

 Vaccines are harmless inactive or weakened pathogen or their pathogenic derivative that
stimulate the immune system to mount defense against the actual pathogens.
 They stimulate the body to manufacture antibodies against the particular gen. vaccines are
mostly injected (e.g.) tetanus vaccine but some are taken orally e.g. Polio Vaccine.

ANTIBIOTICS:

Definition: “Antibiotics are the chemical substances which are used to kill microorganisms that
cause infectious diseases.”

Explanation:

These are produced by certain microorganisms and prevent the activity of other microorganisms.

The first antibiotic is Penicillium, which was isolated from Penicillium fungus in 1940.After that a
great work has been done in this field and many antibiotics have been isolated or synthesized for
the treatment of infectious diseases.

USE & MISUSE OF ANTIBIOTICS:

USES OF ANTIBIOTICS:

i. Some antibiotics have their effect against one bacterium and other are effective against
various bacteria i_e, they have widespread effect

ii. The antibiotics attack cell wall, plasma membrane, nuclear membrane & protein synthesis in
bacteria

iii. Antibiotics are also used in agriculture to kill different organisms. These are also used in animal
feeds to provide growth promoting substances

MISUSES OF ANTIBIOTICS:

i. By the extensive use of antibiotics more resistance is developed in pathogenic

microorganisms, after that they cause more infection in the body

ii. Antibiotics have many side effects, other organs of the body may be damaged

iii. Antibiotics may react with human metabolism and in severe cases death of person may occur

iv. Some antibiotics cause allergy in the body, such as penicillin

CYANOBACTERIA: They have been given different names like cyanophyceae, myxophyceae, blue
green algae and cyanobacteria. More than 150genera and 1500 species of cyanobacteria have
been discovered

STRUCTURE/SALIENT FEATURES:

 They are prokaryotic

 They are unicellular or may occur in colony form
 Cell wall is double layered
 Protoplasm is differentiated into outer coloured region chromoplasm and an inner
colourless region centroplasm
 Chromoplasm contains various pigments in which chlorophyll-a and phycocyanin are in
abundance imparting bluish green colour
 They are aquatic (fresh water with a few marine forms)
 Total absence of sexual reproduction
 Asexual reproduction takes place by means homogony, zoospores, akinetes and
 fragmentation

NOSTOC:

Nostoc is a typical example of cyanobacteria. It consists of 29 species

STRUCTURE:

 Nostoc is filamentous
 The filament are intermixed in a gelatinous masses forming a ball like structure called
coenobium
 It floats on water
 A single filament (trichome) looks like a chain of beads. Each filament
is unbranched and has a single row of rounded or oval cells
 Each cell has double layered wall. The outer thicker layer is made up
of cellulose mixed up with pectic compound. The inner thinner layer
is made up of cellulose
 The protoplasm is differentiated into an outer coloured region,
chromoplasm and an inner colourless region called centroplasm

 The chromoplasm is coloured due to the presence of various pigments

like chlorophyll-a, xanthophyll, carotene, phycocyanin and phyco-erythin

 These pigments are not located in plastids but inside an invaginated plasma membrane

 There is total absence of endoplasmic reticulum, mitochondria, golgi bodies and vacuole.
However ribosomes, pseudo vacuoles and reserve food in the form of cyanophyceae starch
are present

 The centroplasm, also called central body has hereditary material in diffused form, because
there is no nuclear membrane, nucleolus and typical chromosomes

HETEROCYST: At intervals there are found slightly larger oblong, colourless cells with slightly
thicker walls. These are called heterocyst. Each heterocyst is the center of nitrogen fixation. But
they are especially concerned in the multiplication of filaments during unfavorable conditions

NUTRITION: Nostoc is an autotroph like other blue-green Algae. It is also capable of fixing
atmospheric nitrogen and converts it into nitrates to make amino acids and proteins. This activity
takes place in heterocyst

REPRODUCTION: Sexual reproduction is absent in Nostoc but asexual reproduction takes place by
following methods

1. FRAGMENTATION:

When a Nostoc filament breaks into small pieces or fragments, they can grow to form full sized
filament.
2. HORMOGONIA:

During favourable conditions the filament generally breaks from the place where a heterocyst is
united with a vegetative cell. This position is then enveloped by mucilaginous layer and called the
hormogonium forms a new filament

3. AKINETES:

 These are formed between 2 heterocyst under unfavorable conditions

 Each akinete is somewhat oval in outline and is surrounded by a thick wall
 The wall is made up of “exospore”(outer wall) and “endospore”(inner wall)
 On approach of favourable conditions, its contents develop into a new filament by
repeated division

IMPORTANCE OF CYANOBACTERIA:

1. NITROGEN FIXATION: Many of them are able to fix nitrogen in atmosphere, hence they take
part in nitrogen fixation. Nostoc is used as nitrogen fertilizer in agriculture due to their high
nitrogen fixation ability

2. SOIL FERTILITY: They are grown in fields for improving soil fertility. Nostoc and Anabena are
used as nitrogen fertilizers in agriculture to improve soil fertility

3. HEALTHY ENVIRONMENT: During photosynthesis they use CO2 and H2O.They release O2 as a
byproduct. In this way they take part to change and flourish healthy environment

4. SOURCE OF FOOD: Many organisms of cyanobacteria are found in the form of phytoplanktons.
They are used as food by many aquatic animals

5. NEGATIVE IMPORTANCE: They also produce unpleasant smell in water and make it unable for
drinking.

CHAPTER: 7
KINGDOM PROTOCTISTA (PROTISTA)
INTRODUCTION:
Kingdom Protista also known as oldest group of eukaryotic mostly single celled organisms.
Mostly found in water.
Kingdom Protista includes microscopic unicellular and multicellular organisms. All Protista
organisms are eukaryotic organisms; they have true nucleus and other cell organelles. (Algae
and protozoans.)
Some contain chlorophyll and can make their food material e.g. Algae. Some lack chlorophyll
so they can't make food materiel. They live as parasites on other organisms and depend on
other organisms for food. E.g. protozoans. Parasitic protozoan organisms cause many
diseases in humans such as plasmodium cause malaria.

CLASSIFICATION OF KINGDOM PROTISTA:

KINGDOM PROTISTA IS DIVIDED INTO THREE GROUPS:
1. Algae (plant like protista)
2. Oomycota (fungi like protista)
3. Protozoa (animal like protista)

1: ALGAE (plant like protoctists)

Word Algae has been derived from latin word "Algin" meaning "sea weed" There are more
than 2000 species of algae. Algae are aquatic photosynthetic plants.
Algae may be unicellular i.e chlamydomonas,chlorella, or Algae may be multicellular ulva,
macrocystis. Algae live single or in colonial form. Most of algae contain different pigments
besides chlorophyll.

On the basis of different pigments algae have been classified into following groups.
1. Green algae (chlorophyta)
2. Brown algae (phaeophyta)
3. Red algae (rhodophyta)
4. Yellow green algae (xanthophyta)

Algae have thalloid (thallus like) body not differentiated into root, stem and leaves.
Algae lives as epiphytes (living on plants), Epizoic (living on animals), Saprophytes(living on
dead organic matter) or algae live as symbionts (in association with other organisms).

CHLORELLA: (Example of Algae)

It is fresh water, unicellular algae.
It is found floating on stagnant water of ponds pools or ditches.

Structure:
Chlorella is single celled (unicellular), rounded in shape and it lives singly.
It contains nucleus, mitochondria, Golgi body and chloroplasts.

Reproduction:
Chlorella reproduces only by asexual reproduction by aplanospores. Under normal conditions
cytoplasm (protoplast) of cell is divided into 8 or 16 non-motile spores called aplanospores.
At maturation cell wall ruptures. Aplanospores are liberated from parent cell and develop
into new cell.

Importance:
Chlorella is used in formation of an antibiotic "Chlorellin" which is used against bacterial
diseases. Chlorella is used as food, it contain 50% protein, 20%carbohydrates, 20%fats and
vitamins.

ULVA (algae):
Ulva is simple multicellular marine algae. Ulva is commonly called "sea lettuce”, it is found
attached to the rocky edges of coastal areas.
Plant body of ulva is called thallus, which is not differentiated into root, stem and leaves but
it is elongated wrinkled blade of about 30cm.
The thallus (plant body) is very thin only two cells in thickness, which is spread over rocks as
green carpet. It is attached to the rocks and other objects by hold fast which is long thread
like structure of cell present at lower side of thallus.

TYPES OF THALLUS :( plant body)

Thallus (plant body) of ulva is of two types
1. Sporophyte.
2. Gametophyte.
Sporophyte and Gametophyte are similar in Structure and
appearance (Morphology).

Sporophyte:
Sporophyte thallus has diploid (2n) 26 chromosomes.
Sporophyte reproduces by asexual reproduction by producing
spores.

Gametophyte:
Gametophyte thallus has haploid (n) 13 chromosomes
Gametophyte reproduces by sexual reproduction by producing
Gametes.

REPRODUCTION IN ULVA:
Reproduction in ulna takes place by asexual and sexual methods.

Asexual method:
Asexual reproduction takes place in diploid sporophyte having (2n) 26 chromosomes. All cells
except basal cells of thallus (plant body) produce haploid quadric flagellate zoospores (motile
spores) by meiosis.
These haploid (n) zoospores are detached or liberated from plant body incoming tides. These
haploid zoospores after swimming and rest lose their flagella and grow into haploid (n)
gametophyte ulva (having 13 chromosomes).

Sexual Reproduction:
Sexual reproduction takes place in gametophyte, which is haploid having (n) 13
chromosomes. Gametophyte produces biflagellate haploid gametes with 13 chromosomes.
Gametes are similar in structure so they are called “isogametes”. Gametes are smaller than
zoospores.
Two gametes of different plants fuse together and form a quadri-flagellated diploid
zygote.This zygote after a period of swimming and rest loses its flagella and grow into a
diploid (2n) sporophyte ulva.

ALTERNATION OF GENERATION IN ULVA:

Ulva shows isomorphic (same in structure) alternation of generation. Alternation of
generation is a process in which diploid sporophyte generation gives rise to haploid
gametophyte generation, which in turn gives rise to sporophyte.
This alternation of sporophyte to gametophyte and again gametophyte to sporophyte is
called alternation of generation.

2. OOMYCOTA (fungi like protoctista):

Organisms in this group resemble with fungi in few characters as they don’t posses
chlorophyll like fungi body is composed of thread like structure called “hyphae” as fungi.
Some of them also have centrioles and cell wall. Kingdom Protoctista have two major groups,
which are fungi like
1. Slime mold (plasmodium)
2. Water mold (phytophthora infestans)

1. SLIME MOLD: (Plasmodium)

Slime mold are creeping multi nucleate of cytoplasm (Living substance). Look like egg white.
It can crawl over grass and trees,
It grows at moist places, wood, soil and decaying vegetation where it finds food and
moisture.

Body Structure:

Vegetative plant body of slime molds consists of irregular thin slimy mass of naked
protoplasm which has no outer proper wall; thin slimy layer bound the protoplasm.
The body of slime mold is called “plasmodium”; it has no proper shape because it continues
to change its shape.
Cytoplasm contains food vacuoles, undigested food particles and many nuclei. Cytoplasm is
differentiated into two regions. Outer ectoplasm or hyaloplasm, which is transparent.
Inner endoplasm, which is granular and contain many nuclei and vacuoles and some times
different colours like orange, red, brown or violet. Chlorophyll is absent in cytoplasm.

Movement:
Slime mold has no proper locomotory organs.
It moves with the help of pseudopodia like amoeba.

Reproduction:
Takes place by sexual and asexual methods.

1. ASEXUAL REPRODUCTION:(fructification sporangia)

During dry or warm weather the plasmodium changes into cluster of ball like fruiting bodies
called sporangia.
Sporangia produce large number of microscopic asexual reproductive cells called spores by
meiosis.
Each spore is uninucleate haploid and thick walled.
Spores are liberated by wind or water to other places.
In suitable condition spores germinates into one or more swarm cells (flagellate).
The spore germinates into my amoeba cells (non flagellate).
These spores take part in sexual reproduction.

2. SEXUAL REPRODUCTION:
Haploid swarm cells or myxameoba act as gametes and fuse together and a diploid zygote is
formed which ultimately develops into new a plasmodium.

2. PHYTOPTHERA INFESTANS (Fungi like proctists)

It is an e.g of water molds (about 200 species are aquatic and live on fishes as parasites)
Phytophthora infestans is a pathogenic fungus, which cause late blight of potato and tuber
rot of potato. These diseases were first observed in EUROPE and AMERICA in 1830s.

Body Structure:
Body of phytophthora is called mycelium, which is composed of many thread like structure
called hyphae.
Hyphae are aseptate, (no septum), coenocytic (contain many nuclei), Hyaline (thin,
translucent) branched and nodulated.
Hyphae have special organs, haustoria for absorption of food from host by penetrating.

Nutrition:
Phytophtora infestans is a parasitic organism, which get its food from other organisms (from
plants or animal).

Reproduction:
Reproduction takes place by asexual or sexual methods.

1. ASEXUAL REPRODUCTION:
 In favourable condition many erect branches arise from the mycelium these branches
are called SPORANGIOPHORES.
 Sporangiophores produces sporangia in which biflagellate
 Zoospores are produced.
 On maturation sporangium bursts and zoospores are liberated and come out.
 Zoospores become encysted if conditions are not suitable.
 Other wise each zoospore develops into new hyphae.
 Optimum Temperature for production of sporangia is 3ºC to 22ºC, 100% humidity is
required.

2. SEXUAL REPRODUCTION:
 Sexual reproduction takes place by male and female sex organs, which may develop
on same hyphae or on different hyphae.
 Male sex organ is antheridium and female sex organ is oogonium, both contain many
nuclei.
 Fertilization takes place between antheridium and oogonium.
 Oogonium wall is dissolve at point of attachment. Antheridial nucleus is shifted to
oogonium.
 Male and female nuclei are fused together and zygote or oospore is formed.
 Oospore germinates a germ tube; sporangium develops at the tip of germ tube in
which many spores are produced.
 In favorable conditions Spores germinate into new hyphae.

ECONOMIC IMPORTANCE OF PHYTOPHOTHORA:

Phytophthora causes disease late blight potato and tomato, which
damages the crop. It attacks under ground and aerial parts of plant body.
Due to disease black or brown spots are produced on skin of potato and leaves.
Which increases in size and tissues become very soft and become blighted.
3. PROTOZOA (Animal like protoctists):
Word “Protozoa” is derived from GREEK word “protos” and “zoan” means First
animals”.
 Protozoans are unicellular, microscopic organisms.
 Protozoans are rounded oval, elongated or irregular in shapes.
 They have true nucleus (eukaryotic).
 The protoplasm in some organisms is divided into outer ectoplasm and inner
endoplasm.
 They live singly or in a colony form.
 Protozoans are mainly aquatic (live in water).
 Protozoans live as parasites in body of animal and plants and cause many diseases.
 Respiration takes place through external surface of body or by diffusion.
 Reproduction takes place through by simple cell division or by sexual reproduction.
 Movement takes place by pseudopodia, cilia or flagella.
 On the basis of locomotion protozoans are divided into following classes
1 .CLASS FLAGELLATA (mastigophora)
2 .CLASS SARCODINA (rhizopoda)
3 .CLASS CILIATA (ciliophora)
4. CLASS SUCTORIA
5. CLASS SPOROZOA

1. CLASS FLAGELLATA:
 Organisms of this class have one or more flagella for locomotion.
 Many organisms of this class possess chlorophyll so they can prepare their food.
 They live in water e.g. euglena, volvox, (chlorophyllus).
 Many species do not contain chlorophyll they are usually parasites.
 Parasites live in body of humans and cause diseases

Example : trypanosoma causes trypanosomiasis (African sleeping sickness).

Leis mania causes leishmaniasis (skin diseases).

2.CLASS SARCODINA:
 Protoplasm is divided into ectoplasm and endoplasm.
 They keep changing their shape.
 They have no specific organs for locomotion.
 They use pseudopodia or false feet for locomotion and to get food particles.
 Pseudopodia are cytoplasmic extensions.
  They reproduce by binary fission (asexual method).
 They are aquatic, come are parasites and pathogenic for human beings.
 Entamoeba histolytic causes ameobic dysentery in humans.

Example : Amoeba , Entamoeba gingivalis , Entamoeba histolytica.

3. CLASS CILIATES:
 Organisms of this class have fine hair like structures called CILIA on their body.
 Cilia are used for locomotion and for food collection.
 They contain two nuclei macro nuclei and micronucleus in their body.
 They reproduce by binary fission (asexual) and by conjugation (sexual).
 Most of them are free living in water.
 Only one specie is parasite, which cause bloody diarrhea in humans (Balantidum coli).

Example: Paramecium ,Vorticella , opalina etc

4. CLASS SUCTORIA:
 These protozoans are closely related to ciliates because having cilia and macro and
micronucleus.
 Young suctorians have cilia, but adults are without cilia.
 They are attached to substratum by a long rod like stalk.
 They have groups of tentacles on their body.
 Tentacles are knob like and pointed which help in capturing the prey.
 Tentacles secrete a poisonous substance to paralyse their prey.
 Reproduction takes place by budding.

Example: Acineta tuberosa.

5.CLASS SPOROZOA:
 The sporozoans are mostly parasites.
 They have not any special organ for locomotion.
 They live as intracellular parasites, get their nutrients from the host.
 They cause serious disease in humans and animal.
 Malaria is most common disease of human, which is caused by sporoszoan
Plasmodium.
 Reproduction takes place by sexual and asexual method.
 Example:. Plasmodium, Monocystis, Toxoplasma.

PLASMODIUM (Malarial parasite) LIFE CYCLE:

GRASSI first studied life cycle of MALARIAL PARASITE IN 1808.
Plasmodium completes its life cycle in two hosts.
Man (primary host) and female Anopheles mosquito (secondary host).
Parasite completes its life cycle in two phases: a) Asexual life cycle in man b) Sexual life cycle
in mosquito.
1. ASEXUAL CYCLE IN MAN: (schizogony)
A healthy person acquires infection when a female Anopheles mosquito, containing
infective stages (sporozoites) of the parasite in its salivary gland, bites him for sucking his
blood. The life cycle completes in man in 4 phases.

1. PRE-ERYTHROCYTIC PHASE: (before entering RBC)

 Within the human blood, the sporozoites invade the hepatic cells within one hour.
 After growing for a number of days it becomes a schizont.
 It divides to form a number of uninucleate Exoerythrocytic merozoits. These are
liberated when the liver cells bursts. It may invade fresh liver cells and multiply
producing many generations. This phase is referred to as Pre- Erythrocyte phase.

2. ERYTHROCYTIC PHASE: (entering in RBC)

 Merozoites transferred from liver cell to blood and enter in the red blood corpuscles
(RBC).
 Merozoites change its shape in RBC and now called trophozoites, which uses
hemoglobin of RBC as food and multiply within RBC by schizogony (simple cell
division).
 When trophozoites increase in size, the nucleus is shift to one side into the
peripheral cytoplasm, it resembles a signet ring and is referred to as signet ring stage.
 The blood hemoglobin is broken down into its protein components which is used by
trophozoite which develops into an active amoeboid trophozoite.
  After active feeding, it becomes a schizont. It undergoes schizogony and produces
Erythrocyte (E) merozoites.
 With the rupture of RBC’s the erythrocyte merozoite along with malarial pigment are
liberated into blood plasma. These invade fresh corpuscles to repeat the cycle.

3. GAMETOCYTOGENESIS:
 After few erythrocytic generations, erythrocytic merozoites invade the RBC’s and
increase in size to become either microgametocyte (male) or macrogametocyte
(female)
 They do not divide but remain in their host corpuscles until they are ingested by
vendors.

2. SEXUAL CYCLE IN FEMALE ANOPHELES MOSQUITO:

1. GAMETOGONY: (formation of gametes)
 Mosquito takes up Gametocytes from malarial patient by biting into the stomach of
mosquito.
 Microgamete produce male gametes and macrogametes develop into female
gamete or oocyte.

2. SYNGAMY: (fertilization or fusion of gametes)

 Male and female gametes fuse together it is called “syngamy”. The zygote becomes
worm-like ookinete and zygote or oocyte is formed in stomach of mosquito.

3. SPOROGONY: (formation of sprozoites)

 After 6-7 days nucleus of oocyst is divided into thousands of sporozoites by process
of sporogony.
These spores migrate in saliva of mosquito and again transferred to human blood by
mosquito bite.
SYMPTOMS OF MALARIA:
Patient feels severe chill, headache, and muscular pain.
Body temperature rise to 106 º F.
Heartbeat is increased.
Onset of malaria fever patient begins to sweat and shivering starts.
Patient feels weakness.

TREATMENT OF MALARIA:
Antimalarial drugs like “quinine” and “chloroquine” should be used for treatment of malaria.
Treatment should be done properly.

TYPES OF PLASMODUIM:
1. Plasmodium Vivax
2. Plasmodium Falciparum
3. Plasmodium Malariae
4. Plasmodium Ovale
 CHAPTER 8: KINGDOM FUNGI
INTRODUCTION OF FUNGI:
i. Fungi are non chlorophyllous unicellular organisms. Fungi are Heterotrophic (they cannot
make their food material) as they lack chlorophyll.
ii. Fungi are generally found in moist and shady places.
iii. Body of fungi is mycelium which is thallus like which is not differentiated into root, stem and
leaves. Mycelium is composed of Long Branch like filaments called Hyphae.
iv. Fungi live as parasites (get their food from non living organisms) or live as saprophytes (get
their food from dead organic matter).
v. Parasitic fungi cause many diseases in plants, and humans.
vi. Some fungi are decomposers along with bacteria and increase soil fertility.
vii. Fungi resemble with plants having cell wall and they lack centrioles in their cells.
viii. Cell wall of fungi is composed of chitin.
ix. Some fungi are edible (mushrooms), some are poisonous and dangerous.

STRUCTURE OF BODY OF FUNGI:

Body of fungi is called ‘mycelium” which is composed of long slender branched tubular
thread like filaments called “hyphae” (singular hypha Gr:Hyphe=web)
Hyphae collectively form mycelium. Hyphae may be septate or non septate.

i. SEPTATE HYPHAE:
 Such hyphae are divided by cross walls called septa into individual cells.
 Cells contain one or more nuclei.

ii. NON SEPTATE OR COENCYTIC HYPHAE:

 Such hyphae is not divided into cells because septa are absent.
 It form elongated multinucleate large cells.
 The cell wall of fungi is composed of chitin the cells of mycelium are filled with color cytoplasm.
Which contain nuclei and vacuoles.

NUTRITION:
 Fungi are non chlorophyllus so they are heterotrophic in mode of nutrition.
On the basis of nutrition fungi are classified into following types.

1. SAPROPHYTIC FUNGI or DECOMPOSERS:

Those fungi, which get their food from dead organic, matter by decomposing organic matter.
Saprophytic fungi get their food from substratum by the help of rhizoid root like structures.

2. PARASITIC FUNGI:
 They depend on living plants or animals for their food. They cause many diseases in plants
animals and human. Parasitic fungi absorb their food from other organisms with the help of
haustoria.
 Some parasitic fungi can only grow on living host they are called OBLIGATE PARASITES.
 Some parasitic fungi can grow on artificial media as well as living host they are called
FACULTATIVE PARASITES.
 Some fungi are predator fungi. They obtain their food from animals Nematodes (round worms,
ascaris, filarial)).

3. SYMBIOTIC FUNGI:
 Some fungi live in association with other organisms on mutual benefits basis. These fungi are
called SYMBIOTIC FUNGI.
 Some fungi live in association with algae are called LICHEN.
 Some fungi in association with roots of leguminous plants are called Mycorrhizae.

i. Lichens:
 Lichens are association between fungi and certain algae (blue green algae or green algae).
 Fungi and algae live together and get benefit from each other. Fungi absorb water and salt and
supply to algae while algae manufacture food and provide to fungi. Lichens can grow on rocks,
tree, trunk, roofs and soil surface.
 Body of lichens is thallus like, it is flat and branched lichens are of different size and colours
such as green, brown, yellowish green and some times black.
 Example Crusotse, Foliose, Basidiolichen.

ii. Micorrhizae:
 Mycorrhizae (Singular Mycorrhiza) are symbiotic association between fungi and plant roots.
 Fungi and root both get benefit from each other. The fungus mycelium surrounds the root
and some times penetrate into roots.
 The fungus absorbs nutrients like phosphorus, zinc and water from the soil and pass these
nutrients to plant root.
 In return plants provide sugars and food substances to the fungi.

 Endomycorrhizae:
Some fungi penetrate into root cells this is called ENDOMYCORRHIZAE.

 Ectomycorrhizae:
Some fungi remain at surface of the roots and do not penetrate into cells this is called
ECTOMYCORRHIZAE.

REPRODUCTION:
In fungi reproduction takes place by asexual and sexual methods.
1. Asexual Reproduction:
Asexual reproduction takes place by following methods.

i. Fragmentation.
ii. Budding
iii. Spore Formation
iv. Conidia Formation

i. FRAGMENTION:
In this process mycelium breaks into many small pieces and each piece develops into new
fungus.
ii. BUDDING:
In unicellular fungi like yeast small tiny out growth or bud is produced which separate from
parent cell and grow into a new fungus.

iii. SPORE FORMATION:

 In this type of reproduction small, haploid and non-motile spores are produced in
reproductive organs called sporangia.
 These spores are produced in large number and dispersed by wind water or insects to other
places and germinate into new fungi e.g. Zoospores chlamydospores.

iv. CONIDIA FORMATION:

 Conidia are also non-motile haploid spores, which are not produced inside the sporangia, but
conidia are formed in chain like structures on the branches called CONIDIOPHORES.
 Conidia are dispersed by wind to other places and germinate into new fungus.

2. Sexual Reproduction:

GAMETANGIAL COPULATION or CONJUGATION:

 Sexual reproduction in fungi takes place by fusion of two morphologically different or similar
gametes or gamentagia that produce zygote (oospores).
 These gametes are produced in differed structures called antheridia (Male organ) and
oongonia (female organ).
 Sexual gametangial copulation (conjugation) occurs in three phases.

i.PLASMOGAMY ii.KARYOGAMY iii.MEIOSIS

i.Plasmogamy:
When two gametes or gametangia come in contact, the cytoplasm (Protoplast) of two gametes
fuse together this is called PLASMOGAMY.

ii.Karyogamy:
Fusion of two nuclei after fusion of cytoplasm (plasmogamy) is called KARYOGAMY. By which
diploid zygote or oospore is formed.

iii.Meiosis:
Meiosis occurs in zygote and fungi produce different types of sexual haploid such as
basidiospores and ascospores.
ECONOMIC IMPORTANCE OF FUNGI:
Economically fungi is very important.
Fungi are useful as well as harmful for humans as follows.

1. USEFUL FUNGI:
FOOD:
 Many mushrooms are used as food and cultivated in various countries of the world.
 Yeast fungi are used in bakeries for making bread, bear and wine.
 Yeast contain about 50% proteins and vitamins B complex.
 Penicillium is used in cheese industry.

MEDICINE:
Many antibiotics like penicillin, chloromycin, neomycin, tetracycline ergotine, and citrine are
obtained from fungi and used against various bacterial and fungal diseases.

SOIL FERTILITY:
Fungi increase soil fertility by decomposing dead organic matter.Some fungi also fix
atmospheric nitrogen inform of nitrates in soil. These nitrates are used by plants for protein
formation.

HARMFUL FUNGI:
HUMAN DISEASES:
 Many fungi produces, many diseases in haumans.
 Athelete’s foot and ringworms are super ficial fungal infection caused by trichophyton
fungus.
 Histoplasmosis is lung infection caused by fungi spores which are inhaled with air
present in birds faeces, if infection spreads it can kill the patient (death can occurs).
 Moniliasis is disease of skin, mouth and vaginal thrash caused by a yeast Candia
albicans.
 Aflatoxin produced by flavus contaminate milk, eggs, meat, peanut and corn and cause
cancer in humans.
 Ergotism is a disease, which causes nervous spasm convulsion even gangrene this
disease is caused by bread from (parole ergot flour) Claviceps fungus.

PLANT DISEASES:
 Parasitic fungi cause various diseases in plants as follows
 Rusts and smuts of wheat, corn and rice caused by Puccinia and Ustilago destroy these
crops.
 Powdery mildews of grapes, rose, wheat, pea, chili, and spinach caused by Peronospora.
 Apple scab is caused by Venturia.
 Red rot of sugar cane ,root of cotton caused by Colletotrichum.
 Fungi also cause wilt of potatoes, plums apricot and peaches.

FOODSPOILAGE:
Many fungi like MUCOR, RHIZOPUS, ASPERGILLUS, PENICULLIUM grow on food stuff and
produced Mycotoxin(Poisonus substances) and make food dangerous for humans.

SPOILAGE OF LEATHER AND PAPER GOODS:

Many fungi spoil leather goods such as suitcases, shoes, bags, wool, books, timber, cotton etc.

POISONOUS MUSHROOMS:
Many mushrooms are poisonous and cause death e.g toadstools and death stools.

CLASSIFICATION OF FUNGI

There are four divisions of fungi

1. ZYGOMYCOTA (phycomycetes)
2. ASCOMYCOTA (Ascomycetes)
3. BASIDOMYCOTA (basidiomytes)
4. DEUTERIOMYCOTA (fungi imperfecti)

1. ZYGOMYCOTA (Phycomycetes):
 During their sexual reproduction they produce zygote or zygospore so they are called
zygomycota.
 It is smallest group of fungi includes about 600 species it is primitive group of lower
fungi. They are opportunistic parasite.
 In this group bread mold (Rhizopus) and other saprophytic fungi are included.
 They occur in both aquatic and terrestrial habitat as parasite or saprophytes.
Example: Mucor, Rhizopus, albugo.

Structure:
These fungi have coenocytic mycelium i.e. it is multinucleate and unseptate.
Mycelium contain various sporangia, which take part in asexual reproduction.

Reproduction:
Reproduction takes place by asexual and sexual methods.

i. ASEXUAL REPRODUCTION:
By Spore Formation:
 Asexual reproduction takes place by haploid spores. Spores are produced in rounded
bodies Sporangia. Which are produced on special branches sporangiophores.
 When spores become mature walls of sporangium ruptures and spores are liberated out.
 When spore find suitable condition they germinate into new fungi.

ii. SEXUAL REPRODUCTION:

 Sexual reproduction takes place by gametangial copulation or conjugation (Fusion of
gametangia) or by fusion of hyphae.
 Two different gametangia, which are produced on same mycelium or produced on different
mycelia, come in contact and fuse together.
 Plasmogamy (fusion of protoplasm) occurs and which is followed by karyogamy (fusion of
nucleus) between two different gametengia.
 As a result diploid (2n) zygote is formed which is called zygospore. Meiosis occur in cells of
zyospores.
  Zygospore germinates into hyphae with sporangia. Sporangia produces many spores, after
maturation sporangium wall ruptures and spores liberate out and each spore germinates in
fungus.

2. ASCOMYCOTA (Ascomycetes or Sac fungi):

 It is a large group of advance fungi of about 6000 species. During sexual reproduction they
produce ascospores in sac like structures called “ASCUS” or “ASCI” so they are called sac
fungi.
 Ascomycota includes yeast, molds, morels (have mushrooms like fruiting body) and truffles
(used as food, structure like shorvele, blackened apple).
 Many ascomycetes are serious plant pathogens and cause powdery mildews, leaf curl of
peach, apple scab and wheat rusts.
E.g. penicillium, yeast, aspergillus.

Structure:
Body is called, mycellium composed of many hyphae.
Mycellium is branched and septate multi nucleate or uninucleate.
Unicellular yeast are also found.

Reproduction:
Reproduction takes place by
1.Asexual Reproduction 2.Sexual Reproduction
 1.Asexual Reproduction:
Asexual reproduction takes place by fission budding and conidia formation.
Most common method of asexual reproduction is conidia formation.
Conidia Formation:
Conidia are asexual spores produced on special branches called conidiophores.
These conidia are dispersed at different places and during favourable condition conidia
develop into new fungi.

2.Sexual Reproduction:
 In ascomycetes sexual reproduction takes place by male and female reproductive organs.
 The male organs are called antheridia and female organ are called ascogonia.
 Male nuclei from antheridia transfer into ascogonia through beak like growth called
trichogyne.
 Plasmogamy (fusion of cytoplasm) occurs and dikaryotic (having two nuclei) heterokaryotic
(having different nuclei) septate hyphae arises at the point of fusion.
 This hyphae from special fruiting bodies called ascocarps.In these ascoscarps, asci or ascus is
formed.
 In each ascus two nuclei of male and female fuse and form a diploid zygote.
 Zygote divides by meiosis and forms 4 haploid nuclei.
 These 4 haploid nuclei again divide by mitosis and form 8 haploid nuclei.
 These nuclei become walled and changed into ascospores, within ascus.
 At maturity ascus brusts and ascospores are liberated and each ascospores into new fungi.

TYPES OF ASCOCARPS:
There are 3 types of ascocarp (fruiting bodies)
in which ascospores are produced.
1.Apothecium:
iIt is cup shaped or disc shaped ascocarp.
Its cavity is lined with a single row of asci (ascus).

2.Perithecium:
It is flask shaped ascocarp .At the apex of parithecium a pore
or opening is present called ostiole.

3.Cliestothecium: It is rounded or completely closed

ascocarps.

YEAST: (e.g of ascomycota)

 Yeast is unicellular fungus.
 Yeast may be oval, rounded or shaped.
 Yeast are economically important and they are used in formation of
wine, bear, and bakery products and in fermentation of alcohol.
 Yeast is also responsible for causing many diseases in human and
they spoil food stuff
 Reproduction:
Reproduction in yeast takes place by asexual reproduction and sexual reproduction.
1.Asexual reproduction takes place by fission or budding.
2.Sexual reproduction takes place by conjugating or fusion of two cells of yeast.
Zygote is formed which works as ascus in which ascospores are produced, on maturation
ascospores liberated and grow into new new yeast cells.

IMPORTANCE OF YEAST:
Yeast has positive as well as negative importance.

POSITIVE IMPORTANCE:
 Yeast is used process to prepare different bakery items in fermentation.
 It is also used in the formation of alcohol.
NEGATIVE IMPORTANCE:
 It destroys different food substances.
 It causes damage to butter and cheese.
 It may cause diseases of nails, skin and hairs in man known as moniliasis.
 It may cause lung disease.

3. BASIDOMYCOTA (basidioycetes):
 It is advances group of fungi with about 16000 species.
 Basidiomycetes are named for their characteristic sexual reproductive structure the
basidium in which basidiospores are produced.
 In this class both parasites and saprophytes fungi are included many are important
plant pathogens (rust and smuts).
 Many mushrooms are used as food but others are deadly poisonous (puffballs, toads,
stools, jelly and shelf fungi are included)
E.g. Puccinia, Ustilago, Agaricus.
Structure:
The mycelium of Basidiomycetes is branched and septate.
Mycelium may be with uninucleate cells called primary or monokaryotic mycelium.
Mycelium may be with two nuclei called secondry or dikaryotic mycelium.

Reproduction:
Reproduction takes place by both asexual and sexual reproduction.

1.ASEXUAL REPRODUCTION:
Asexual reproduction is rare in moist basidomycetes,while in others asexual reproduction
takes place by oidia or spore formation.
Oidia:
In some cases the hyphae undergo segmentation rounded off and forms oidia or
ARTHROSPORES, each arthrspore germinate into a new fungi.

2.SEXUAL REPRODUCTION:
 There are no sex organs present on mycelium.
 This process occurs by the contact of two different monokaryotic or primary hyphae
(having one nucleus).
 With the fusion of two different monokaryotic or primary mycelium a dikaryotic
(having two nuclei) mycelium or secondary heterokaryotic mycelium is produced.
 The dikaryotic mycelium produce spores called chlamydospores or tueletspores with 2
haploid nuclei..
 The two haploid nuclei of chlamydospores fuse together karyogamy occurs and diploid
nucleus is formed. This develops into a tube like structure called basidia; this basidium
divided into four cells. (Basidia are produced in fruiting bodies called basidicarp).
 The diploid nucleus divide into four nuclei; each migrates into cell of basidium and
form four basidiospore.
 After maturation the basidiospore separate from basidium and germinate into new
fungus.
 Fruiting body or basidiocarp is mushroom complex body in which basidia are formed (
In basidia Basidiospores are produced).
4.DEUTROMYCOTA: (fungi imperfecti)
 There are about 17000 species of fungi imperfecti
 It is an artificial group of fungi.
 In this group all those are included in which sexual reproduction is absent or not
observed or replaced by other mechanism such as genetic recombination. (Para
sexuality)
 In this group mostly fungi of ascomycetes and basidomycetes are included.
 Most of fungi of this group are saprophytes and parasite.
 Parasitic fungi of this group cause disease, in humans and plants.
 E.g. ringworm, athlete’s foot, in man.
 Rust and smuts in plants of light blight potato, wilt disease of tomato, cotton melon,
pea banana, and potato etc.
 From penicillum well known antibiotic penicillin is obtained.
 From aspergilus citric acid is obtained.

Reproduction:
1. ASEXUAL REPRODUCTION: Takes place by oidia or spore formation.
2. SEXUAL REPRODUCTION: is absent while genetic recombination or Para sexuality occurs.

Para sexuality:
Due to the absence of sexual reproduction fungi imperfecti show special kind of genetic
recombination called para sexuality. In this process two genetically different hyphae fuse
together and exchange portions of chromosomes, due to this exchange new hyphae arises
with genetic recombination cells and become pathogen for plants.

1. ZYGOSPORES:
In zygomycota during their sexual reproduction zygote is formed by fusion of gamentagia or
different hyphae. This zygote is called zygospores. Which give rise to new hyphae.

2. ASCOCARP / ASCI:
Fruiting body of all ascomycete’s fungi, which bears sac like structures called ASCI.
Asci (singular ascus) are oval or tubular sac like structure inside ascocarp; which produce
ascocarp by sexual reproduction.

3.BASIDIOCARP / BASIDIA:
Mushroom like fruiting body of basidomycetes fungi, which bears club shaped basidia.
Basidia (singular basidium) club shaped cells, which produce basidiospores by sexual
reproduction.
 CHAPTER 09: THE KINGDOM PLANTAE

PLANTS:
DEFINITION:
"Plants are multicellular eukaryotes that are photosynthetic autotrophs where the
zygote develops into an embryo."
All the plants have a life cycle that shows an alternation mode of generations, some
have a dominant gametophyte and some have a dominant sporophyte.
AN OUTLINE OF CLASSIFICATION OF PLANTAE:

DIVISION - I: BRYOPHYTA (Non-vascular plants) :

i. Class Hepaticae (liver worts)
ii. Class Musci (Mosses)
iii. Class Anthocerotae (Horn worts)

DIVISION - II: TRACHEOPHYTA (Vascular plants) :

i. Subdivision Psilopsida (Psilopsids)
ii. Subdivision Lycopsida (Club mosses)
iii. Subdivision Sphenopsida (Horse tails)
iv. Subdivision Pteropsida (Ferns)
v. Subdivision Spermopsida (Seed plants)

BRYOPHYTES:
The word ‘bryophyta’ is derived from two words. In Greek Bryon means moss and phyta
means plants. Hence moss and moss like plants are included in this group. They are non-
vascular plants and liver worts, horn worts and mosses are included in this group.

GENERAL CHARACTERISTICS AND AMPHIBIOUS NATURE:

The general characteristics of this group of plants are as follows.

i. HABITAT:
It is the first successful group of plants to adopt the land habitat, but they have still link with
the water to some extent. These plants are found in moist, humid and damp places. They are
mostly seen in rainy forest and hill areas.

ii. STRUCTURE:
They are very primitive type of plants, their body is called thallus i.e., it cannot be
differentiated into root, stem and leaf. They are non-vascular plants hence vascular bundle is
absent. True root is absent in bryophytes, but hair like structure arise from the lower part of
a plant called rhizoids. They help in the attachment of a plant body to the soil as well as in the
absorption of water.

iii. SIZE RANGE:

 These plants are very small in size as they can’t bear high intensity of light and due to the
absence of vascular tissues for the conduction of food and water to different parts. Most are
only 1-2 cm in height and even the largest are usually less than 20 cm tall.

iv. GROWTH STYLE:

Bryophytes are primitive land plants believed to be migrated from water and still need high
moisture for normal growth. Bryophytes locked the lignin fortified tissues required to support
tall land plants. Although they may sprawl horizontally as mats over a large surface,
bryophytes always have a low profile.

v. NUTRITION:
Bryophytes are green plants due to the presence of special colour pigment called
‘chlorophyll’. It captures small intensity of light and absorb CO2 through tissue gaps which
helps in the manufacturing of their own food material hence they are called autotrophs.

ALTERNATION OF GENERATION:
The life cycle shows heteromorphic alternation of generation. The life cycle is completed into
two stages.

Gametophyte Stage:
It is the first and dominant phase of life cycle. In this phase male and female
reproductive organs are produced, antheridia (male) and archegonia (female).

The Antheridia:
The antheridia are club shaped. Each antheridium is surrounded by an outer jacket layer.
Inside the antheridium antherozoid mother cells are produced. They divide and redivide to
form motile biflagellated antherozoids male gametes.

The Archegonia:
Each archegonium is flask shaped. It consists of three parts called stalk, venter and neck.
The stalk helps in the attachment of archegonium. Venter is the middle swollen part.
It contains a large egg cell and smaller venter canal cells. Neck is the upper elongated tube
like part. It contains neck canal cells.

 Fertilization:
 The motile antherozoids move towards archegonium in the presence of water. They enter
the archegonium through its open mouth and one antherozoid fuses with egg cell, with the
result zygote (2n) is formed.

i. Sporophytic Stage:
The zygote develops into sporophyte. The venter wall enlarges to form a protective layer
around the embryo, called calyptra. The sporophyte grows upon gametophyte; it depends
partially or completely upon the tissues of gametophyte.

PARTS OF SPOROPHYTE:
The sporophyte consists of three parts foot, seta and capsule.
 Foot:
Foot helps in the attachment of sporophyte and in the absorption of food from the tissues of
gametophyte.
 Seta:
The seta is a stalk of capsule. It provides support to the capsule.

 Capsule: The capsule produces spore mother cells. They are diploid (2n). They divide by meiosis
and form haploid (n) spores. Each spore can germinate into a new a new gametophyte during
favourable conditions.

PLANTS BECOME ADAPTED TO LAND

Historical Background:
It is the opinion of all biologists that the land plants and animals have been evolved
from aquatic living organisms. On land they got their control after a difficult and long period.
When the plants migrated from water to land, they faced certain problems. The most
important are as follows.

i. To obtain and conserve water.

ii. To absorb CO2 from atmosphere for photosynthesis.
iii. To solve these problems the plants change their structure according to the environment. First
of all they shifted from aquatic to amphibious habitat then they started their life on dry land.
Amphibious are the plants which grow on moist or live both in dry as well as wet places.

Adaptive Characteristics:
The characteristics of plants which are migrated from wet to dry places are as follows.
i. Productive of rhizoids for water absorption
ii. Conservation of water
iii. Absorption of CO2
iv. Hetrogamy
v. Protection of reproductive cells
vi. Formation of embryo

i. PRODUCTION OF RHIZOIDS FOR ABSORPTION OF WATER:

Rhizoids are the thread or hair like structures which arise from the lower region of the plant.
They greatly increase the surface area for the absorption of water from the soil. E.g.
Marchantia, Moss etc.
ii. CONSERVATION OF WATER:
In land plants conservation of water is very important. In Liver worts and Mosses the plant
body is called thallus which is multilayered. The thallus is composed of numerous cells but
only few cells are exposed to the sunlight on the outer layer. The thallus also contains cuticle
made up of a waxy substance called ‘cutin’. It prevents the evaporation of water. The cuticle
is also formed in higher land plants.

ABSORPTION OF CO2:
The land plants possess a special system for exchange of gases. Marchantia plant contains air
chambers in the thallus which open to the outside by air spores. The chambers have green
filaments which perform the function of photosynthesis. The CO2 of water is diffused in the
cytoplasm of moist green cells. In higher plants exchange of gases occurs through stomata of
leaves.

iii. HETROGAMY:
In land plants different male and female gametes are formed called heterogametes and
the process is termed as hetrogamy. In this process two distinguish male and female gametes
are formed. The male gametes are ciliated or flagellated, while the female gametes are non-
motile. The female gametes contain stored food material which is used during the process of
reproduction.
iv. PROTECTION OF REPRODUCTIVE CELLS:
The land plants have special system of protection of their reproductive organs, e.g. in funaria
the antheridia (male organs) and archegonia (female organs) are provided with long
structures called ‘paraphyses’. They protect the reproductive organs which are produced in
chambers. They remain protected properly.

v. FORMATION OF EMBRYO:
In land plants after fertilization zygote is formed in the archegonium.
The zygote develops into embryo. The embryo is covered by certain layers which are
produced from archegonium. These layers protect the embryo from drying conditions.

CLASSIFICATION OF BRYOPHYTES

Division of bryophytes is divided into three classes.

i. Music ( Mosses )
ii. Hepatica ( Liver worts)
iii. Anthocerotae ( Horn worts)

i. CLASS MUSCI:
Introduction:
It is the most common and familiar class of bryophytes. They are commonly called
‘Mosses’. They are concluded as the highly developed plants of bryophytes.

Main characters:

 OCCURRENCE:
These are the most commonly occurring plants with more than 14,980 species found in the
moist ground under trees, on rotting logs in the fields or on shaded moist places forming
spongy mats.
  FORMATION OF MATS:
A mat of moss actually consists of many plants growing in tight pack, helping to hold one
another up. The mat has a spongy quality that enables it to absorb and retain water. Each
plant of the mat grips the substratum with elongated cell or cellular filaments called rhizoids.
 STRUCTURE:
At the base of a plant number of multicellular rhizoids are present which absorb water and
minerals and anchor the body “stem”, “leaves” and “roots” (rhizoid) are not true. They are
not homologous but analogous (similar in function but different in structure) to stem, leaves
and roots of vascular plants. The leaves have distinct midribs.
 NUTRITION:
They contain chlorophyll and hence prepare their own food material within the body. Most of
the photosynthesis occurs in the upper part of the plant, which has many small stem like and
leaf like appendages.
 GAMETOPHYTE AND SPOROPHYTE:
The gametophyte consists of stem and leaves. The antheridia are produced from superficial
cell of the thallus. Sporophyte consists of foot, seta and capsule.
Example: Moss.

ii. CLASS HEPATICAE:

Introduction:
Hepatica are even less conspicuous plants than mosses. It is a group of thalloid liver worts
consisting of 84, 60 species. They are commonly called liver worts.

Important Characters:
Their main characters are follows:

 OCCURRENCE:
It grows on moist, damp places and old walls, so it is found in marshy areas of all over the
world. It is found on main rocks or woods and abundantly present in tropical forests in many
diverse form.

SHAPE OF PLANT:
They are liver shaped. The thalloid bodies of some are divided into lobes, giving an
appearance that must have reminded some of the lobed liver of an animal.

 ANATOMY:
 Internally the body is either simple or consists of many tissues. The photosynthetic cells
contain many chloroplasts without pyrenoid. Hence they can prepare their own food material
inside their body.
 STRUCTURE:
The plant body is called thallus i.e. can’t properly differentiated into roots, stem and leaf.
Branching:
The plant body is dorsoventrally dichotomously (divided into two) branched thalloid.
Midrib:
Thallus is ribbon shaped green in colour containing a thick vein in its middle called as ‘midrib’.

 DORSAL SURFACE:
Following structures are present on dorsal surface:
i. Gemma Cup:
The thallus on its dorsal surface bears number of cup like structures called Gemma cup.
These are located on midrib. They produce gemmae which help in vegetative reproduction.
ii. Rhombic Area:
The whole dorsal surface is covered by numerous rhombic areas. Each rhombic area has the
small opening called air pores (ostiole). These pores lead inside the air cavity and supposed to
be primitive stomata.

 VENTRAL SURFACE:
Following structure is seen in ventral surface:

i: Rhizoids:
On the ventral surface just below the Gemma cup, hairs like structures are present called
‘rhizoids’ which are meant for the absorption of food material. These rhizoids are unicellular.
They also help in the fixation of thallus in the soil.

 REPRODUCTION:
The reproductive bodies are formed from the superficial cells in the dorsal side of the thallus,
except when terminal is present.
i. Gametophyte:
The body of gametophyte is either thallus like or the body is differentiated into stem and
leaves. In the capsule spore mother cells are produced which give rise to spores.
ii. Sporophyte:
The sporangium is simple or differentiated into foot, seta and capsule.
Example: Marchantia.
iii. CLASS ANTHOCEROTAE:
Introduction:
This is the most advanced group. These constitute the most highly evolved group of these
amphibious plants with only more than 3,000 species.
Important Characters:
The advanced characters developed towards terrestrial trends are as under:

 SHAPE:
As the name suggests these horn worts with the thalloid body of gametophyte grow in the
form of elongated capsules like horns in their sporophytic stage hence they are commonly
called as ‘horn worts’.

 STRUCTURES AND EXISTENCE:

Horn worts resemble liver worts but are distinguished by their sporophytes which are
elongated capsules that grow like horns from the mat like gametophyte. The sporophyte
shows many advanced characters suited for land environment.
 NUTRITION:
 The sporophyte contains chloroplasts and stomata, perform the function of photosynthesis
i.e. they are able to prepare their own food inside their body.

Meristematic tissues (growing at tips) has developed by which new cells go on adding and the
plant is able to survive independently often even after the death of gametophyte.
Example: Antheceros fusi formis.

LIFE CYCLE OF BRYOPHYTES: (moss)

 All bryophytes show heteromorphic alternation of generation with gametophytes as
dominant generation.
 The gametophyte is haploid consisting of rhizoids, pseudo stem and leaves.
 Gametophytes maybe unisexual or bisexual depending upon whether stem is branched or
un branched.
 The sex organs called antheridia and archegonia develop at the tips of stem which are
always diocuos having either male or female sex organs.
 When archegonia mature, they have single ovum in the venter and few neck canal cells in
the neck.
 Swimming sperms are attracted by scent of sugar cane secreted by mature archegonium
but a single antherozoid fuses with the ovum to form diploid (2n) oospore (zygote).
 This is retained within archegonium and form an embryo (2n).
 This embryo undergo repeated mitotic-divisions to form sporogonium (a sporophyte)
which is diploid. It consists of foot, seta and capsule.
 Within capsule spore mother cells are present. Each spore mother cells divides by meiosis
to form four haploid spores.
 Each spore germinates into a filamentous body called protonema.
 Later on gametophyte (haploid) develops from protonema to complete life cycle.

TRACHEOPHYTA
INTRODUCTION:
The tracheophytes, by contrast have evolved a host of adaptations to the terrestrial
environment that have enabled them to invade all but all the most inhospitable land habitats.
In the process they have diverged sufficiently from one another.

ADAPTION FOR LAND HABITAT:

The plants of this division has four fundamental adaptions for terrestrial habitat. They are as
follows:

i. PROTECTION OF REPRODUCTIVE CELLS:

Protective covering are developed around the reproductive organs in the form of jacket cells
(sterile cells).

ii. DEVELOPMENT OF EMBRYO IN FEMALE ORGAN:

Fertilized egg or zygote in the developing young one is called embryo. It is retained within the
internal tissue of female reproductive organ, called archegonium.

iii. DEVELOPMENT OF WATER PROOF COVERING:

 These plants have water proof or waxy covering around then aerial parts called ‘cuticle’. It
prevents the loss of water by evaporation.

iv. DEVELOPMENT OF VASCULAR TISSUES:

Xylem the special tissue for conducting water and food material are developed. They conduct
and carry these substances from one part to another. They also support and fix body firmly.

CLASSIFICATION OF TRACHEOPHYTES

The division tracheophyta is divided into five sub-divisions.

i. Sub-division Psilopsida (Psilopsids)
ii. Sub-division Lycopsida (Club mosses)
iii. Sub-division Sphenopsida (Horse tails)
iv. Sub-division Pteropsida (Fern)
v. Sub-division Spermopsida (Seed plant)

i. PSILOPSIDA:
Introduction:
It is an undisputed group of oldest extinct plants while appeared 400 million year before in
the Silurian period and become extinct in Devonian period. Rhynia offers the best example of
these oldest extinct plants.

Main Characters:
Some of the important characters are described below;

 BODY STRUCTURE:
The main body is sporophyte. The body consists of underground rhizome like structure and
an aerial portion. They had simple dichotomous branches; above the point of bifurcation.
Branches were equal in size. They had sporangia at the tip of these branches.

 ROOT:
True roots are absent. Rhizoids are produced from the rhizome which helps in the absorption
of water. These rhizoids are microscopic unicellular similar to root hairs.

 STEM:
Stem is present which lack cambium tissues, so there is no secondary growth. The vascular
tissues of stem are very primitive in structure and arrangements. Aerial stem in green, takes
part in photosynthesis.

 LEAVES:
Leaves are small, simple, scale and spirally arranged.

 REPRODUCTION:
Asexual reproduction takes place by sporangia, produce at the tips of aerial branches. In
sporangia haploid spores are produced by meiosis. Spores are of same type (homosporus).

ii. LYCOPSIDA:
INTRODUCTION:
 It is a group of vascular plants which appeared in the middle of the Devonian period, almost
10 million years after the first psilopsida. Some of them are very large trees that formed the
earth’s first forest.
EVOLUTIONARY IMPORTANCE:
They become extinct and the group survives with only five living genera, including Lycopsida
and Selaginella. It is a group of evolutionary significance as they developed anatomical
features and methods of reproduction, which suited more for adaptions on land.

Main Characters:

Their main characters are as follows:

 ORIGINATION:
They possess proper plant body and they are suggested to be originated from ancestral algal
forms, which penetrated and branched underground giving rise to true roots.

 LEAVES:
They have developed and true leaves, which thought to have arises as simple scale like
outgrowth (emergence) from the outer tissues of the stem. The leaves are small and simple.
Each leaf has as a single vascular bundle.

REPRODUCTIVE STRUCTURES:

 SPOROPHYLLS:
Some of the leaves in these plants become specialized to bear reproductive structures
(sporangia). Such leaves are called sporophylls.

 STROBILLI:
In many lycopsids the sporophyll are conjugated a short length of stem and form cone like
structures called strobillus. The cone is rather club shaped, hence the name ‘club mosses’ for
lycopsids. Though lycopsids are not related to the true bryophytes.

 SPORE FORMATION:
*HOMOSPORUS CONDITION:
Spores are produced by lycopodium are all alike, and each can give rise to gametophyte that
will bear both archegonia and antheridia, hence they said to be homosporus.

*HERTROSPORUS CONDITION:
Some lycopsids (e.g. Selaginella) produces two types of sporangia, which produced different
kind of spores.
Megaspores:
One type of sporangium produce very large spores called megaspores, which developed in
female gametophytes bear archegonia.
Microspores:
The other type produces many small spores called microspores, which developed into male
gametophytes bearing antheridia.
The sexes are separate in gametophyte generations, hence they are said to be
‘heterospores’.

RHYNIA:
  Rhynia, an extinct genus was named after the village. Rhynia of Scotland, where the fossils of
Rhynia were discovered.
 It belongs to Devonian period, which started about 400 million years ago.
 The fossils of this plant are so well preserved that the stomata are still intact.
STRUCTURE:
 The plant body (sporophyte) of Rhynia was simple.
 It consisted of slender, dichotomously branched creeping rhizome, bearing erect,
dichotomously branched aerial stem.
 Instead of roots, Rhynia was given out from rhizome.
 The aerial branches were leafless having terminal fusion naked sporangia.

MICROSCOPIC STUCTURE:
 The internal structure of branched show a solid central core of vascular surrounded by
cortex.
 The outermost layer is epidermis, having stomata.
 The vascular tissue is differentiated into centrally placed xylem and surrounded phloem.

EVOLUTION OF LEAF:
The leaf is the most important organs of green plants because of its photosynthetic activity.
Leaves are of two types:
i. Microphyllous or single veined leaves (contain only one vein).
ii. Megaphyllous or poly veined leaves (contain two or more vein).

Evolution Of Single Veined Leaf:

i. Its evolution can be explained by assuming that a thorn like outgrowth emerged on the
surface of the naked system.

ii. With an increase in size of the leaf of vascular tissues were also formed for the supply of
water and support of leaf.
iii. Another possibility is of a part of the leafless branching system of the primitive vascular
plants.

i. Evolution Of Poly Veined Leaf:

ii. These are evolutionary modification of the forked branching system in the primitive plants.
iii. The first step in the evolution of this leaf was the restriction of forked branching to a single
plant.
iv. The next step in the evolution was filling the space between the branching and vascular
tissue.
v. The branching system become flat.
vi. The leaf so formed looked like the webfoot of a duck.

EVOLUTION OF SEED:
It is evident that seeds are evolved from primitive spores.
Stages Of Evolution:

Evolution of seeds involve following stages:

i. ORIGIN OF PRIMITIVE SPORES:
Less developed plant like Rhizopus etc produce only one kind of spore. All spores of species
are nearly identical in size, structure and function.
 ii. DEVELOPMENT OF HETEROSPORES:
There are many vascular plants that form two kinds of spores. These plants are said to
heterospores. These spores on germination give rise to two different types of plants.

a. Male plant:
It produces sperm forming gametophyte plant.
b. Female plant:
It grows into egg forming gametophyte.

iii. PROTECTION OF HETEROSPORES:

 Two different kinds of spores are formed in two different kinds of sporangia.
 They have become protected as a result of the evolution of various enveloping
structures.
 About 280-350 million years ago certain ferns like plant bear seed like structures.
Each of their sporangia containing one or more female spores, was surrounded the
outgrowth which appears to have been little branch like structure. These form
‘integument’.

iv. PERSISTANCE OF FEMALE SPORES:
Instead of being shed from the sporangium, the female spores are retained and
protected inside the integuments in seed plants. The female spore develops into a
tiny female gametophyte protected by the integuments.

v. DEVELOPMENT OF SEED:
Seed is formed as a result of fertilization of male spores with this protected female spore.
Immature seed is called ovule. On examining the ovule, it is found that it is protected by
integuments and it contains great quantities of food. Thus the ovule not only protects the
female gametophyte from the environment, it also provides food for the new offspring that is
produced when the seed mature and germinate. The development of seed has given the
vascular plants better adaptations to their environment.

iii. SPHENOPSIDA (Horse tails):

Introduction:
It I an extinct group of lower vascular plants, which survives by the single genus ‘Equisetum’.
They first appeared in the fossil record late in the Devonian period. They became a major
component of the land flora during the Carboniferous period and then declined. The
members of this division are called horse tails.

Main Characters:
The main characters are as follows:
 OCCURRENCE AND SIZE:
Their existing forms are widely distributed over the earth being especially abundant in the
marshy places. It is a short slender herb hardly exceeding one meter. But though climbing on
bushes some species may attain a height of 3-4 meters.

 BODY STRUCTURE:
They possess proper plant body consisting of true roots, stem and leaves.
o Roots:
True roots are present for the absorption of water and minerals. Roots are adventitious.
o Stem:
 Stem are hollow and joined possessing whorls of leaves at each joint. The stem has distinct
nodes and internodes.
o Leaves:
The leaves are scale like. The leaves are produced in whorls and form a sheath at the side
around each node.

 SECONDARY GROWTH:
Extinct form of sphenopsids possesses cambium layer (not present in existing forms), so they
were able to exhibit secondary growth.

 REPRODUCTIVE STRUCTURES:
Main plant is sporophyte. The sporangia are born on sporangiophores and are arranged in
the form of terminal cones called strobili. In Equisetum all spores are alike (i.e. the plants are
homosporus) and give rise to small gametophytes that bear both archegonia and antheridia
(i.e. the sexes are not separate)

iv. PTEROPSIDA (Ferns):

Introduction:
It is a very widely distributed group of highly developed tracheophytes comprising of 12,000
species ranging from small aquatic plants to giant trees of tropical forests which may grow to
30-40 feet.

Origin, Evolution, Extinction and Survival:

Ferns are suggested to be evolved from psilopsids, the oldest extinct plant according to
geological records. They appeared 400 million years back in the late Paleozoic era in
Devonian period. They became dominant and increase in number during carboniferous
period. There down fall was much less than lycopsids and sphenopsids of their time. They
evolved and flourished and still survive with thousands of named species.

General Characters:
Their general characters are as follows:
 OCCURRENCE:
They are worldwide in distribution. They grow in different habitats. Mostly they are found in
moist and shady places. They are abundant in damp mountain forests of the tropical region,
but many of them also grow in strong sunlight and even in xerophytic conditions. Many ferns
are epiphytic. E.g. Drynaria. Some occur in water. E.g. Azolla.

 BODY STRUCTURE:
They are fairly advanced plants with a very well developed vascular system. Plant body can be
differentiated into true roots, stem and leaf.
o Roots:
True roots are present. These are adventitious (fibrous) growing from the rhizome.
o Stem:
In a few ferns (e.g. the large trees ferns of the tropics) the stem is upright, forming a trunk.
But in most modern ferns specially those of temperate regions, the stems are prostrate on or
in the soil and the large leaves are the only parts normally seen. This stem is subterranean
rhizome but in some ferns it is aerial and erect.
o Leaves:
Leaves are flattened probably evolved by the branching (dichotomously) system and tissues
in between (branches) developed. These provide a large surface area for photosynthesis,
 unlike the leaves which were found in Lycopsids and Sphenopsids, which were developed
differently and they are called emergence leaves.
Leaves are mostly compound, consisting of number of leaflets occasionally simple
leaves are present.

Part of leaf:
Each leaf consists of two parts.
i. Petiole
ii. Blade
The petiole is covered with hairs called ramenta. The blade is either simple or pinnately
compound i.e. divided into many small leaflets called pinnae and pinnules.

NATURE AND SPORES PRODUCTION:

The large leafy fern plant is the diploid sporophyte phase. Spores are produced in sporangia
located in clusters on the underside of some leaves (sporophylls). In some species the
sporophylls are relatively little modified and look like the non-reproductive leaves. In other
species the sporophylls look quite different from vegetative leaves. Sometimes they are so
highly modified.

TYPE OF SPORES:
Most modern ferns are homosporous i.e. all these spore are alike. After germination the
spore develops into gametophytes that bear both archegonia and antheridia. These
gametophytes are tiny (less than one centimeter) thin and often more or less heart shaped.

 ALTERNATION OF GENERATION:
Fern plant passes through two stages of generation to complete its life history. The plant
itself is a sporophyte (2n). It reproduces asexually by spores and gives rise to gametophyte
which reproduces sexually by fusion of gametes and give rise to sporophyte. And as such two
generations regularly alternate each other.

LIFE CYCLE OF FERN:

The life cycle of fern shows heteromorphic alternation of generation in which sporophyte
phase is dominant generation. All ferns are homosporous producing single types of spores.

- The sporophyte which is diploid consists of adventitious roots, underground stem a rhizome
and pinnately compound leaves.

- Reproduction takes place by means of haploid-spores formed from the spore mother cells
after meiosis inside sporangium. A number of sporangia develop inside single sorus.

- Each sporangium consists of a stalk called sporangiophore and a biconvex capsule consisting
of annulus and stomium. Within sporangium spore mother cells are present. Each spore
mother cells divides by meiosis to form four haploid spores. The spores are liberated through
stomium.
- Each spore on germination gives rise to miniature bisexual gametophyte called prothallus

-Each archegonium consists of venter with an ovum and a neck. Each antheridium produces a
number of antherozoids (sperms).
 - A number of sperms, by making chemotactic movement in water reach to the archegonium.

- Only one sperm fuses with ovum to form oospore which is diploid. Young sporophyte
develops from the oospore. In the meantime, prothallus degenerate. In this way life cycle is
completed.

V. SPERMOPSIDA:
Introduction:
It is the most successful group of higher vascular plants. These are the plants which produces
fruits and seeds.

Origin, Evolution And Dominance:

They first appeared in the late Devonian and in the Carboniferous they soon replaced the
Lycopsids and Sphenopsids as the dominant land plants, a position they still hold today. The
seed plants have been by far most successful in fully exploiting the terrestrial environment.

EVOLUTION OF ESSENTIAL CHARACTERS FOR SUCCESSFUL LAND ADAPTIONS:

There were two essential characters, the development of which resulted in successful
adaption of these tracheophytes.
i. Evolution and production of seed.
ii. Escape from dependence of water for fertilization and evolution of pollen tube.

i. Seed Production:
 Seed production is one of the most important characters for the adaptions of amphibious
plant on land specially spermopsida. The development of protective covering around the
immature seed (an ovule) with accumulation of large quality of food provides embryo not
only protection but the nourishment for the developing stages. The young embryo with all
nutrients get encased in resistant coats (seed coats) remain dormant under any dry
conditions for long period under unfavourable conditions.

ii. Escape From Dependence On Water For Fertilization:

 In seed plants the gametophyte are further reduced and the sperms are uniflagellated.
 In Spermopsida, when sperms (or pollen) through any external agency wind, insects, animal
etc; reaches the female organ, it produces or form a pollen tube. It serves as tunnel through
which non-flagellated sperms travel to reach the egg.
 The eggs are enclosed into the ovaries or ovules encased in surrounded layer of integuments
are so well protected that the sperms would not have the slightest choice of ever reaching
them for fertilization. It is only through this device (formation of tube) that fertilization is
made possible.

CLASSIFICATION:
The seed plants have traditionally been divided into two groups:
i. The Gymnosperm
ii. The Angiosperm

GYMNOSPERMS
Preface:
The word gymnosperm is a combination of two words Gymnos means naked and Sperma
means seed. Hence these plant bear naked ovules without ovary so, they are called naked
seeded.
Origin and Evolution:
It is a group of plants found all over the world. According to fossilian records, they appeared
in the late Devonian; some 350 million years ago. They were the first seed producing plants
with vascular tissues. They closely resembled fern and were called seed ferns.

General Characters:
There general characters are as follows:
 OCCURRENCE:
These are ever green trees and found all over the world, an account for about 1/3 of the
world’s forest. They maintain their dominance only in the cold climates and on the mountains
of the world including sub-continents.
 SEED, FRUITS AND FLOWERS:
Their seeds are naked not enclosed in an ovary or fruit.
Flower are in the form of cone so, they are called coniferous plants.
They don’t bear fruit as there is no ovary.
Cones generally called sporophylls bear sporangia in which spores are developed.
 AGENT FOR SEXUAL REPRODUCTION:
These plants are heterospores, producing two types of spores i.e. microspores and
megaspores. Water is not required for the sexual reproduction as pollen grains are carried by
wind.
Pollen tube formation is developed by which they could escape from dependence on water
for fertilization, a character playing key role for perfect terrestrial adaptations from
amphibious forms of life.

PINUS:
INTRODUCTION:
Pinus is a member of Gymnosperm. It is a large sized tree growing obliquely straight with
erect stem about 50-60 meters long and 2-3 meters in diameter. It is ever green plant.
OCCURRENCE AND IMPORTANCE:
Pinus mostly grow in the mountains regions of Pakistan, which are of great economic
importance. They not only provide timber but they are best soil binders of hilly region
MORPHOLOGY OF PINUS:
 Long tree of pinus is differentiated into three parts.
i. Roots
ii. Stem
iii. Leaf

 Roots:
True tap roots are present which does not persist but gives are large number of profusely
branched roots which spread for a considerable distance. These persist whereas original root
disappears.
 Stem:
Stem is cylindrical shaped bearing dimorphic branches.
i. Branches of unlimited growth or long shoots.
ii. Branches of limited growth or drawf shoots, called Spurs.
 Leaves:
These leaves are also dimorphic.
i. Scaly leaves
ii. Foliage leaves

i. Scaly Leaves:
They grow small scale like leaves produced on long shoots at early stage for protection. After
that they fall on the ground.
ii. Foliage Leaves:
These leaves are produced on dwarf shoots. They are long needle like, so called needles.
They are green in colour and manufacture food material.

LIFE CYCLE:
The adult plants of Pinus represent the sporophytic phase of life cycle. The sporophytic plant
of Pinus reproduces asexually by means of spores and after passing through gametophytic
phase of life cycle again produces sporophytic plant. Thus show a distinct alternation of
generation.

i. SPOROPHYTIC PHASE:
The sporophytic plants of Pinus are mostly monoecious i.e. male and female cone are found
on the same plant. Special reproductive organs called cones or strobili (singular:strobilus)
developed on it.

 Male Cone:
i. The male cones occur in clusters near the end of long branches at the place of dwarf shoot
(dwarf shoots are replaced by male cone).
ii. Each male cone is a simple ovoid structure 3-4cm in length.
iii. It has got single centrally located cone axis around which are arranged spirally, many scaly
microsporophyll (60-135).
iv. Each microsporophyll has an expanded triangular central part and a stalk like base. It bears
two microsporangia.
v. Each microsporangium, which is borne on the lower side, bears numerous pollen grains
mother cells.
vi. When the microsporangium mature, a horizontal slit is formed on its lower side through
which numerous pollen grains are liberated and dispersed by wind.
vii. Each pollen grain is winged structure and yellow in colour.
 Female Cone:
i. The female cones are developed laterally in the axis of scale leaves.
ii. The female cones are much bigger, woody, dry and hard structure.
iii. The young female cone is reddish green structure.
iv. Each female cone consists of a central axis to which are attached the megasporophyll.
v. Each megasporophylls on its surface has two ovules. Each ovule is orthosporus and consists
of a central mass of tissues, surrounded by a single integument made up of three layers. The
integument bears a wide gap, the micropyle.
vi. Within the megasporangium, megaspore mother cells are present, which undergo reduction
division to produce megaspores.
vii. Only one megaspore is functional,however the other three degenerate.

ii. GAMETOPHYTIC PHASE:

The spores are the units of gametophytic phase of life cycle. In case of Pinus the spores are of
two types, microspores and megaspores.

 Male Gametophyte:
i. The microspore is a unit of male gametophyte.
ii. Each microspore or pollen grain is a unicellular body covered with an outer layer exine, thick
and heavily cuticularized while the inner layer, intine is very thin.
iii. The exine forms the balloon shaped wings on the either side which help in pollination.
iv. The microspore is at this four cells stage consisting of one generative cell and two prothalial
cells and a tube cell.

 Female Gametophyte:
i. The megaspore is the first cell of female gametophyte.
ii. The functional megaspore increases in size and forms a complete cellular female
gametophyte, also known as endosperm.
iii. The archegonia are formed towards the micropylar side.
iv. The cells of the endosperm or archegonium initially divide and form the central cell.
v. The central cell forms the venter canal cell and a large egg cell.

POLLINATION:
In case of pinus, pollination is effected by wind (anemophyllous).

FERTILIZATION:
i. The pollen grain reaches the apex of the archegonium.
ii. The pollen tube carrying the two male gametes and the tube nuclei comes in contact with the
archegonium.
iii. The tip ruptures discharging its contents into the egg.
iv. One of the male gamete fuses with the egg nucleus and unites forming oospore or zygote.
v. The second male gamete along with the tube and tube nuclei disintegrate.

SEEDS:
Fertilized ovules get transformed into seeds. Seeds are small elongated and winged.

GERMINATION OF SEED:
The seeds undergoes into a condition of dormancy. When the conditions are favourable the
seeds absorb moistures and the embryo resumes growth.
 LIFE CYCLE OF AN ANGIOSPERM
Life cycle of an angiospermic plant can be differentiated into two phase.
 Sporophyte phase
 Gametophyte phase
SPOROPHYTE PHASE:
i. It is predominant phase of angiosperm.
ii. It has diploid or 2n number of chromosomes.
iii. It bears flowers which are reproductive parts.
iv. The flowers are sporangia.
v. Male sporangium is anther and female sporangium is called carpel.
vi. Anthers and carpel produce male and female gametophyte.

GAMETOPHYTE PHASE:
In this phase plants can be differentiated into male and female gametophytes.

 Male Gametophyte:
Pollen grains are considered as male gametophyte. They are produced into anthers. They
contain haploid (n) numbers of chromosomes.

 Female Gametophyte:
i. Embryo sacs are considered as female gametophytes.
ii.They are developed in the ovary of a carpel.
iii.They also contain haploid no. of chromosomes.
iv.It usually has 8 nuclei.
v.The embryo sac is nourished and retained by the Sporophyte within a structure called the
ovule.

POLLINATION:
The pollen grains are transferred from the anther to the stigma, usually by wind or insects,
the process being called pollination.
FERTILIZATION:
i.On reaching the carpel, pollen grains begins to germinate sending a pollen tube to the style.
ii.The gamete nuclei are eventually discharged into the embryo sac.
iii.One fuses with the egg cell to produce the zygote (zn) and the other fuses with the polar nuclei
to form the endosperm nucleus and the triploid cell divides to form the endosperm

FORMATION OF SEED AND FRUIT:

i. The ovule becomes the seed and the ovary enclosing it, the fruit.
ii. The fruit has protective function for the developing seeds and is often involved in the dispersal.

GERMINATION OF SEED:
The nature and nipped seed undergo a period of rest and germinate under optimum
condition of water and temperature. They give rise to a baby plant or seedling which grows
into an adult plant.

STRUCTURE OF OVULE:
Microscopic study of an ovule reveals following structural features of an ovule.
 FUNICLE:
It is slender stalk of ovule through which it attaches to plancenta.
 HILUM:
 It is the point of attachment of the body to its funicle.
 RAPHE :
In the inverted ovule, the funicle continues beyond the hilum along side of the body of the
ovule forming a sort of ridge, which is called raphe.
 CHALAZA:
The distal end of the raphe which is the junction of integument and the nucellus is called
chalaza.
 NUCELLUS:
It is the main body of ovule.
 INTEGUMENTS:
Nucellus is surrounded by the two coats called the integuments.
 MICROPYLE:
It is the small opening at the apex of the integuments.
 EMBRYO SAC:
It is a large, oval cell lying embedded in the nucellus towards the micropyle end. It is the most
important part of the ovule as it bears the embryo. It is further developed and in the mature
embryo sac following cell can be seen:
 EGG APPARTUS:
It is the group of three cells lying towards the micropyle. One cell of the group is female
gamete, the ovum and the other two cells are synergids. The ovum or egg cell on fertilization
gives the embryo synergids get disorganized soon after fertilization.
 ANTIPODAL CELLS:
This is the groups of three cells lying at the opposite end of egg apparatus. They have definite
function.

 DEFINITE NUCLEUS:
In the middle of the embryo sac there are distinct nucleus known as definitive nucleus which
is the fused product of two polar nuclei.

STRUCTURE OF POLLEN GRAIN:

Pollen grains are the male reproductive bodies of a flower and are contained in the pollen
sac. They are very small in size, usually varying from 10µm-200µm. microscopic study of a
pollen grain shows following features:

a) EXINE: It is the outer coat of pollen grain. It is though, cutinized layer which is often
provided with spinous outgrowths or marking of different patterns, sometimes smooth. It has
one or more weak slits or pores called Germ pores.
b) INTINE:
It is the inner coat of pollen grain. It is a thin, delicate, cellulose layer lying internal to the
exine. During fertilization in times grows to form pollen tube.

 INTERNAL STRUCTURE:
Each pollen grain contains a bit a cytoplasm on a nucleus. During germination of pollen grain
the nucleus further grows and divides to form a tube nucleus and a smaller one the
generative nucleus. The generative nucleus soon divides into two male gametes.
FERTILIZATION:
It can be defined as a process of fusion of male and female gamete which results in the
formation of diploid zygote.

Male Gamete-Pollen Grain:

 Each pollen grain consists of a single microscopic cell and possesses two coats:
i. Exine
ii. Intine
 Exine is outer tough layer and intine is inner soft layer.
 Two nuclei may be seen in pollen grain of which the larger one is vegetative or tube nucleus
and smaller one is generative nucleus.
 Generative cell further divides to form two male units.

Female Gamete-Ovum:
 Female gamete ovum is developed in embryo sac which in turn develops into the ovule.
 In the mature embryo sac following types of cells are found.
 EGG APPARATUS: Present in lower side and contains one ovum and two synergids which
disorganized later.
 ANTIPODAL CELLS: Present at the opposite end of the embryo sac.
 DEFINITIVE NUCLEUS: Lies centrally.

THE PROCESS:
The pollen grain is attracted to the stigma by sugary substance released from it. The process
of fusion occurs in following steps:

Germination Of Pollen Grain:

 After pollination the growth of the pollen tube is stimulated by the cell sap of the stigma.
 On exine of pollen grain pores are present called ‘germ pores’. It is the place where the pollen
tube comes out.
 Pollen tube is the extension of intine through germ pores.

Growth Of Pollen Tube:

 The pollen tube grows towards ovule.
 It penetrates the style.
 Finally it reaches the micropyle.

Fusion Of Gametes:
 At micropyle, pollen tube discharges the two sperm nuclei into the embryo sac.
 One sperm nucleus fuses with definitive or fusion nucleus to form the triploid primary
endosperm nucleus from which the endosperm develops.
 The other sperm nucleus fertilizes the egg nucleus to form the diploid oospore or zygote. This
will ultimately develop into an embryo.

Double Fertilization:
Since one sperm nucleus fertilizes the egg nucleus and the other the definitive nucleus, this
process is termed as double fertilization.
 THE FLOWER
DEFINITION:
“The flower is defined as a highly modified shoot meant essentially for reproduction of the
plant.”

FORMATION OF FLOWER:
It is developed in the axil of a leaf or at the apex of stem and branch. It bears bracts at its
base. The flowers are also produced in groups, which is called inflorescence.

ASSOCIATED PARTS:

 STALK OF PEDICLE:
 The flower is produced at the apex or tip of a stalk called pedicel. The flower having pedicel is
called pedicellate. If pedicel is absent, it is known as sessile. Sometimes, the pedicel may be
very short, and then the flower is called sub-sessile.
 THALAMUS:
The tip or end of the pedicel to which floral parts are attached is usually enlarged or swollen,
it is known as receptacle or thalamus.
 BRACTS:
If the bracts are present in the axil of flower, it is called bracteates and if they are absent, it is
termed as ebracteate.

FLORAL ORGANS:
A flower consists of four types of floral organs. These parts are arranged in whorls in a
definitive order. These organs are as follows.
i.Calyx
ii.Corolla
iii.Androecium
iv.Gynocium

CALYX:
Composition:
This is the and outer most whorls, composed of small, leafy structure called sepals. They are
usually green, but sometimes they are highly coloured, called petaloid.

Function:
Calyx covers the inner part of the flower and protects them from sunlight and rain. The sepals
enclose and protect all the other floral parts during bud stage.

Further Description:
When the sepals are free it is called poly sepalous, when they are united together, it is
termed as gamo-sepalous sometimes are modified into hairs and called pappus e.g.
Compositae family

CORROLLA:
Composition:
This is second whorl and composed of expanded and brightly coloured structure, called
petals.

Function:
They may also have glands which produce juicy substances. Due to this juice and colour of
petal, Honey Bee, butterflies and other insects are attached and thus help in the pollination
of flowers.

GYNOCIEUM:
Composition:
It is the fourth whorl and occupies a central position of flower. It is female whorl of the flower
and composed of carpels.
 Parts Of Pistil:
Each pistil consists of three parts

 STIGMA:
It is the uppermost swollen part which receives pollen grains.

 STYLE:
From the stigma, a thin stalk like portion extends downwards called as style.

 OVARY:
Ovary is the basal swollen part of the carpel. Ovary is converted into fruits and ovules into
seeds.

Chambers Of Ovary:
The ovary has one or more chambers. Each chamber contains one to many ovules. The
ovary having one chamber is called unilocular and when many chambers are present it is
known as multilocular. The ovules are attached to the wall of ovary by small structures called
It petals are free, it is called poly-petalous and if petal are fused together, it is known as
gamo-petalous. In same flowers sepals and petals do not differ in shape and colour and their
members ane alike to form a single part of a flower.

ANDROCIEUM:
Composition:
It is the third whorl of the flower and it is called male reproductive part of flower. It is
composed of male reprodcyive organs called stamens.

Parts Of Stamen:
Stamen consists of three parts filament, connective and anther.
i. FILAMENT:
It is a slender, soft and rod like.
ii. CONNECTIVE:
Connective is the junction between anther and filament.

iii. ANTHER:
Anther is the expanded head born at the tip. Each anther has two lobes and each lobe
produces two chambers called pollen sacs. Within each pollen sac the pollen grains are
present, which are the male reproductive bodies.

Function:
At the base of androcieum small green necteries containing nectar (a honey like substance)
are present. These attract insects and thus help in the pollination of flowers
.
Arrangement Of Carpels:
When many carpels are present in a pistil and they are free, it is termed as apocarpous and
when the carpels are united together, it is known as syncarpous.

Placentation:
Ovules are attached to the inner wall of ovary by special tissues called placentae. The ovule is
attached to the placentae by short stalk, the funicles. The arrangement of placentae within
 the ovary is called Placentation. There are several types of placentation: basal, marginal,
central, axile, parietal.

VASCULAR PLANTS AS SUCCESSFUL GROUP OF LAND PLANTS

Vascular plants are highly successful on land due to some of their specific adaptation. These
adaptations are mentioned here.

REPRODUCTIVE ADAPTATIONS:
The major advantage of land plants over other plants is related to their reproduction. Here
they are better adapted in three important ways:

 GAMETOPHYTE GENERATION IS PROTECTED AND REDUCED:

The gametophyte is greatly reduced. It is always protected inside Sporophyte tissue on which
it is totally dependent. In mosses and liver worts, where the gametophyte is conspicuous and
in ferns where it is a free living prothallus, the gametophyte is susceptible to drying out.

 DEVELOPMENT OF POLLEN TUBE:

Fertilization is not dependant on water as it is in other plants groups, where sperms swim to
the ovum. The male gamete of seed plants are non-motile and carried within pollen grains,
that are suited for dispersal by wind or insects. Final transfer of the male gametes after
pollination is by means of pollen tubes the ova being enclosed within ovules.

GENERAL ADAPTATIONS:
Others ways in which spermatophytes are adapted to life on land are summarized below:
 Supporting Tissues:
Xylem and sclerenchyma are lignified tissues providing support to all vascular plants. Many of
these show secondary growth with deposition of large amount of wood (secondary xylem).
Such plants become trees and shrubs.
 Water and Mineral Absorption:
True roots, also associated with vascular plants to absorb soil H2O efficiently.
 Outer Protective Coverings:
The plant is protected from desiccation by an epidermis with a water proof cuticle, or by cork
after secondary thickening has taken place in dicot stem.
 Development of Stomata:
The epidermis of aerial parts, particularly leaves, is perforated by stomata allowing gaseous
exchange between plants and atmosphere. Plants show many other adaption to hot and dry
environment.
FAMILIES
1. FAMILY ROSACEAE
INTRODUCTION:
It is one of the important and most familiar family owing to its conspicuous, prominent and
nectary flowers. Rosa indica is the most familiar flower, hence the family is known as Rosacea
family.

DISTRIBUTION:
It has about 2000 species belonging to 100 genera, found growing in all over the world. 213
species of 29 genera have been reported from Pakistan.
HABIT AND HABITATE:
 This family includes a large group of trees, shrubs and herbs and climbers of very
diverse form.
 Most of species are found in temperate regions, some of them are also found in
tropical and sub-tropical habitats.

VEGETATIVE CHARACTERS:
 ROOTS: Tap roots, branched.
 STEM: Herbaceous or hard and woody, shrubs and climbers are also found.
 LEAF: Alternate, simple or compound, pinnate, stipulate.

FLORAL CHARACTER
i. INFLORESCENCE:
Variable, solitary flowered to recemose and cymose cluster.

ii. FLOWER:
Pedicellate, bisexual, actinomorphic often perigynous, usually showy and scented,
pentamerous and tetramerous.

iii. CALYX:
Sometimes epicalyx is also present, sepals lobe 5 rarely 4, gamosepalous sepaloid.
AESTIVATION: Valvate.

iv. COROLLA:
Petals 5, or numerous in multiple of 5, free imbricate rosaceous, large and showy, various
usually conspicuous.

v. ANDROCIEUM:
Numerous stamens, polyandrous, usually born in many cycle of five.
ANTHER: Small and bilocular.

vi. GYNOCIEUM:
A simple pistil of 1 to numerous separate carpels or 2 to 5 carpels, united into a compound
pistil, often adinate to calyx tube.
 STIGMA: Linear, spathulate or capitates.
 STYLE: Simple, as many as carpels, free or united.
 OVARY: Superior to inferior, ovule usually 2 or more per carpel.

PLACENTATION:
Basal in apocarpous or monocarpellary flower and axile in syncarpous or multicarpellary
flower.

FRUIT:
Pome or drupe or acheme follicle.

SEED:
Non-endospermic.

FLORAL FORMULA:
♀♂, K (₅) or ₅, , C(₅) or ₅, A∞. G₁ OR (₂-₅) or ∞

DIAGNOSTIC CHARACTERS:
They can be diagnosed by following characters.
 FLOWER:
Flowers are actinomorphic, conspicuous and highly scented.
 COROLLA:
Corolla rosaceous, polypetalous,
 CARPEL:
Carpel one or many born on expanded convex or hollow thalamus, syncarpous or may be
apocarpous.
 STAMENS:
Stamens numerous, polyandrous.

ECONOMIC IMPORTANCE:

 ORNAMENTAL PURPOSE:
A large number of plants are grown for ornamental purpose. Perhaps the most widely
cultivated genus for decorative purpose is rose. Many other genera are also grown for their
beautiful flowers in the park and gardens.
 WALKING STICKS AND WOODS:
The branches of some trees provide excellent walking sticks and wood. The wood of Pyrus
pastia is used for making tobacco pipes.
 SCENTS AND MEDICINAL USE:
From many plants various scents are obtained e.g. Rose oil is used as perfume when distilled
with water the petals give rose water which is also used in various eye disease.
 MANUFACTURE OF LAXATIVE:
In Asian countries, the petals of common rose are used in making a laxative a gulkand and are
also used in the extraction of important oil, rose oil.

FAMILIAR PLANTS:
Botanical Names Common Names Local Names
Pyrus malus Apple Seb
Pyrus communis Pear Nashpati
Pyrus persica Peach Aru
Pyrus amygdalus Almond Badam
Rosa indica Rose Gulab

2. FAMILY CASALPINICEAE

INTRODUCTION:
It is one of the important legume family. Cassia fistula is an important member of this family,
hence this family is also known as Cassia family.

HABITS AND HABITATE:

The members of this family are mostly herbs, shrubs, trees or climbers.
They are worldwide distributed.

DISTRIBUTION:
It has about 2300 species belonging to 152 genera found growing in the world. 60 species
belonging to 16 genera have been reported from Pakistan.

VEGETATIVE CHARACTER:
 ROOT: tap roots, branched.
 STEM: Erect woody, herbaceous or climbimg.
 Leaf: Compound, pinnate or bipinnate, stipulate.

FLORAL CHARACTERS:
i. INFLORESCENCE:
Axillary or terminal, recemose or panicle or spikes, rarely recemose, showy.

ii. FLOWER:
Bisexual, zygomorphic rarely actinomorphic, pedicellate, perigynous, bracteate,
pentamerous.

iii. CALYX:
5 sepals free, or connate at base, often coloured. Imbricate rarely valvate.

iv. COROLLA:
Mostly five petals, free, the posterior petal inner most in the bud imbricate.

v. ANDROCIEUM:
Stamen 10 or few, polyandrous, variously connate, extra staminal disc sometimes present,
sometimes staminodes present.

vi. GYNOCIEUM:
A simple pistil of 1 carpel; unilocular, ovule 1 or many.
 STIGMA: Simple i.e. Straight and linear.
 STYLE: 1 simple, long.
 OVARY: superior.

PLACENTATION:
Marginal.

FLORAL FORMULA:
†. ♀♂, K (₅) or ₅, C₅, A₁₀, G₁

DIAGONOSTIC CHARACTERS:

i.FLOWER:
Zygomorphic, with a large upper petal (standard) inside two lateral petals.
ii.SEPAL:
5 sepals, free or slightly connate.
iii.PETALS:
5 petals, ascending imbricate.
iv.STAMENS:
10 or fewer stamens.

ECONOMIC IMPORTANCE:

i. MEDICINAL VALUE:
The leaves of Cassia fistula are used to cure ring worm and skin disease. Cassia senna is
cultivated for the leaves which yield the drug senna, which is the base for a laxative. Oil
extracted from the leaves of Cynometera cauliflora is applied externally for skin disease.
ii. COMMERCIAL VALUE:
Tamarindus indica is used in tanning. The heart wood of haemotoylon yields the dye
haemotoxylin. Common ornamental plants are Bauhinia verigata, Cassia fistula etc.
iii. SOURCE OF FOOD:
The leaves and flowers bud are used as vegetable. The acidic food of Tamarindus indica is
edible and rich in tartaric acid.

FAMILIAR PLANTS:

Botanical Names Common Names

Tamarindus indica Tamarind
Cassia fistula Amaltus
Bauhinia verigata Camel’s foot
Poinciana regia Flame of forest
Parkinosia rouburgai Vilayati kikar

3. FAMILY FABACEAE
(PAPILIONACEA OR PEA FAMILY

INTRODUCTION:
It is the most important and third largest family. Pea is an important member of this family
hence it is also known as pea family. Commonly known as Papilionaceae family because the
arrangement of flower is like a butterfly.

HABITS AND HABITAT:

Plants are herbs, shrubs or trees, climbers, aquatic plants or xerophytes. They are worldwide
distributed.

DISTRIBUTION:
It has about 9000 species belonging to 400 genera found distributed in all parts of the world.
587 species of 82 genera have been reported from Pakistan.
VEGETATIVE CHARACTERS:
i. ROOT: Tap root, branched bearing tubule containing nitrogen fixing bacteria.
ii. STEM: Herbaceous or woody, erect or climber.
iii. LEAF: Simple or common compound alternate, stipulate.

FLORAL CHARACTERS:

i. INFLORESCENCE:
Recemose or solitary axillary.

ii. FLOWER:
Pedicellate, bisexual, Zygomorphic, bracteate, hypo-perigynous, pentamerous and
papilionaceous.

iii. CALYX:
5 sepals, more or less united in a tube, sometimes two upper and three lower sepals are united
to form bilabiate structure, mostly hairy, gamosepalous.

AESTIVATION: Valvate.

iv. COROLLA:
Five petals usually free. Corolla is papilionaceous. In this form the petals are five. One of them
is usually large and clawed; this petal is called standard or vexillum. The two lateral one are
free called wings and the anterior inner most fuse to form a boat shaped structure called the
keel or carina.

v. ANDROCIEUM:
Stamens (9) + 1, i.e. 9 fuse to form a round sheath around the pistil while tenth is free. Such
arrangement can be reffered to as diadelphous.

vi. GYNOCIEUM:
A simple pistil, monocarpellary, unilocular,
hairy (to capture pollen grains).
 STIGMA: Simple i.e. linear and straight.
 STYLE: It is long because they pollinate by wind.
 OVARY: Ovary superior, ovule 1 or more.

PLACENTATION:
Marginal.
FRUIT:
Legume or pod.
SEED:
Non-endospermic or ex-aluminous.

FLORAL FORMULA:
†. ♀♂, K (₅), C₁+₂+(₂), A(₉)+₁, G₁

DIAGNOSTIC CHARACTERS:
They can be diagnosed by following characters.
 NATURE:
Trees, herbs or shrubs.
 LEAVES:
Pinnately or palmately compound or simple.
 FLOWERS:
Papilionaceous and distinctly irregular.
 STAMEN:
Stamens 10, mono or diadelphous.
 CARPEL:
Monocarpellary.
 FRUIT:
Legume. It is a type of fruit having no pulp.

ECONOMIC IMPORTANCE:

i. PROTEINACEOUS PULSES:
Main importance lies in the pulses belonging to this family and they are used as food. All
types of pulses are actually the seeds of this family which are rich in protein contents.
ii. TIMBRE AND WOOD:
Many trees of this family provide excellent timber for building furniture and fuel. Main timber
plants are Butea and Dalbergia sisso.
iii. MEDICINAL VALUE:
Many plants of this family are important for medicines, these includes glabra for cough and
cold. Clitoria ternatea is used against snake bite.
iv. SOURCE OF DYE:
Form many plants dyes are obtained, such as indigo dyes are obtained from Indigo fera (vern-
neel) and Butea monosperma yielding yellow dyes from flowers.

FAMILIAR PLANTS:
Botanical Names Common Names
Lythyrus odoratus Sweet-pea
Arachis hypogea Pea-nut
Cicer arietinum Gram
Dalbergia sisso Red wood
Sesbania aegyptica Sesbania

4.FAMILY MIMOSACEA
(ACACIA FAMILY)

INTRODUCTION:
It is one of the important legume family; it is commercially of greater importance. This family
is also known as Acacia family.

DISTRUBUTION:
It has about 3,000 species belonging to 56 genera are found growing in the world. 49 species
of 11 genera have been reported from Pakistan.

FLORAL CHARACTERS:
i. INFLORESCENCE:
Spike like ahead or umbel rarely recemose or globose umbels.
ii. FLOWER:
Actinomorphic, bisexual, hypogynous, bracteate or bracteolate, pedicellate or sessile.
iii. CALYX:
Usually of 5 sepals, sepaloid (green), generally fused toothed or lobed.
AESTIVATION: Valvate or imbricate.
iv. COROLLA:
5 petals, gamopetalous rarely polypetalous, corolla lobed, hypogynous slightly perigynous.
v. ANDROCIEUM:
5 to numerous stamens, polyandrous.
FILAMENT: filament adinate to the base of corolla.
ANTHER: versatile often crowned by deciduous gland.
vi. GYNOCIEUM:
A simple pistil, monocarpellary.
STIGMA: Terminal minute.
STYLE: Long filiform.
OVARY: superior, unilocular, ovules many.

FLORAL FORMULA:
♀♂, K (₅) or ₅, C(₅) or ₅, A∞ or ₁₀ or ₄, G ₁

PLACENTATION:
Marginal.
FRUIT:
Legume or lomentum.
SEED:
Non-endospermic.

DIAGNOSTIC CHARACTERS:
 NATURE:
Trees or shrubs.
 LEAVES:
Leaves compound, bipinnate.
 CALYX:
Tubular, valvate.
 PETALS:
Valvate or connate below.
 CARPEL:
Monocarpellary.
 FRUIT:
Mostly lomentum, which is a type of legume in which vacant space is absent and erect and
trough are present.

ECONOMIC IMPORTANCE:
i. SOURCE OF WOOD:
Many trees of this family including the species of Acacia provide commercially important
wood, which is used for construction purpose, for furniture and as a fuel. The wood of
Albizzia lebbeck is used in cabinet work and railway carriages.
ii. SOURCE OF GUM AND DYE:
Arabic gum is obtained from Acacia nilotica and katha a dye is obtained from Acacia catechu.
iii. MEDICINAL VALUE:
The leaves of Acacia nilotica are used as blood purifier.
iv. ORNAMENTAL PURPOSE:
Some common garden plants grows for their beautiful flowers Mimosa pudica etc. A few
species of Prosopis are planted in the arid zone for breaking the wind pressure.

FAMILIAR PLANTS:
Botanical Names Common Names
Acacia nilotica Gum Tree
Albizzia lebbeck Siris
Mimosa pudica Touch me not (Chui mui)
Prosopis glandulose Prosopis
Acacia catechu Katha plant

5. FAMILY POACEAE

CLASSIFICATION:
Division ------------ Angiosperm
Class ---------------- Monocotyledons
Series -------------- Glumaceae
Family ------------- Graminae or Poaceae

INTRODUCTION:

This is a family of monocotyledonous plants. It is one of the largest and economically most
important families because it includes cereal crops. It is also named as ‘grass family’.

HABIT AND HABITATE:

 The species are most numerous in the tropics but they are also abundant in
temperate region. The grasses are most universally distributed and the most
numerous in individual.
 Some of them are aquatic and others are characteristic of extremely arid and desert
places.

DISTRIBUTION:
It has about 3000 species belonging to 56 genera found growing in the world. 49 species of
11 genera have been reported from Pakistan.

VEGETATIVE CHARACTERS:
 ROOT: Adventitious, fibrous, stilt (which arise from lower part of stem. They grow
obliquely into the soil keeping the plant erect).
 STEM: Cylindrical, conspicuous nodes and hollow internodes, although solid stem are
also found.
 LEAF: Simple, alternate, longitudinal, leaf sheath mostly open, sessile, lamina narrow
and ribbon shaped.
FLORAL CHARACTERS:

i. INFLORESENCE:
Spike and spikelet.
Spikelet: In spikelet two bracts are present at the lower side, the outer or lower bract is called
first glume; and upper or inner bract is known as second glume. Each small flower also has
two bracts, the outer bract is hemma and inner bract is called palea. The lemma is also called
superior palea and other one is known as inferior palea.

ii. FLOWER:
Unisexual or bisexual, sessile, bracteate, Zygomorphic, hypogynous. Lemma and palea form
the protective covering around the flower.

iii. PERIANTH:
It is combined structure instead of calyx and corolla. Membraneous scales called the lodicules
lying on the anterior side below the stamens are regarded as rudimentary perianth.

iv. ANDROCIEUM:
It has usually 3, or 6 stamens, polyandrous (stamens are free).
FILAMENT: Long free.
ANTHER: Versatile and pendulous.

v. GYNOCIEUM:
Tricarpellary, syncarpous though only one is functional.
STIGMA: feathery.
STYLE: Short 2-3.
OVARY: Superior, unilocular, one basal ovule.
PLACENTATION:
Basal placentation.

POLLINATION:
Cross by wind (anemophilous) some of graminaceous crops such as Triticum are self-
pollinated.
FRUIT:
Achenial, grain or caryopses, rarely berry or nut e.g. Bambusa.
SEED:
Endospermic, contain straight embryo with single cotyledon called ‘scutellum’.

FLORAL FORMULA:
†, ♀ or ♂ or ♀♂, P₂ (LODICULES), A₃ OR ₃+₃ OR 0, G1 OR 0

DIAGONOSTIC FEATURES:
 NATURE:
Bracteate, glume is present. Sessile, monocot.
 FLOWER:
Flowers are usually not showy nor scented.
 ROOT:
Adventitious roots are present.
 POLLINATION:
Mostly cross pollination occurs.
  LEAVES:
Leaves are pinnate and ligulate.
 ANTHER:
Anthers versatile and pendulous.

ECONOMIC IMPORTANCE:

i. FOOD MATERIAL: This family has a great economic importance as many plants of this
family are widely used as food material, such as maize, rice etc and man depends on
these sources for most of his food.
ii. WOOD AND PAPER:
Bamboo and other plants are used as building material, afew species are also used in paper
making industry.
iii. COMMERCIAL USE:
Sugar is prepared from sugar cane and from some grasses oils and medicines.

FAMILIAR PLANTS:
Botanical Names Common Names
Triticum indicum Wheat
Avena sativa Oats
Zea mays Indian corn
Oryza sativa Rice
Saccharum officinarum Sugar cane
Hordeum vulgare Barley
Pennisetum typhoideum Bajra

6. FAMILY SOLANACEAE

CLASSIFICATION:
Division -------------- Angiosperm
Class ------------------ Dicotyledon
Sub-class ------------ Gamopetalae
Series ---------------- Bicarpellate
Order ---------------- Polemoniates
Family --------------- Solanaceae

INTRODUCTION:
It is one of the important and most familiar family of plant owing to its widely used
vegetable.
E.g. Potato family.
It is commonly known as potato family or night shade family.

DISTRIBUTION:
It has about 2000 species belonging to about 90 genera found growing in tropics and
temperate regions. 52 species of 52 genera have been reported from Pakistan.
HABIT AND HABITATE:
It is widely distributed in temperate regions and very abundant in tropical countries.
 The plants are usually herbs or climbing but in tropics many plants may be
shrubby.
 Small trees are also found.

VEGETATIVE CHARACTERS:
 ROOT: Tap root, branched.
 STEM: Aerial erect, may be herbaceous or woody, under ground in potato forming
tubers.
 LEAF: Petiolate, simple, alternate in vegetative and opposite in floral region.

FLORAL CHARACTERS:
i. INFLORESCENCE:
An axillary cyme, sometimes helicoids.

ii. FLOWER:
Pedicellate, bisexual, actinomorphic, bracteate or ebracteate, hypogynous, pentamerous,
variously coloured.

iii. CALYX:
5 sepals, gamosepalous, persistent, hairy, green, companulate (bell shaped).
iv. COROLLA:
5 petals, gamopetalous.

AESTIVATION: Rotate to tubular.

v. ANDROCIEUM:
5 stamens, polyandrous, epipetalous, alternate with corolla lobes.
FILAMENT: Usually of unequal length.

ANTHER: Anthers opening either length wise or by terminal pores, sometimes divided by false
septa, often fusing round the style.

vi. GYNOCIEUM:
Bicarpellary, syncarpous, many ovules.
STIGMA: Simple.
STYLE: Terminal, simple or lobed.
OVARY: Obliquely placed, superior bilocular or imperfectly tetra locular by false septum.

PLACENTATION:
Axile.

FRUIT:
Capsule (Datura).
Berry (Solanum nigrum).

SEED:
Minute with abundant endosperm.
POLLINATION:
Cross, entamophilous, flower protogynous.

FLORAL FORMULA:
♀♂, K (₅), C (₅), A₅, G (₂)

DIAGNOSTIC FEATURES:
 STEM:
Stem with bilocateral vascular bundles.
 LEAVES:
Alternate, becoming opposite near inflorescence, stipules absent.
 FLOWER:
Actinomorphic, pentamerous.
 STAMEN:
5 epipetalous.
 OVARY:
Bilocular, obliquely placed.

 PLACENTATION:
Axile.
 FRUIT:
Berry or capsule.

ECONOMIC IMPORTANCE:

i. SOURCE OF VEGETABLES:
Some plants of this family used as very important and nutritive vegetable.
E.g. Potato, brinjal etc.

ii. MEDICINAL VALUE:

Some plants are of medicinal value, such as the roots of Solanum xanthocarpum are used in
cough, asthma. The juice of Solanum nigrum is used in chronic enlargement of liver in
bleeding piles and dysentery. The fruits are also used in diarrhea, eye disease and
hydrophobia. The leaves of Datura metal are used in the treatment of asthma.

iii. ORNAMENTAL PURPOSE:

Many plants are cultivated in the garden for their beautiful flowers, that are scented at night
and they are used for ornamental purpose.
E.g. Petunia Alba, queen of night, etc.

iv. AS CONDIMENT:
The fruit of Capsicum and Capsicum frutescence are rich in vitamin C and A and they are used
as condiment.
v. NICOTINE AND ALKALOIDS:
Nicotiana tabacum is of great commercial value, the leaves of which are dried and made into
tobacco. It is source of nicotine. Many members of this family yield powerful alkaloids.
E.g. Atropa belladonna, Datura.
FAMILIAR PLANTS:

Botanical names Common names

Solanum tuberosum Potato
Solanum melongena Brinjal
Lycopersicum esculentum Tomato
Capsicum annum Red-pepper
Petunia alba Petunia
Solanum nigrum Black Night Shade
Datura alba Thorn apple
Nicotiana tabacum Tobacco
Atropa belladonna Deadly Night shade
Cestrum nocturnum Lady of the night
CHAPTER 10: THE KINGDOM ANIMALIA
ANIMAL:
“A true animal is eukaryotic, multicellular, heterotrophic organisms which is diploid and
developed from embryo formed by the fusion of two different haploid gametes, a large egg
and a small sperm”

CELLULAR ORGANIZATION:
The animal kingdom may be divided into branches, or subkingdom.
i.Parazoa:
Those animals, which lack a proper tissue organization, are known as parazoa. There is only
one animal phylum, which grouped into parazoa; and this is phylum PORIFERA.

ii.Eumetazoa:
All other animals’ phyla have proper tissue organization, so they are included in the
subkingdom eumetazoa.

SYMMETRY:
Members of eumetozoa are further classified into branches on the basis of symmetry.
Symmetry is the overall shape of an animal body. All the symmetrical animals can be divided,
along at least one plane, into two identical halves.

Types Of Animals On The Basis Of Symmetry:

On the basis of symmetry, animals can be divided into two types; asymmetrical and
symmetrical.
I. Asymmetrical Animals:
Animals that have no plane of symmetry are said to be asymmetrical e.g. sponges.
ii. Symmetrical Animals:
Symmetrical animals are of two types, radially symmetrical and bilaterally symmetrical.

Radially Symmetrical:
A body with radial symmetry has one main axis around body parts are arranged and the
organism can be divided into two identical halves in any plane that passes through the main
axis cnidarians and echinoderms are the examples of radially symmetrical animals.

Bilaterally Symmetrical:
Animals can be divided into identical right and left halves only by a cut through the mid line
of its body e.g. fish, lizard, frog, turtle etc.

PROTOSTOMES AND DEUTROSTOMES:

Coelomates animals are distinguished according to the fate of blastopore into two groups:
a) Protostomata:
In this group blastopore eventually becomes the mouth of adult. Examples include phyla
Annelida, Mollusca and arthropoda.

b) Deutrostomata:
The blastopore develops into anus and a second opening which later develops to form
mouth. Examples include Echinodermata and chordates.

PHYLUM PORIFERA
INTRODUCTION:
Porifera derived from two “Latin” words “porous” and “fera” means, “pore bearing”. This
phylum includes about 5000 species. They are the simplest living organisms usually called
“sponges”.

IMPORATANT CHARACTERS:
Some of the important characters of this phylum are given below.

i) Occurrence:
The animals of this family are the metazoans i.e. multicellular animals. They are aquatic
animals present in both marine and sea water whereas 150 types live in fresh water.

ii) Nature:
They are sessile (immoveable) i.e. do not move. They are present in water and attached with
other solid substrates like stone and rock.

iii) Structure:
Their body contains a lot of pores which are called Ostia through which water enters the
body. The largest pore is known as osculum, through which water is discharged out. Tissues
are absent in their body due to the intracellular gaps.

iv) Symmetry:
Their body consists of irregular; up and down, short and large structure therefore they are
asymmetrical animal i.e having no plane of symmetry.

(v) Composition Of Skeleton:

They have a thick and solid exoskeleton. Their body skeleton composed of proteins, CaCO3
and silica (SiO2). The skeleton has spiny and needle like structures projection called spicules.
Spicules constitute the skeleton of sponges.

(vi) Fusion of Gametes:

Their gametes are fused inside their body, hence they possess internal fertilization. After
fertilization zygote develop into free-swimming amphiblastula larva. It is attached to the
bottom, then develop into a new sponge.

(vii) Body Cavity

Body cavity is the hollow region in which digestion occurs basically. Their body cavity in
known as spongocoel. Specific cells called choanocytes produce their body cavity.

LIFE PROCESS:
(i) Nutrition
They are basically the filters feeders, they use plankton (the small fragments of food particles
which are present in water) as a food they also use bacteria and organic matter as their food
of filtration.
(ii) Mode Of Life :
These animals do not have head, mouth and alimentary canal. They do not have nervous
system, respiratory system and excretory system. Their respiratory system and excretion
takes place by diffusion.

(iii) Reproduction:
They are reproduced by asexual as well as sexual methods.
-Asexual:
A sexual reproduction takes place by fragmentation, budding, regeneration, and gemmule
formation.
-Sexual:
The reproduction in which both sexes are involved. Sponges are hermaphrodite, but some
are unisexual. Sperms are transferred into another sponge where fertilization occurs.

TYPES OF SPONGES:
Spongocoel may be single or divided into many chambers. There are three types of sponges
on the basis of their body cavity.

(i) Ascon Type:

Spongoceol consist of single cavity.

(ii) Sycon Type:

Spongocoel divided into secondary chambers.

(iii) Leucon Type:

The spongocoel divided into secondary and tertiary chambers.

CLASSIFICATION:
This phylum is classified into three classes.
(i) Calcaria
The exoskeleton is composed of CACO3 or lime crystals e.g. Ascon

(ii) Hexactinellida:
The exoskeleton is composed of siliceous spicules with 6-part geometry, e.g.: Euplectella
(iii) Demospnge:
Exoskeleton is composed of protein as well as spicules, e.g.: Spongilla

CELLULAR FUNCTION OR SPECIFIC CELLS:

They have specified cells for various functions like:

i. Porocyte:
Porocyte cells makes pores in their body because of these cells their body is perforated.
ii. Pinacocyte:
These are the contractile flattened cells forming the epidermis.
iii. Choanocyte:
These are flagellated cells make the body cavity called spongocoel.
iv. Gonocyte:
These cells help in reproduction of poifera.
v. Gastrocyte:
These are the cells, which help in digestion.

PHYLUM CNIDARIA
INTRODUCTION:-
The animal of this phylum are morphologically least complex metazoan. Phylum cnidarians
includes about 9000 species is also commonly called coelenterate.
 IMPORTANT CHARACTERS:-
Some of the important character of this phylum are described below:-

1- Habitat:-
They are simple aquatic animals. Mostly, they are marine, such as jelly fish, sea Anemones,
Corals etc, and only few animals are found in fresh water e.g. Hydra.

2- Symmetry:-
Some of them have radially symmetrical body e.g.: Obelia and some of them have bilateral
symmetrical like jelly fish. Some of these animals are sessile and some of them are motile
(they poses hydrostatic skeleton which provides turgidity to their body.

3- Body Cavity:-
Inside the body, digestive cavity is present called enteron or coelenteron. It opens to the
outside by a single opening mouth. Due to the presence of a hollow cavity, they were
formerly known as Coelentrates.

4- Diploblastic Organization:-
They are diploblastic i-e their body wall consist of two layers the outer layer is epidermis
ectoderm and inner layer is gastro dermis (endoderm), which is present along the body
cavity. Between these two layers a non-cellular gelatinous layer is found called mesoglea.

5- Defensive Organs:-
The mouth is surrounded by finger like structures, called tentacles or oral arms. These
tentacles contain special cells known as cnidoblasts. These cnidoblasts have capsule like
bodies, the nematocysts. These are the organs of offense and defense. Due to the presence
of cnidoblasts they are called cnidarians.

6- Life Style:-
The animals are of two types, one is polyp and other is medusa. The polyp form is attached to
the substrate at one end and provided with tentacles around it e.g.: Sea Anemone. Muscular
tissues are present in tentacles. The medusa animals are free swimming and they are not
attached to any object e.g.: Jelly fish.

7- Nutrition:-
Cnidarians are usually carnivorous but some of them also use planktons as a food. They
paralyze or kill their prey with the help of special stinging cells called cnidocytes.

8- Nervous System:-
The nerve cells do not form brain and spinal cord. They are present in the form of networking
for communication and co-ordination, so impulses are conducted in all directions more or
less equally.
Cnidarians are the first animals in Kingdom Animalia which possess nerve cells.

9- Mode Of Life:-
The cnidarians do not have proper respiratory, excretory and circulatory systems. All these
processes are performed by diffusion process through body surface.

10- Polymorphism:-
 They usually live independently but some live together to form a group or colony. In this
colony many individuals are physically attached together. This group formation is called
polymorphism.
In polymorphism polyp and medusa forms live together. The polyps obtain food material
and medusa takes part in reproduction.

11- ZOOID'S FUNCTION:-

In a group two or more different types of animals are present, called zooids. These zooids
collectively form a single species. The zooids perform different function such as:

i. Gastro Zooids:-
They take food materials.
ii. Gono Zooids:-
They are reproductive zooids.
iii. Dactylo Zooids:-
They are sensory zooids and they protect the animals.
In the polyp form the reproduction is asexual and in medusa the reproduction is sexual.

12- Reproduction:-
They are reproduced by sexual as well as asexual methods. Asexual reproduction is mostly by
regeneration and budding. Sexual reproduction also takes place in cnidarians by the fusion of
male and female gametes.

13- Alternation Of Generation:-

 They have special reproductive period called "alternation of generation" i-e: their life
cycle is completed in two stages:
-Asexual reproductive stage
-Sexual reproductive stage
 The asexual animal is polyp type by reproduction it produces two types of male and
female "medusa" individuals.
 The sexual male and female animals produces male and female gametes by their
fertilization zygote is formed.
 The zygote develops into a larva called "Planula Larva". This larva develops again into
a new sexual polyp. This process is called alternation of generation. e.g : Jelly fish.

14- Coral And Coral Reefs:-

Some cnidarians secret chemical substance, which forms a protective covering around their
body, these are called corals. They are of different shape and size. They are usually present in
warm water.

15- Phylogeny And Classification:-

Cnidarians are evolved from protoctista according to the phylogeny, but from cnidarians no
other phylum is evolved.
Phylum cnidarians is divided into three classes.

i- Class Hydrozoa: - e:g. Hydra , Obelia

ii- Class Scyphozoa:- e:g. Jelly fish
iii- Class Anthozoa: - e:g Sea Anemone, Corals.
 PHYLUM PLATYHELMINTHES
INTRODUCTION:
This phylum includes about 15,000 species. It is considered that these animals have evolved
from coelenterate like worm, which assembled a planula larva.

IMPORTANT CHARACTERS:
Their important characters are as follows:-

i- Occurrence:-
They are metazoans i-e multi cellular animals, mostly aquatic.
They are found in both fresh water as well as salt water or on dry places. Some of them are
segmented and some are unsegmented.

ii- Symmetry:-
They have a soft and flattened body on both sides, so they are called flat worms.
Platyhelminthes are the least complex animals. They are bilateral symmetrical animals.

iii- Triploblastic Organization:-

They are triploblastic i-e their body consist of three layers, the outer most layer is called
ectoderm, the middle is known as mesoderm, and the internal layer is called endoderm.

iv- Alimentary Canal:-

They have a single gastro- vascular cavity (alimentary canal). In some animals this cavity is
branched and opens to the outside by mouth only plasma. E.g. some animals do not have
gastro-vascular cavity such as cestodes (e.g. Tape worm).

v- Skeleton And Coelom:-

They have a soft body without bony or tough skeleton, but hydrostatic skeleton is present. A
true body cavity (coelom) is not found so they are acoelomate animals (without coelom).

vi- Movement:-
The movement takes place by the contraction and relaxation of their muscles.
Cilia also help in taking their body from place to another.

vii- Adhesive Organs:-

They are usually free living animals but few species are either ectoparasite or endoparasites
of animals to which they remain attached by their special adhesive organ, the hooks and
suckers. Which are used to suck the food material of the hosts.

viii- Sensory Organs:-

They have a special sensory organ called photoreceptors or sensors. Which are also known as
eyespots because they work to sense the amount of light and the coverage of favorable
condition.
ix- Mode Of Life:-
Respiration takes place by diffusion through the body surface. Blood vascular system is not
present. The transportation also takes place by diffusion. They have a double nerve codes for
the control of nervous activities.

x- Digestive System:-
They possess intra cellular digestion which is performed by diffusion. They have branched
canals in their body for the distribution of food to all the parts of the body.

xi- Excretory System:-

The excretory system consists of fine-tube like bodies, which are formed, in the form of a
network in their body. These tubes open to the outside by small pores. On the inner ends of
these tubes special cells are present called flame cells. These cells absorb excretory products,
which are discharged out of the body through the pores, called nephridiopores.

xii- Parasitic Life Cycle:-

The parasitic animals are either ectoparasite or endoparasites. Some parasitic animals
complete their life cycle in the body of one host, they are called monogenic. Some animals
complete their life cycle in the body of two hosts, they are called digenic.

xiii- Reproductive System:-

They reproduce by sexual as well as asexual methods. Fertilization is internal, but always
sperms of one animal are transferred into another animal. Some of them are hermaphrodite
i-e, male and female reproductive organs are present in the same body. Their fertility rate is
very high.

xiv- Support And Locomotion:-

They do not have bony skeleton, "Hydrostatic skeleton" is present to
provide support and turgidity to their body. The flat worms have only longitudinal muscles.
Circular muscles are not present. So, they can only bend or swim poorly.

xv- Reproduction:-
They usually possess sexual reproduction. They are hermaphrodite but in some
species sexes are separate (dimorphic). Their larva is known as "tornaria". No class is evolved
from this phylum. Their fertility rate is so high.

PHYLUM ASCHELMENTHES NEMATODES (ROUND WORMS)

INTRODUCTION:
The nematodes are called round worms; they are the most widespread and abundant
animals on earth. On this phylum 20,000 species have been identified.

IMPORTANT CHARACTERS:
Some of the important characters of this phylum are described below: -

1. Occurrence:
They are mostly internal or endoparasites but some of them also found in moist soil.
Nematodes are also present in the decaying body of plant and animals.
 2. Symmetry:
The body is without segments, elongate and round bodies. It is covered with a tough cuticle.
The anterior and posterior ends are thin and pointed. They have bilaterally symmetrical body.

3. Body Plan :
The body cavity is the primitive cavity, called pseudocoel. It lies between the body wall and
the gut wall. The pseudocoel is considered as false cavity. They are monogenic in nature.

4. Presence Of Blood:
They have a proper blood along with hemoglobin. They possess close type blood circulation.
They are cold-blooded i-e, of various body temperatures. Blood transport material within
their body.

5. Support And Locomotion:

They do not have skeleton, "Hydrostatic skeleton" is present to provide support and turgidity
to their body. The nematodes have two types of muscles for locomotion and movement. The
outer muscles are circular and inner muscles are called longitudinal.

LIFE PROCESS (PHYSIOLOGICAL CHARACTERISTICS)

Respiratory And Excretory System:

Respiratory takes place by diffusion, through their moist skin. The layer on their skin in called
"cuticle". "Protonephradia" are present for excretion, which are the advance form of "flame
cells".

Digestion and Co-ordination:-

They have a well develop digestion system along with a mouth and anus. A simple straight
digestion canal is present where the extra cellular digestion occurs 'Brainganglion" is present
for the control and co-ordination of nervous activities.

Reproduction:-
They usually possess sexual reproduction. They are hermaphrodite but in some
species sexes are separate (Dimorphic). Their larva in known "tornaria". No class is evolved
from this phylum. Their fertility rate is so high.

Organization:-
They are triploblastic in nature. Their body wall is composed of 3 layers.

 Ectoderm:
The outer layer is called ectoderm. Outer tube is complex body wall being covered
over by non-living cuticle.
 Mesoderm:
Middle layer is known as mesoderm.
 Endoderm:
It is the inner most layer.

DISEASES BY NEMATODES:-
 1- ELEPHANTIASIS OR FILARIASIS (thread worm ):-
It is caused by threadworm; Wuchereia is transferred into the body of man from blood sucking
mosquitoes. It lies in lymphatic vessels. As a result of this disease, feet, legs, hands become
extremely swollen , therefore the disease is known as "Elephantiasis".

2- HOOKWORM DISEASE:-
The hookworm, Ancylostoma enters the body of man in the form of larva through the skin of
man and finally enters the intestine. It lives there as parasite.

3- ASCARIS DISEASE:-
Ascaris lives in the intestine of children, lives as parasite and uses the food of host body.
Examples:-
Their examples are Hook-worm, Ascaris, Filarial worm, pinworms and Guinea worms,
Trichenella worm.
Their range is from microscopic to 9 meters long. Males are shorter than females.
A female ascaris may produce as many as 2, 00,000 eggs per day.

PHYLUM ANNELIDA
Some of the important characters of this phylum are described below:-
1. Occurrence:-
They live on land, in moist soil, and some rare species are aquatic. Some species of
annelids are also ectoparasite and suck the blood of their host. e.g.: leech

2. Structure:-
They are commonly known as segmented worms (Anellus little ring). They have
elongate and segmented body. Their segments are externally ring like, these rings or external
segmentation is called metameric, because external segmentation corresponds with internal
segmentation and some of their organs are repeated in each segment.

3. Locomotion:-
They have setae without parapodia for displacing them from one place to another.
They also have muscles, which are of two type's circular and longitudinal muscles.

4. Digestive System:
Mouth and anus are present in their body. They have a well-developed digestion
system along with proper digestive organs like gizzard, mouth cellular. Enzymes are also
present in their body.

5. Body Plan:-
They have bilateral symmetrical body. They are triploblastic animal's i-e, the body
consist of three layers, outer ectoderm, middle mesoderm and inner ectoderm. They contain
fixed no of segments.

6. Respiratory System:-
They do not posses any special organs for their respiration. They simply posses
cutaneous respiration i-e, respiration takes place by diffusion through their moist skin.
Excretion and osmoregulation takes place by metanephradia.
7. Circulation Of Blood:-
They have a well-developed blood circulatory system of closed type with definite
blood vessels and many pulsatile hearts. Blood is usually red due to the presence of
hemoglobin. They are cold-blooded animals.

8. Body Cavity:-
Their alimentary canal is elongated and tube like. These animals posses a true coelom
(true body cavity). It lies between the layers of mesoderm. Due to the present of true coelom
they are called coelomates.
There is development of coelomic compartments in their body.

9. Co-ordination:-
The organ for the control and co-ordination in their body is brainganglion, which
consist of two parts. The larger part is called suprapharyngealganglia and the small is
subpharyngealganglia.

10. Partition Of Segments:-

They have external as well as internal segments. Their segmentation is called
metameric segmentation. The wall which provides the partition to segments is called septum
and the plural is sept.

11. Feeding:
They usually use fertilizing soil as a food and add nitrogenous wastes into it. Some
species have special adhesives organs called suckers through which they suck and absorb the
blood of the host body, they are ectoparasites. e.g. leech

CLASSIFICATION:
This phylum is divided into:
i. Class Polychaeta
ii. Class Oligochaeta
iii. Class Hirudinea

12. Reproductive System:-

Majority of these animals are hermaphrodite .Asexual reproduction also takes place by
regeneration. In annelids some chambers fused together to form a special reproduction zone
called "clitelium". Glands are present in clitelium. Their larva is called "trochophore".

13. External Features:-

Eyes are usually present. They have hydrostatic skeleton. Some of them also contain
head is known as prostomium.

14. Importance:-
Earthworms increase the soil fertility by adding nitrogenous substance into it. They
are also used to prepare medicines. They are also used in research work and dissection in the
laboratories. During fishing they are used as a food of fish.

CLASSIFICATION OF PHYLUM ANNELIDA:

Phylum is divided in to three classes mainly on the bases of numbers and type of locomotors
Organs.
 i. CLASS POLYCHAETA:

1. Polychaetes usually free living active swimmers sedimentary filter feeding furunculous
forms.
2. They are mostly marine having a pair of a lateral flap like fleshy lobes the parapodia on
each segment of the body
3. Each par podium also has a bundle of bristles called setae or chaetae.

4. Sexes are separate.

5. Development passes through a Trochophore larval stage.

Examples: Sabula (peacock worm) and Neries (clam worm).

ii. CLASS OLIGOCHAETA:

1. They are usually terrestrial, free living, burrowing form without parapodia but with few
setae per segment arranged in a ring.

2 .All are hermaphrodite

.
Examples: Pheretima the common earthworm.

iii.CLASS HIRUDINEA:

1.In these setae and parapodia, both are absent, instead an anterior and a posterior suckers
are present for blood sucking and attachment.

2. Some are free living predators where as others are ectoparasites of vertebrates and
invertebrates.

3. They live usually in fresh water and are all hermaphrodite

Examples: Hirudinaria (Indian leech ).

PHYLUM MOLUSCA
INTRODUCTION:-
They have soft boded animal most have an external and some have an internal
shell. This is the second largest phylum after arthropoda. They have proper shell around their
body for protection.

IMPORTANT CHARACTERS:-
Some of the important character of this phylum is described below:-

1. Occurrence:-
The animal of this phylum are found in fresh water as well as marine water.
Very few are terrestrial, where they live in moist soil. This phylum includes slugs, oysters,
calms and squids etc.

2. Body Plan:-
 They have soft and unsegmented body with bilateral symmetry and organ system
organization. They are triploblastic organisms i-e their body consist of three layers, outer is
ectoderm, inner is endoderm and middle is mesoderm.

3. Locomotion:-
Appendages are not produced from their body. They locomote with the help of their
muscles and muscular organs (tentacles). From the lower side of their body a special
structure "foot" is developed, which helps in feeding, sensation and locomotion.

4. Digestive System:-
They have well developed digestive system with proper and better digestive organs.
Alimentary canal is in the form of a straight or coiled tube with mouth and anus at the
opposite ends.

5. Respiration:-
They also posses better respiratory organs for respiration. Gills or lungs are used for
respiration. In aquatic animals, gills and in terrestrial animals poorly developed lungs or
rudimentary lungs are present.

6. Presence Of Radula:-
In some animals a special structure is produced in their mouth, called radula. It is used to
scrap food particles from rocks or to make holes in the shells of other mollusk. It is also used
for tearing and pulling of food.

7. Co-Ordination:-
On the upper side of their body braingnglion is present for control and co-ordination.
While the networking of nerve codes are too present in the lower parts of body.

8. Blood Circulation:-
They have a well developed blood circulatory system. Which is of open type, but
the cephalopoda have closed type of circulatory system. Heart is also present.

9. Life Style:-
They have a proper and particular shell on their body for protection. The upper layer of
body is called mantle, it produces shell. The head is distinct. Mouth, eye and tentacles are
present on the head. Excretion is by kidneys.

10. Reproductive System:

They possess sexual reproduction. Reproductive organs are found either in the same body or
in separate bodies. Fertilization is in water. After fertilization the egg develops into a larva
which is changed into an adult. The larva is of trochophore type.

11. Special Glands:-

Some of them have a specialized ink gland which secretes a smoky substance for the
defense from other animals. It also helps them in hunting their prey.

12. Pearl Formation:

In pearl oyster mollusks, pearl formation takes place, when a foreign particle enters the shell
of animal. From the epithelial layer of mantle CaCO3 material is secreted and its layers are
formed around the foreign particle, due to this process it is changed into a pearl.
 13. Economic Importance:

i. Mollusca are used in Palaentological study.

ii. Many varieties of these animals are used as food material.
iii.Their shells are used to make decorative pieces.
iv. In the shells of mollusks pearl formation takes place e.g. Pearl Oyster. These
pearls are placed in jewelries. In Japan there is a culture industry.

14. CLASSIFICATION:
Although phylum Mollusca is usually divided into six classes:
i. Monoplacoplora e.g. neopline
ii. Amphineura e.g. chitin
iii. Scaphopoda e.g. dentalium
iv. Gastropoda e.g. Pila
v. Bivalvia e.g. Unio
vi. Cephalopoda e.g. Sepia

CLASSIFICATION OF PHYLUM MOLLUSCA:

Phylum Mollusca is usually divided into six classes.

i.Monoplacophora
ii.Amphineura
iii.Scaphopoda
iv.Gastropoda
v.Bivalvia
vi. Cephalopoda

Of these only three are discussed mainly.

1. CLASS GASTROPODA:
i- This is the largest class of Mollusca.
ii- They are mostly marine, though some live in fresh water and still others are terrestrial.
iii- Many of them become, secondary asymmetrical by the twisting of visceral mass at 180C by
phenomenon called torsion.
iv- They have a prominent head and a broad muscular foot developed on the visceral mass.
v- External shell may be present or absent, whenever present it is usually spirally coiled
Example: Pila, Snail, and Slugs.

2. CLASS BIVALVIA:
i- This group is the second largest class of phylum Mollusca.
ii- Their bodies are enclosed in a shell which consist of a right and left piece.
iii- The muscular foot in ventral and laterally compressed suited for creeping and burrowing in the
soft mud or sand.
iv- Bivalves are both marine and fresh water forms.
Examples: Unio, Mytilus and Pearl oysters.

3. CLASS CEPHALOPODA:
i. Cephalopods are all marine and exhibit a high degree of development.
 ii. Foot in cephalopods is transformed into suckers bearing tentacles and arms.
iii. It is present in a ring round the mouth.
iv. Some have an external shell e.g. Nautilus.
v. Some have an internal shell e.g. Sepia and Loligo.
vi. Some have no shell. E.g. octopus
Examples: Octopus (devil fish), Sepia (uttle fish), Loligo (squids).

PHYLUM ARTHROPODA
INTRODUCTION:
Arthropoda is the largest phylum of animal kingdom. They are found everywhere in the world
where the life can exist.
Preface: Greek Arthros = jointed Podo = food.

CHARACTERS:
Some of the important characters of this phylum are as:

1. Occurrence:
They are found every where on the earth wherever the life is possible. They are aquatic,
terrestrial parasites and they are found even in the oil-wells.

2. Exoskeleton:
Their body is covered with an outer covering, called exoskeleton. It is made up of protein or
chitin. It is non-living and as the animals outgrows it is shed and new one is formed. This
process of regular changing over the skeleton and formation of the new one is called
“Moulting” and “Ecdysis”.

3. Structure:
They are metamerically segmented i.e internal segments are absent. They have bilateral
symmetrical body and are triploblastic. Their body is divided into head, thorax, and abdomen.
In some animals head & thorax fused together to form “CEPHALOTHORAX”.

4. Locomotion:
From the side of their body jointed legs or appendages are produced. The antennae, jaws,
legs are in pairs. The muscles are jointed appendages work together and perform many
functions, such as walking, swimming etc. Wings are the flying organs, help in fast and easy
movement of insects to other place.

5. Blood Circulation:
They contain white blood due to absence of Haemoglobin. Their blood circulatory system is
of open type i.e, blood vessels are absent and the blood flows through out the body.

6.Body Cavity:
The body cavity of these animals is known as haemocoel, because the blood flows through it.
The true body cavity coelem is very small and contains reproductive organs.

7.Digestion:
They have a well developed digestive system with better digestive organs and a tube like
structure, which extends from mouth to anus. Jaws are also present in their mouth but teeth
are absent.

8.Respiratory System:
Respiration takes place through gills in aquatic forms, but trachea are used as respiratory
organs in terrestrial forms like insects and by book lungs in scorpion.

9.Sensation:
Nervous system consists of brain in the anterior region (head) and double nerve codes in the
lower region of the body. They have compound eyes with mosaic vision. A pair of antennae is
also present to detect their food or enemy. It works as a sensory organ.

10.Excretion:
In insects and other animals excretion takes place through malpighian tubules. In some
animals green antemmary glands are the excretory organs.

11.Reproduction:
They posses sexual reproduction. Sexes are formed in separate bodies. Fertilization is
internal. Development takes place by metamorphosis. It is the process of development from
egg to the adult stage. It is of two types:
i. Incomplete metamorphosis.
ii.Complete metamorphosis.

In complete metamorphosis:
In this process egg is directly changed into new individual which is similar to the adult, called
nymph. It develops and becomes larger and mature, then finally changes into an adult. E.g.
cockroach.

Complete metamorphosis:
In this process different stages are present.
i.Egg
ii.Larva
iii.Pupa
iv.Imago.

IMPORTANCE OF ARTHROPODS:
Arthropods are of great economic importance. Their importance is as follows:

1. Pollination:
The insects of group arthropods help in pollination.
2. Source of Food:
They are the source of food of many animals and carnivorous plants.
3. Apiculture and Sericulture:
Farming of honey bees (apiculture) and silk worm
(sericulture) are very common and useful.
4. Dangerous Aspects:
Scorpions are dangerous containing poison – glands.
5. Casual of Diseases:
Many insects cause diseases in birds and some insects also cause allergy in man. In human
beings they are responsible for transmission of Trypanosome, Plasmodium and Germs of
chorea etc.

13. CLASSIFICATION:
Phylum Arthropoda is divided into five classes:

1. Class Meristomata: (with mouth plates) e.g. limulus (king crab)

2. Class Arachnida: (spider like animals) e.g. Spider, Scorpion
3. Class Crustacea: (with carapace) e.g. Prawn, Crab
4. Class Myriopoda:( with many legs ) e. g centipedes
5.Class Insecta: ( with six legs ) e. g Mosquitoes

CLASSIFICATION OF PHYLUM ARTHROPODA:

Arthropod is divided into following classes.

1. Class Merostomata:
1. The mouth is surrounded by many small plates.
2. The animals are horse shoe shaped.
3. The body consist of cephalothorax and an abdomen
4. They have no antenna.
Examples: King crab (limulus) – considered a living fossil.

2. Class Arachnida:
1. They have four pairs of walking legs.
2. They respire by the help of book lungs, trachea or general body surface.
3. They are comparatively large and posses a sting at the end of their narrow segmented
abdomen.
3. They are predators.
4.They posses silk glands which secrete a protein that on exposure to air forms silk threads
used in building nest and webs for trapping the preys.
Examples: Scorpions, spiders.

3. Class Crustacea:
1. They are marine, fresh water and even terrestrial creatures.
2. They possess two pairs of antennae, a pair of mandibles and two pairs of maxillae around
their mouth.
3. Their body is divided into head, thorax and abdomen.
4. In prawn head and thorax becomes fused to form cephalothorax which is covered over by
a single plate of exoskeleton called carapace.
5. Their appendages are modified for walking, swimming, feeding, respiration and as
accessory respiration structures.
6. They have usually five parts of walking legs.
7. Some are parasite e.g. Sacculina
Examples: Prawns, shrimps and lobsters.

4. Class Myriopoda:
1. These are terrestrial arthropods leading a hidden life in the soil
2. Their body consists of a head and a very long trunk consisting of many similar segments.
3. The head bears a pair of antennae and trunk is provided with paired lateral appendages.
4. This class includes centipedes with one pair xand millipede with two pairs of appendages
per segment

5. Class Insecta:
Insect have become the most successful group because they have evolved certain characters
some of them are given below:

GENERAL CHARACTERS:
1. Occurrence:
Insects are found everywhere in the world from low land up to the tops of Himalayas and
from hot springs to Antarctica temperature of 65C. They are even found in the oil wells.
Some of them are also aquatic.

2. Locomotion:
They have three pairs of jointed legs on their thorax which help them in easy and fast
movement. A pair of antennae is also present for the search of their food.

3. Exoskeleton for Protection:

They have a thick exoskeleton made up of chitin or proteins. There is a process of regular
changing over a skeleton called moulting and ecdysis. This exoskeleton protects the insect
from outer environment.

4. Presence of Wings:
Some of them also have wings for fast movement. There are two groups of insects

Pterigota: They have wings, so they can fly.

Apterigota: They don’t have wings so they can’t fly.

5. Mouth Parts:
Mouth parts are modified according to their function, such as

i. Biting and Chewing type (e.g. cockroach)

ii. Piercing and Sucking type (e.g. mosquito)
iii. Chewing and Lapping type (e.g. honey bee)
iv. Sponging type (e.g. housefly)
v. Siphoning type (e.g. butterfly)

6. Circulatory System:
They have developed circulatory system, but blood is not red due to the absence of
hemoglobin. Digestive system is also well developed. There is open type of circulatory
system.

7. Reproduction:
They reproduce sexually as well as asexually. Some times sexual reproduction is not found
and egg without fertilization change into zygote, the process is called parthenogenesis.
8. Metamorphosis:
The development of insects after hatching from egg into adult stage involves considerable
growth and in some cases drastic morphological changes. The entire post hatching
development is termed as metamorphosis.

9. Social Life:
They mostly lead independent life; a few ants, termites and honey bees live in large colonies,
with a marked division of labour and are called social insects.

10. Carrier of Disease:

Many insects are harmful to mankind. Mosquitoes and flies transmit many diseases Malaria,
Dysentery, Cholera etc. Fleas are ectoparasites. Rat fleas transmit plaque disease in man.

Examples: Honey bee, Mosquito, Butterfly Cockroaches, Housefly, Moths, Silver fish.

PHYLUM ECHINODERMATA
INTRODUCTION:
The animals of this phylum are called spiny skinned animals.

Examples: starfish, brittle star, sea urchin, sea cucumber, sea lily and feather star are
included.

IMPORTANT CHARACTERS:
The important characters of this phylum are as follows.

1. Habitat and Symmetry:

They all are typically aquatic animals, present in marine water. They may
be predators, scavengers or carnivores. No parasitic form is known. Their larva has bilateral
symmetrical body but adult is radial symmetrical. These animals usually have five parts or
arms, so they can be considered as pent radial or pentamerous animals.

2. Skeleton:
They have calcareous skeleton. The calcareous plates also bears spines, called spicules, so the
phylum is called Echinodermata. The spines may be short in sand dollars or long as in sea
urchin. They are motile but some rare species are also sessile.

3. Body Plane:
Their body is unsegmented without head, brain and eyes. They are triploblastic i.e their body
consist of three layer outer ectoderm, inner endoderm and middle mesoderm. They contain
true body cavity, the coelom. It is divided into five parts.

4. Unique Features:
In their body a water vascular system is present. The water flows through the canals, which
contain tube feet. These tube feet are used for movement, capturing food, respiration and
sensory perception. The water enters the body through a plate like structure called
medreporite. It has small pores.
 5. Mode of Life:
Digestive, Respiratory, Circulatory and Nervous system are not well developed. Blood and
Excretory system are absent. Usually, they are carnivorous. Mouth is present at the center of
the body. Respiration takes place by skin.

6. Reproduction:
Regeneration process is very common in which lost parts of the body are developed again. In
sexual reproduction sexes are separate and fertilization is external. Developed is indirect.
Zygote is changed into bipinnaria larva.

7. Affinities of Echinodermata:
Echinoderms have embryological similarities with chordates and hemichordates such as
pattern of cleavage, blastulation, gastrulation and blastopore formation. The bipinnaria larva
of echinoderms have many structural similar characters like tornaria larva of hemichordate.
So this phylum has great relationship with hemichrdata and chordata. Echinoderms evolved
as side branch from common pipleura like ancestor which give rise to hemichordate and
chordate.

8. CLASSIFICATION:

*Class Asteroidean: e.g. star fish

*Class Echinodermata: e.g. sea urchins and sand dollars.
*Class Ophivroidea: e.g. brittle star
*Class Holothuroidea: e.g. sea cucumber
*Class Crinoidea: e.g. father star

PHYLUM HEMICHORDATA
The animals of this phylum are also called acorn- worm. This is a group of worm like animals
which are found in marine water.
Some of the important characters of this phylum are as:

GENERAL CHARACTERS:
1. Occurrence and Symmetry:
They live in shallow water or burrows in sand or mud of sea bottom. They all are soft bodied
unsegment animals with cylindrical structure. They have bilateral symmetrical body.

2. Body Plane:
Their body consist of three parts proboscis, collar and trunk. The proboscis is the upper small
conical muscular part. It is connected to the collar by a small stalk. Below the collar trunk is
present. It is long, cylindrical and worm like. They are triploblastic animals.

3. Nutrition:
Just above the collar mouth is situated. The food particles are attached to the proboscis
which move towards the mouth by the help of cilia and then enter into it. The animal’s feeds
on organic matter present in the sand. Their body coelom is divided into three chambers.

4. Mode of Life:
Just behind the collar pharynx is present. It has gills slits which help in respiration. They have
open type of blood circulatory system. They also contain dorsal and ventral nerve cord which
are connected with each other by transverse rings. In their body from the digestive cavity to
the proboscis cavity a rod like structure is present, called stomochord.

5. Reproduction:
Senses are separate. The blastopore develops into anus, so hemichordates are
deutroetomes. Fertilization is external. The zygote forms a larva, termed as tornaria larva. It
develops into an adult animal. This larva resembles to the larva of echinoderms. It indicates
the evolutionary relationship between two phyla e.g. Blanglossus gigas Saccoggssus
kowalewskii.

PHYLUM CHORDATA
The important characters of phylum chordate, which are different from other animals, are
as:

DIAGNOSTIC CHARACTERS

1. Notochord:
It is a solid flexible skeletal rod like structure present in the dorsal region of their body. It
extends the length of the body and present in few chordates, through their life where as in
most of them it is surrounded and replaced by a vertebral column.

2. Dorsal Nerve Cord:

They have nerve cord in their dorsal region, while the invertebrates have nerve chord in their
ventral region. This nerve cord is tube like hollow and fluid filled. In craniates group it consists
of brain and spinal chord.

3. Pharyngeal Gills Slits:

They have pouches in pharyngeal region called pharyngeal pouches. These pouches open
into the outside by gills slits. These organs help in respiration. These pouches may be present
either in embryonic stage or throughout the life.

Phylum chordate is divided into two groups:

1. Acraniata or Protochorda.
2. Craniata or Vertebrata.

1. GROUP ACRANIATA:
The major characters of the group are:

*Absence Of Cranium:
They are the simple chordates without brain box (cranium) hence their brain is not
prominent.

*Notochord:
They have a solid and flexible skeletal rod-like structure in the dorsal region of their body
called notochord. In these animals notochord doesn’t changes into vertebral column.
 Group acranaiata divided into two sub-phylum.
i. Urochordata.
ii. Cephalochordates.

 SUB PHYLUM UROCHORDATA:

Some characters of this phylum are: They are also known as tunicates or ascidians.
1. Chordate like Characters:
They have larva with typical chordate structures. The larva has nerve cord and notochord in
its tail. In the pharynx gills slits are present. When the larva is changed into an adult stage the
tail regenerates and hence notochord disappears, only gills slits are present in adult stage
due to the presence of notochord in the tail they are called as urochordates.

Habitat: They are marine mostly sessile living attached to rows, ships bottom and other
substrates.

2. Nature:
They all are marine and sessile but larva is motile in nature. They have filter feeding system
i.e, the food enters the body along with water. The food remains in the body while water is
entered out.

3. Tunic Enclosed Body:

Their body is enclosed in a sac like structure called tunic, so they are called tunicates. The
tunic is provided with two openings an incurrent or buccal siphon for the entrance of food
and water and the other excurrent siphon for the excretion of water and wastes products.

4. Life Style:
They have heart with blood vessels. So, they posses closed type blood circulatory system. As
the larva reaches the maturity it attaches to the sea bottom and undergoes retrogressive
metamorphosis by losing its tail and most of the chordates structures.

5. Reproduction:
Reproduction is by sexual as well as sexual method. Asexual reproduction is by budding. In
sexual reproduction the larva is tadpole like, which develops into an adult form. Many species
of herd mania are found in our seas.

 SUB PHYLUM CEPHALOCHORDATA:

It is a small sub phylum based on two genera, Asgmmetron and Branchiostoma commonly
known as Amphioxus.
1. Occurrence:
They all are marine with the cylindrical structure. Their body is segmented with its both ends
pointed. The segments are called myomeres. They have dorsal, ventral and caudal fins for
swimming but not in pair forms.

2. Mode of Life:
They don’t have proper head and appendages. Brain, eyes and ears are also absent in their
body. Notochord is present whole the life, from the anterior region to the tip of the tail. The
pharyngeal region is large and contains many pairs of gills slits.
 3. Sensation and Feeding System:
Never cords are present all over the body. They posses closed type of blood circulatory
system. They have filter-feeding system. Water enters through mouth and comes out
through an opening called antriopore. They are usually herbivorous.

4. Excretory System:
The excretory organs are protonephradia. They have cilia and open into the atrium. All the
excretory products are discharged out through the antriopore.

5. Reproduction:
They posses sexual reproduction and sexes are found in separate bodies. Fertilization is
external.

2. GROUP CRANAIATA:
Important features: (with cranium and vertebral column).

i. Presence of Cranium:
These are the chordates in which brain is protected inside a bony or cartilaginous part of skull
called cranium. They have high-developed nervous system with brain, spinal cord, cranium
and spinal nerves.

ii. Habitat: Vertebrates are the most advance animals in their structure and behavior.
Vertebrates are present in all types of habitats on the earth.

iii. Vertebral Column:

In these animals notochord is changed into vertebral column hence they are called
vertebrates. Cartilage is found in some invertebrates, such as Mollusca, but bone is unique to
vertebrates, mainly consisting of hydrated calcium, phosphate minerals in protein matrix.

iv. Blood Pumping Organ:

There is ventral heart behind the head, blood flows forward ventrally from heart then
through the gills or lungs and then upwards and backwards dorsally.

v. Excretory Organ:
They posses well developed excretory organ. There excretory organ are usually
kidneys, lie dorsally coelem, they comprise thousand of nephron units. They have paired
limbs by organ system.

CLASSIFICATION:
The group craniate is divided into sub phyla.
1. Sub phylum Agnatha.
2. Sub phylum Gnathostomata.

i- SUB PHYLUM AGNATHA:

Introduction:
These are the earliest known and most primitive vertebrate. Their mouth is without jaws.
This is a small group of vertebrates which includes only one class “Cyclostomata” hence
agnatha are commonly called cyclostomes.
 MAIN CHARACTERS:- These main features are as following:-
i. Occurrence and Diagnostic Characters:-
They are typically aquatic animals and are present at the depth of sea. As the
members of this group superficially resemble the fishes but lack the jaw, hence they are
known as “jawless fishes”. The absence of jaws is diagnostic feature.

ii. Body Plan:-

Their body is elongated. They have cartilaginous skeleton. Their skin is soft smooth and
without scale specialized features of lampreys includes the mouth and tongue, the
streamlined shape and pouched gills allowing a tidal flow of water over them. Their tongue is
spiny. In the mouth many rings of teeth are present.

iii. Blood Circulation:-

They have closed type of blood circulation. The heart consist of one atrium and one
ventricle. The heart pumps deoxygenated blood. They are cold blood animals hence can be
said poikilotherms.

iv. Feeding:-
They have rounded suctorial mouth. They are semi parasites on larger jawed fishes to
which they attack, rasping at the host flesh with a toothed tongue and horny teeth within
mouth cavity.

v. Locomotion and Respiration:-

They have dorsal and ventral fins for swimming but lateral paired fins are absent. They
are vermiform or cylindrical in shape and they posses many pairs of gills shits for respiration.
They have one nostril.

vi. Notochord and Vertrebal Column:-

The notochord does not change into a vertebrate column. It remain in its original
condition. They remain improper or vestigial eyes. A third functional median eye is also
present. They have a networking of nerves all over the body. Internal ears are also present.

vii. Reproduction:-
They posses sexual reproduction where fertilization is external. On fertilization eggs
hatch to form filter feeding. Ammocoetes larva, which lie in mud and then develop into adult
animals.
EXAMPLE:-
Hagfish Lamprey.

ii- SUB PHYLUM GNATHOSTOMATA:-

Diagnostic Characters
This is a large group of vertebrate which posses both upper and lower jaws- though teeth
may be present or absent.
Gnathostomata are divided into two super classes.
1. Super class Pisces.
2. Super class Tetrapoda.
 CLASS PISCES
Introduction:-
It is the largest group of chordates. More than half of the chordates are fishes, includes
about 25000 species.
The study of fishes is called “Icthyology”

Occurrence:-
They are typical aquatic animals present in both marine as well as fresh water.

Structure:-
They posses streamlined body (commonly spindle shaped). Mostly their body is covered
by dermal scales. Their body is divided into three parts.
i. Head
ii. Trunk
iii. Tail

Swimming:-
Their body is provided with paired fins which help them in swimming.

Respiration:-
Their respiration takes place through gills.
Super class pisces is divided into two classes.
i. Class chondrichthyes.
ii. Class osteichthyes.

CLASS CHONDRICTHYES:-

Introduction:-
This group also called “Elasmobranchi” comprises of marine fishes whose endoskeleton is
made up of cartilages, which are composed of chondriocytes.

i. Occurrence and Skeleton:-

There character are as follows:
They are typically aquatic animals mostly they are present in marine water. Their
endoskeleton is composed of cartilages while their skin contain an enormous number of tiny
sharp enamel coated dentils called “placoid scales”, which form their exoskeleton.

ii. Body Plan:

Their body is elongated and spindle shaped which is suitable for swimming. The skates and
rays live in the bottom of sea, so their body is flat. Nostrils are the smelling organs; they do
not open inside and are not involved in respiration. Eyes are without eyelids. They have sharp
sense of smell.

iii. Swimming:
 They have fins, a pair of pectoral fins, a pair of posterior fins two median dorsal fins and
caudal fins. They help in the locomotion and swimming. The caudal (tail) fins is heteocercal.

iv. Excretion and Mouth Plan:

Excretion takes place by well-developed organs called kidneys. The mouth is situated on the
under side of the head. It has rows of teeth. The lost teeth can be replaced continually.

v. Respiration:
Five pairs of exposed gills are present which open directly to the outside. They are not
covered by any covering or operculum. The water passes outside through the gills slits. Gills
are the respiratory organs.

vi. Circulatory System:

They are cold blooded animals (i.e of various body temperature) the heart is of primitive
type. It pumps only deoxygenated blood. The heart consist of two chambers one atrium and
one ventricle. The circulatory system is of closed type.

vii. Reproduction:
The sexes are separate and fertilization is internal. In some sharks ovo- viviparous
reproduction takes place in which the female sharks retain eggs within their bodies until the
partial development of young sharks.

Examples:
Sharks, Skates, Electric Ray (Torpedo) Dog Fish (scoliodon = small sharks)

CLASS OSTIECHTHYES
Introduction:
This group also called “Teleostomi” It is actually the largest class of chordates. It includes
about 20,000 species. In this class bony fishes are included. Their size varies from 1.5 inches
to 5 feet.

Important characters are as follows:

i. Occurrence:
They are typically aquatic chordates present in marine as well as fresh water in which mouth
opening is present at the anterior tip. They are found from shallow ponds to the deep dark
sea water.

ii. Skeleton:
Their endoskeleton is bony that is made up of bones which are composed of osteocytes.
While their exoskeleton is made up of thin body plates which are called cycloid or ctenoid
scales according to whether their outer edge is smooth or spiny.

iii. Structure:
Vertebral column is present with proper segments. Eyes are present with transparent
eyelids. Their body is divided into three parts.
i. Head ii.trunk iii. Tail
iv. Respiration:
Respiration takes place by four pair of gills. The gills slits are covered by a hard covering, the
operculum. They also contain an air bladder which is not used for respiration. It regulates
buoyancy i.e helps in swimming and as well as hydrostatic organs.

v. Locomotion:
They have a pair of pectoral fins a pair of pelvic fins, a median anal fin and caudal fin. All
these fins help in the swimming, balancing and changing the direction. Tail fin is homocercal
or diphycercal.

vi. Circulatory System:

They are cold blooded animals. Their heart have two chambered heart, one atrium and one
posses closed type blood circulation.

vii. Reproduction:
They posses sexual reproduction. Fertilization is internal, large no. of small eggs develop into
larva (fry) which metamorphosis in to adults.

LUNG FISHES

Introduction:-
A small group of zoogeographical important fishes called LUNG FISHES. They belong to the
order dipnoi of class osteichthyes.
Occurrence:-
Only three genera of such fishes are found in the world. They are found isolated, one type
each in South Africa and Australia hence called American lung fish. American lung fish and
Australian lung fish. Example: - Protopteuis.
Respiratory Organs:-
These fishes contain lungs which are the modified forms of air bladders. They respire by
the help of gut as well as, at times during drought period by lungs.
Signification:-
These fishes can survive without water for several months.

SUPER CLASS TETRAPODA:-

Essential Feature:-
In this class of vertebrates two pairs of limbs are present. Each limb has five digits, so
called pentadactyl limbs. These limbs are used for walking, running, flying for various other
functions, also used for offence and defense.
This super class is dividing into four classes.

CLASS AMPHIBIA
INTRODUCTION:
The animals of this class pas double life. (Amphibian= double life in Greek). They live in
water as well as on land. These are the first animals which migrated from water to the land
 and started their life and established themselves there. On land they got certain advantages
and also faced some problems.

ADVANTAGES ON LAND:
i. They escaped from struggle of life and competition.

ii. They got many better and stable places to live.

iii. They got better supply of oxygen. Lungs are their organs of respiration.

iv. They got limbs for locomotion.

ORIGIN OF AMPHIBIA:
The ancestors of amphibians are considered Rhipidistian. These are ancient bony fishes. In
these lungs were present and they also had bony endoskeleton with fleshy lobed fins. By the
help of these fins they were able to move from one dried pond to other water containing
pond. It is thought that amphibians are evolved from Rhipidistian.

IMPORTANT CHARACTERS:
The important characters of amphibians are as follows.

i. Occurrence: (Habitat)
The amphibians can live both in water and on dry land. They lay eggs in water where
they spend at least their early life. Hence, they have become partially aquatic and partially
terrestrial.

ii. Blood Circulation:

They are cold blooded animals (poikilothermic) i.e. their body temperature can change
according to the environment. The heart is advance than fishes. It is three chambered two
atria and one ventricle. It pumps both oxygenated and deoxygenated blood. It posses closed
type blood circulation.

iii. Skeleton:
This is the group of vertebrates which lack any sort of exoskeleton. They have bony
endoskeleton with strong back bone (vertebral column) and two pairs of limbs they help in
locomotion. No to chord is replaced by vertebral column.

iv. RESPIRATION:
They have three different methods of respiration.

 Pulmonary:
Respiration takes place by lungs. It occurs on land.

 Cutaneous Respiration:
It takes place by moist skin in water.

 Buccopharyngeal:
By buccal cavity on the surface of water.
v. Body Plan:
Their skin is soft, thin and moist. Scales, hairs and feathers are absent. Eyelids are present,
the eye contain tear glands to keep them moist during dry season. External ear is absent only
internal ear is present. They are carnivorous.

vi. Periods For Survival:

Amphibians are poikilothermic. Hence they can't bear extreme temperature during
winter they take rest in mud. It is called hibernation. During this period they become inactive
and use their internal reserve food. Some animals also take rest in summer it is called
aestivation.

vii.Reproduction:
They lay eggs in water. Fertilization is external. The zygote develops from a yolk of egg
and changes into tadpole larva. It respire by gills and feeds on aquatic plants. The larva
develops into an adult animal by metamorphosis.

AMPHIBIANS AS UNSUCCESSFUL LAND VERTEBRATES:

Amphibians are said to be unsuccessful land vertebrates because they failed to adapt
completely to the land environment because:

 Exoskeleton:
They are cold blooded and do not possess any exoskeleton so they cannot cope with extreme
temperature.
 Naked Skin:
They have thin naked skin which cannot prevent the continuous loss of water and hence
makes them vulnerable to desiccation.
 Fertilization:
Their eggs are small and without a shell. Fertilization is external.
 Mode of Fertilization:
They requires water for fertilization. Quantity of yolk is less and not enough for complete
development of the embryo. The larva hatches out at an early stage and undergoes
metamorphosis which passes through a gill breathing larval stage. Thus amphibians are
always in need of water.

CLASS REPTILIA
(To crawl and creep)

Reptilia is a group of 5000 vertebrate species with dry skin. They are the first successful
land vertebrates. Most of them are terrestrial such a lizard snakes but few of them also live in
water e.g. Crocodile, sea snake etc.

IMPORTANT CHARACTERISTICS:
Their characters are as follows:
i. Locomotion:
They crawl on land with the help of two pairs of limbs which are pentdactylous and
provided with horny claws. They are used for rapid locomotion. Snakes have no limbs, it
moves by the help of its muscles.
ii. Body Plan:
 Their skin is dry and covered by bony plates or scales. Their body has bony skeleton. They
have tail in the lower regain of their body. They have more or less water proof skin. Body is
divisible into head, neck, trunk and tail skin glands are absent.
iii. Respiration:
Gills are absent and respiration takes place by lungs throughout the life. Their excretory
organs are kidney. Alimentary canal terminates into cloacal aperture.

iv. Types Of Animals:

They are cold blooded animals (poikilothermic), i-e, their body temperature can change
according to the environment. Some of them also take rest during called hibernation.

v. Blood Circulation:
The heart consist two atria and one incompletely divided ventricle and thus separation of
oxygenated and deoxygenated blood is not complete. In crocodile the heart has completely
divided into two ventricles. They posses closed type blood circulation.

vi. Reproduction:
Fertilization is internal. They lay eggs which are large and covered over by leathery shells.
The development of embryo take place inside the shell, the yolk of egg provides energy. In
the egg protective membrane is present, called amnion. So they are called amniotes. They
also display regeneration (in tail of lizard).

REPTILES SUCCESSFUL LAND VERTEBRATES:

Reptiles is the first group of vertebrates fully adapted for life on dry places on land. Key to
their success on lands is:
 They do not have to go to water to reproduce.
 The mode of fertilization is internal and the amniotic egg with a leathery shell which is
impermeable to water but permeable to gases.
 They have developed kidneys to retain water and excrete concentrated urine.
 Their developed limbs and appearance of claws made them fit not only to move, dig and
climb but also to defend themselves against predators.
 Their developed lungs and hearts make possible the increased supply of oxygen for much
higher muscular activity needed for a much active life on land.

SNAKE

i. Introduction:
Snakes are the limbers lizards that on land crawl by the undulating movement of their body.

ii. Occurrence:
Some snakes are terrestrial and some are water living e.g. sea snake. They live in burrows.

iii. Body Plan:

The skull may be specialized to allow the swallowing of large prey. Snakes lacks eardrum.
Their eyes are without eyelids.

iv. Dangerous:
 Certain kinds of snakes are poisonous. The poison is produced in specially modified salivary
glands which are transferred into the body of prey through specially designed sharp and
curved teeth called fangs. The venom (poison) is a mixture of certain substances which
attacks the nerves and blood thus it usually causes death of the prey.

CLASS AVES
INTRODUCTION Birds are the most beautiful animals in the world. There are about 9000
species of birds and their study is called "Ornithology". Their variation in size is remarkable.
They range from 2gm West Indian humming bird to a 150 kg Ostrich.

DIFINITION OF BIRD:
"A bird can be defined as a feather covered bipedal flying vertebrate possessing wings."

IMPORTANCE:
The birds are most attractive animals in the world. They attract the people because of their
flight, colorful plumage (feathers), spring time songs, strange migrations, parental care and
considerable economic value in respect of food and as game animals.

IMPORTANT CHARACTERS:
The main characters are as follows:
i. Occurrence:-
They are typical terrestrial animals. Birds are present in large no's and live in different
habitats. They are among the most successful vertebrate due to their enormous, adaptation
to variety of environment and their distribution throughout the world.

ii. Skeleton:-
Their skeleton weight is much reduced owing to its hollow construction (pneumatic bones).
They have bony skeleton. Their bones are very soft, thin and hollow. Which help in an easy
flight of a bird.

iii. Circulatory System:-

Their blood circulatory system is well developed. The heart is advance. It consists of two atria
and two ventricles. The two ventricles separate the oxygenated blood from each other. They
are homeotherms hence their body temperature remains constant irrespective of the
temperature of the environment they are living in.

iv. Respiration:
They posses pulmonary respiration, hence it takes place by lungs. The lungs also contain air
sacs for the storage of air. These air sac system permits a unidirectional flow of air to lungs,
with blood vessels arranged to permit extraction of up to 90% of 02 from inspired air. This
respiratory system delivers a plentiful supply of 02 to its flight muscles.

v. Some Modification:
 Their mouth is modified into beak, teeth are absent. Their fore limbs are modifies into wings
and their hind limbs are modified into claws. The shape of beak and type of its feet and claws
tell about the habit and habitat of a bird.

vi. Unique Identification Character:

The unique and basic identifying character of birds is that their body is covered by feathers.
It not only serves as a protective insulating garment but also traps heat that’s why birds are
homeothermic.

vii. Nutrition And Mobile Neck:-

The shape of a beak is modified according to the function in different animals. Mostly they
are omnivorous but some of them are also typical carnivorous or herbivorous. The neck has
great mobility which helps in feeding, nest building, preening and defense.

viii. Voice Organ:-

They have a special sound producing organ, the syrinx instead of larynx present in other
vertebrates. It is present at the junction of trachea and bronchi. It is a cause of their spring
time songs.

ix. Nervous System:-

They have an advance nervous system. Brain is enclosed in a brain box cranium, which is
present at the upper region of their body. Eye orbits are very large and they posses very
sharp and keen eye sight of hearing is well developed.

x. REPRODUCTION:-
They are oviparous i-e, they are egg laying animals. The egg is covered over by a calcareous
shell. Fertilization is internal. They are amniotes animals. In the egg a protective membrane
amnion is present. They also hatch their eggs.

xi. Flight Adaptations Of Birds:

The birds have undergone a number of adaptations which helped them to meet the
requirement of a perfect flying animals.

1. Shape of the body:

The streamlined compact, spindle shaped body which offers less resistance to air is the
primary requisite of flight.

2. Loss of weight:
The hollow bones are light, strong and pneumatic. Teeth are lost and so are the tail
vertebrae. The urinary bladder, ovary and oviduct have also disappeared.

3. Wings:
Fore limbs are modified into wings.

4: Energy Requirements:
It is brought about by a rich oxygen supply to the tissues by a powerful heart and an extra-
ordinary respiratory system which is made efficient by the presence of air sacs

5. Maintenance of Body Temperature:

 Active muscular activity tends to rise the temperature of the body which is kept normal by
the ventilation action of air sacs.

CLASSIFICTION OF BIRDS:
They are classified into two sub-classes.
1. Sub class Ratitae (sternum raft keel)

2. Sub class Carinatae ( sternum with keel)

1. RATITAE:-

 Weight And Size:-

This sub class of birds includes the modern big sizes birds. These birds cannot fly because
they have comparatively heavy weight.

 Wings And Sternum:-

Their wings are either vestigial or rudimentary. They have a flat sternum without keel and
accordingly their flight muscles are poorly developed.

 Example:-
E.g. Ostrich, Kiwi, Rhea, Emi, Cassowary.

2. CARINATAE:-
They are all modern flying birds.

 Weight And Feathers:-

They are usually small in size, light weight birds whose wings are highly developed and
feathers of their wings have an interlocking mechanism.

 Sternum With Keel:-

Their sternum is provided with a crest like keel to accommodate the highly developed
pectoral flight muscles. The flying birds are distributed all around the world.
E.g. Peacock, Houbara.

CLASS MAMMALIA
PREFACE:-
The word “mammal” is derived from a Latin word which means “having mammary glands”.

ORIGIN:-
They are evolved from reptiles called "therapsida". They were nocturnal and burrowing
form. They were co-existed with dinosaurs and other reptiles for 50-200 million years when
large reptiles and dinosaurs disappeared.
IMPORTANT CHARACTERS:-
Their characters are as follows:-

i. Habitat:-
They are terrestrial animals, i-e, they found on land. They are adapted for life in a variety of
ecological niches from land and trees to water and even in the air. Some rare species are also
aquatic
E.g. whale and dolphin.

ii. Hair Covered Body:-

All the mammals have a protective and insulating hair cover on their skin. It is luxuriant in
most of the species, which helps to prevent the loss of heat and regulate the body
temperature. Their skins also possess sebaceous and sweat glands.

iii. Skeletal Structures:-

They have bony skeleton vertebral column. Their body cavity is divided into upper thorax
and lower abdomen by "diaphragm". They have seven cervical vertebrae in the neck region.

iv. Circulatory System:-

They have a well developed blood circulatory system of close type. Heart is completely four
chambered. The oxygenated and deoxygenated bloods remain separate from each other.
They are warm blooded animals (Homoiotherms). They have constant body temperature
which remains between 37C-40C.

v. RESPIRATION AND EXCRETION:-

Respiration takes place by lungs. The lungs have alveoli. A tidal flow of air into and out of the
lungs is assisted by a muscles diaphragm. Excretion takes place by kidneys.

vi. NUTRITION:-
Mammals are unique among animals in suckling their young's with nutritive fluid, the milk
secreted by special mammary glands. Their teeth are of different types, incisors, canine,
molars and premolars. So the teeth are called heterodont. They are also thecodont because
they are fixed in the gums.

vii. REPRODUCTION:-
They are viviparous i-e, produce young ones. Fertilization is internal; in most of the mammals
the fertilization of egg takes place in uterus. There is a cord between mother and developing
embryo called placenta through which food and oxygen are supplied. Mother take care of her
young ones after birth.

CLASSIFICATION:-
Class mammal is divided into three sub-classes "Protptheria", "Eutheria", "Metatheria".

SUB-CLASSES:

1. SUB-CLASS PROTOTHERIA:-
Introduction:-
This sub class contains the most primitive mammals being grouped in single order
"Monotremata", hence also called "monotremes". They are represented just 2 genera which
include only three species found only in Australia and "New Guinea".
General Characters:-
The animals of this class are egg laying (oviparous). They don’t have ear pinnae like reptiles.
Their body is covered by hairs. They have mammary glands to provide nourishment to their
young ones.
Connecting Link Between Reptiles And Mammals:-
They have cloacae i-e, the common opening of rectum and urogenital system, so they are
considered as connecting link between reptiles and mammals.
 2. SUB-CLASS METATHERIA:-
Introduction:-
It is also a relatively small group of mammals which contain a single order "Marsupialia"
represented by about 250 species, they are found in Australia, South America and North
America.
Reproduction:-
Marsupials are viviparous. They give birth to their young ones. Their eggs are not laid but
retained and fertilized inside the body of female. As the eggs do not contain enough yolk
which feed the embryo for the entire period of development, hence marsupials are born in
immature form.

Development And Nourishment:-

The rest of development of the new born tiny marsupial occurs outside the uterus in a special
bag like pouch that contains openings of mammary glands. Each baby attaches itself to a
nipple of mammary glands by its mouth. This pouch is called marsupiam and hence
metatherians are also called pouched or marsupial mammals.

3. SUB-CLASS EUTHERIA:-
Occurrence:-
This group indicates about 95% of the mammals which are wide spread and adapted to
almost each and every habitat on the earth.

Nourishment of Embryo:-
They are viviparous placenta mammals because the nourishment of young one takes place, in
the uterus of a mother, by special organ called placenta.

Function Of Placenta:- The placenta is a connection between the mother and its developing
young. Embryo receives oxygen and food from the mother’s circulation and discharge the
wastes into her blood through placenta.

Development Of Embryo:-
Embryo of placenta mammals is much more secure in the uterus where all the essential of
life are guaranteed hence they are born in a far more advance and almost completely
developed form.
Example:
 Small Euthariam:-
Squirrels, Rabbits, Hedgehogs, Rats, Scaly and eaters.
 Ungulates, Hoofed Animals:-
Sheep, cows, dogs, camels, horses, donkeys etc.
 Carnivours:-
Cats, dogs, lion, tigers.
 Omnivours:-
Bear, man, large placement mammals are elephants and whales.
 Flying:
Bat

MISCELLANEOUS
EDIBLE FISHES OF PAKISTAN:
 Introduction:-
Most of the delicious adible fishes Pakistan belong to:
Group= Craniata
Sub-phylum = Gnathostomata
Super class = pisces
Class = Osteicthyese

Edible Fishes:-
 Perches ( Pomfret)

 Hilsa (Pallah)

 Carps (rahu)

 Mackerels (surmai)

 Cat fishes ( khagga)

 Salmon (trout)

COELOM:
The bilaterally symmetrical animal phyla may be divided into three groups.
ACOELOMATA: are those who lack a body cavity such as Platyhelminthes.
PSEUDOCOELOMATA: are those who develop a body cavity but lack a true coelom, e.g.
Nematodes.

COELOMATA: These are all those who develop a true coelom. All animals belonging to phylum
Annelida to chordate are included in this group. In coelomates the mesodermal layer splits
open to contain a space that widens and eventually forms a body cavity in which digestive,
reproductive and other organs develop and are suspended.

TYPES OF BODY CAVITY:-

There are two types of body cavities.

i- COELOM: This is true body cavity and is lined by mesodermal layer. It is found in mammals,
birds and amphibians.

ii- PSEDOCOELOM: A psuedocoelom is though a body cavity, which also encloses the intestine,
but it is not formed by the splitting of mesoderm. Acoelomate animals have no such body cavity
at all. E.g.: Nematodes.

PARASITIC ADAPTATIONS OF PHYLUM PLATYHELMENTHES:-

It is worthwhile to be aware of parasitic worms because they cause disease, multiply rapidly
and are widespread. Many are spread due to poor sanitary condition. Hygienic living, careful
inspiration of edibles and through cooking of meat are the ways to avoid their infection.
Platyhelminthes have developed a number of adaptation which made them suitable for
their parasitic mode of life.
i- The thick body covering protect them against defense mechanism of host body
ii- The spins, suckers and hooks re developed for attachment. They replace the locomotory
organs, which are not needed by parasitic animals.

iii- Alimentary canal is reduced even absent as in taenia because of the availability of digested
food from host.

iv- Neurosensory organ are not developed due to their passive mode of life.

v- Reproductive system is very much developed. In taenia a set of reproductive organs is

present in almost every segment.

vi- Fertility rate is very high to cope with chances of danger from the defense mechanism of the
host body.

CHAPTER 11: BIOENERGETICS

BIOENERGETICS:
“In the living system the capturing and conversion of energy from one form to another and
its utilization in metabolic activities is called BIOENERGETICS.
Biological energy transformation obeys the laws of thermodynamics.

Role of ATP As Energy Currency:

Adenosine triphosphate (ATP) was first isolated by K.Lohmann in the early 1930’s. He
extracted it from muscle tissue. It is very important molecule of life as it is the major source
of energy of most of vital activities of organisms.
Properties of ATP:
It shows following properties:
1-ATP is produced by the oxidation of organic food in living organisms. It shows that ATP is
the common energy currency of cells. When cells require energy, they spend ATP for that.
2-ATP molecule is composed of adenine and ribose sugar with 3-phosphate groups.
3-ATP is also called a “high energy” compound because its phosphate groups are easily
removed.
4-The outstanding functional importance of ADP is that when it is hydrolyzed in the presence
of appropriate enzyme, it produces relatively large amount energy about 7.3kcal/mol on
conversion into ATP and an inorganic phosphate groups (Pi).
A–P--P P~P~ → A– P~ P + Pi + 7.3 Kcal/mol
Wavy lines between the phosphate bonds indicate the high potential (the use of wavy line
is for conveniences only it is not an actual means of energy).
5-ATP acts as a mediator, capable of receiving energy from one reaction and transfers this
energy to drive another reaction.
6-ATP plays role in several endergonic reactions (such as synthesis of proteins, lipids,
carbohydrates, active transport) and exergonic reaction (like anaerobic, glycolysis and
oxidative phosphorylation).
 Endergonic Reaction: is defined as a non-spontaneous reaction that requires a net
input of free energy.
 Exergonic Reaction: is a spontaneous reaction that occurs without external
intervention, release free energy and can therefore perform work.
7-ATP can also act as co-enzymes.
PHOTOSYNTHESIS:

“Photosynthesis can be defined as an aerobic process during which simple

carbohydrates are manufactured from CO2 and H2O in the presence of sunlight and
chlorophyll. Oxygen is released as a by product.”

Equation:

Reactants And Products of Photosynthesis:

1. Raw materials:
CO2 and H2O are the main raw materials of the process. In the vascular plants
water is absorbed by roots from the soil. The carbon dioxide is mostly absorbed by the aerial
parts.
2. Photosynthesis Products:
During photosynthesis CO2 absorbed is reduced to carbohydrates and water is
oxidized into oxygen. Plants of photosynthesis in green plants are simple carbohydrate
(sugar) and oxygen. Part of sugar is converted to the more complex carbohydrates like starch,
cellulose etc.

Chlorophyll:
 It is a green colored organic substance and is necessary for photosynthesis. There are
several kinds of chlorophyll but two types are the most important:
I-Chlorophyll a- C55H72 O5 N4Mg: Blue green pigment.
II-Chlorophyll b- C55H70O6N4Mg: Yellow green pigment.
 These pigments are formed inside the chloroplast.
 Other important pigments of photosynthesis are carotenoids and phycobillins.

Chloroplast:
A chloroplast of a higher plant is biconvex organelle. It is about 5 μm across the widest
plant. It is bounded by a double membrane within which following structure can be seen with
the help of the electron microscope.
Thylakoids:
 These are membranous structures within the chloroplast.
 Each thylakoid consists of a pair of membranes close to each other with a narrow space
between them.
 The function of thylakoid membranes is to hold the chlorophyll molecules in a suitable
position for trapping the maximum amount of light.
Stroma:
 The thylakoids are embedded in a watery matrix, the stroma.
 This contains the enzymes responsible for the reduction of CO2 and numerous starch
granules, the end products of photosynthesis.

Contents of Chloroplast:
Chloroplast contains many chemical substances which are as follows:
I -DNA: It is in a substantial amount and is capable of programming synthesis of some
structure components.
II-Pigments: Following pigments are present in addition to chlorophyll:
 Xanthophyll: Yellow pigment.
 Carotene: Orange pigment.
 Phaeophytin: Grey pigment.
These pigments are involved in the absorption of light.
III-Enzymes: They are involved in catalyzing the chemical reaction of plant cells.

Photosystems:
According to current theory, chlorophyll molecules and associated electron acceptors
are located in units known as Photosystems. Each photosystems contains several hundreds
chlorophyll molecules.
There are two different types of photosystems
 Photo system I: The chlorophyll of PS-I utilizes the light of wavelength 700nm.
 Photo system II: It is also denoted as PS-II. Its chlorophyll utilizes the light of wavelength
680nm.
Each photosystem has a different chlorophyll composition.

Antenna Complex:
Each photo systems consist of light gathering antenna complex and a reaction
centre. The antenna complex consists of many molecules of chlorophyll a, chlorophyll b and
carotenoids.

ROLE OF LIGHT:
 The light comes in packets called Quanta. A single quantum of light is known as a
photon. The light travels in waves which have different length
 The light of longer wavelength has less energy and light of shorter wavelength
contains more energy. The human eye can only see the light of a certain wavelength.
 The visible light has a wavelength between 400nm (violet) and 700nm (red). The
light is composed of seven different colors violet, blue, blue-green, green, yellow,
orange and red.
 The molecules that absorb light are called pigments.
 chlorophyll a and b absorbs violet, blue and red region of light while yellow and
orange light is absorbed very slightly. Green light is reflected, so the plants are shown
green color.
 When light is captured in the antenna complex, it is rapidly transferred to the
chlorophyll molecules present in the photosynthetic reaction centre. The energy of
light photon results in the activation of an electron from ground state to an excited
state.
 This energy is used to start chemical reaction and all other steps of photosynthesis.

ROLE OF WATER:
 Photosynthesis is a Redox process. It requires H + and electron, to fulfill this
requirement H2O is split and electrons are transferred along with hydrogen ion(H+)
from H2O to CO2, reducing it to sugar.
H2O → ½O2 + 2 H+ + 2e−
  As water molecules splits, their oxygen atom combine to form molecules of oxygen
(O2). Thus we can say that water molecules provide H+ and e− necessary for the
reduction steps leading to the assimilation of CO2.

ROLE OF CO2:
 CO2 provides the carbon for the basic skeleton to a photosynthetic product.
 The opening and closing of stomata have an important effect on the regulation of
photosynthetic activity; particularly in C3 plants, which incorporate CO2 directly into
photo phosphorylated sugar intermediate.
 The rate of photosynthesis is increased by the increase of CO2 in the atmosphere.

MECHANISM OF PHOTOSYNTHESIS:
The process of photosynthesis is represented by the following equation:

Actually the process of photosynthesis is not as simple as it seems from the equation.
Many steps with a different enzyme at each step are involved in this process.
The process of photosynthesis occurs in two steps.
1- Light Reaction OR Light Dependent Reaction.
2- Dark Reaction OR Light Independent Reaction.

Light Reaction:
This reaction takes place in the presence of sunlight, so it is also called Photochemical
Reaction. In this reaction light is absorbed by chlorophyll a which becomes active and energy
rich compounds ATP (Adenosine Tri phosphate) are formed. It is an energy carrier molecule.
In this process another energy carrier molecule NADPH + H + is also produced.
The light reaction consists of two steps:
I- Electron transport.
II- Phosphorylation (Formation of ATP)

1- Electron Transport:
The light reaction of photosynthesis is started from the reaction centre PS-II (P680).
The steps of this process are as follows:

I- The chlorophyll b of pigment system – II (PS- II) absorbs sunlight and becomes activated, it
releases an electron. The electron becomes excited to a high energy level. The excited
electron produced within P680 is transferred to the primary electron acceptor Phaelophytin.

II- From primary electron acceptor (phaelophytin) it is transferred to the plastoquinone (pq),
which is associated with Fe ions.

III- From the plastoquinone the electron is passed to the cytochrome complex.

IV- The chlorophyll P680 gets electron from water by its splitting into two hydrogen ions and
oxygen. This process is called photolysis of water.

V- From the cytochrome complex the electrons is moved to plastocyanin (pc). Plastocyanine
is reduced, it is present in lumen. Plastocyanine is a Cu containing protein.
VI- The plastocyanine (Pc) moves along the membrane to PS-I, where the chlorophyll-a (P700)
accepts the electron. Thus chlorophyll also absorbs light energy.

VII- From the chlorophyll a, P680 the electron is transferred to Fe +3 in one of the Fe-S
proteins, called Ferrodoxin reducing substrate(FRS). It is the primary acceptor of
Photosystem- I.

VIII- from Ferrodoxin reducing substrate (FRS) the electron is transferred to the Ferrodoxin
(Fd). It is an ion containing protein.

IX-From Ferrodoxin the electron is transferred to NADP. The NADP is reduced to NADP+ H + at
the side of stroma of the membrane.

2-Photophosphorylation:
During the electron transport when the electron moves through the chain, its
energy is used by the thylakoid membrane to produce to ATP, it is called photo
phosphorylation. The electron does not come back to its original position, but it takes part in
the reduction of NADP to form NADPH + H+. In this way a cycle is now completed, so this
process is called Non-Cyclic Photo phosphorylation.
NADP + 2H NADP H+ H+
The ATP produced in the light reaction provides chemical energy for the synthesis of
glucose during dark reaction (Calvin cycle) of photosynthesis.

Cyclic Photo-Phosphorylation:
In this photosynthetic bacteria cyclic photo phorylation occurs. In this process the
chlorophyll a (P700) of pigment system. It absorbs energy for the sunlight. It becomes very
much activated and it looses an electron. This electron combines of many compounds and
then comes back to its original position. In this way a cycle is completed called Cyclic-
phosphorylation. During its journey it forms ATP compounds.
Finally in light dependent reaction (light reaction) these are three important steps:
I- Photolysis of water.
II- Reduction of NADP to NADPH + H+
III- Formation of ATP by photophorylation.
ATP and NADPH + H+ are used in light independent reaction (dark reaction) fig 11.5 pg
248

Dark Reaction (Calvin-Benson Cycle):

 The dark reaction does not require light and may take place both in light and dark
during light.
In dark reaction the hydrogen which is separated from water combines with carbon of
CO2 and forms simple carbohydrates by the help of energy rich compound ATP.
CO + NADPH2 ATP ↭ ADP [CH2 O] + H2O + NADP
(The path of carbon in photosynthesis)

In dark reaction chemical energy is used in the form of ATP and NADPH+ H +. Malvin
Calvin worked on the pathway of carbon to carbohydrates. Calvin got Nobel Prize on his
work. This cycle of chemical reaction is known as Calvin-Benson cycle (Reductive pentose
phosphate cycle). It is also called C3 Photosynthetic carbon reaction cycle.
The Calvin cycle actually consists of 13 main reactions which are catalyzed by 11
enzymes, but it can be divided into three distinct phases.
I- Carboxylation: In which CO2 combines with organic molecules, it is also called Carbon
fixation.
II- Reduction: In which organic molecules are reduced, phosphor glyceraldehyde (PGAL)
Compound is formed
III- Regeneration: In which reduced carbon is used to regenerate the carbon acceptor
molecules or for metabolism.
These steps can be explained in the following way:

 Carboxylation:
This is the first and key reaction of Calvin cycle where ribulose-1, 5 bisphosphate (RuBP) is
combined with atmospheric CO2 to produce a short lived, six carbon intermediate, which
breaks into two molecules of glycerate-3- phosphate(G3P).
RUBISCO
CO2 + 3 RuBP 6 G3P
This reaction is catalyzed by the enzyme ribulose-1, 5- bisphosphate
carboxylase/oxygenase (Rubisco).

 Reduction:
This phase of Calvin cycle comprises of series of freely reversible reaction. During this phase
G3P is reduced to glycerate-1, 3- biphosphate (G1,3P) and then triose phosphate [3 Phospho
glyceraldehyde(GA3P) and dihydronyacetone phosphate(DHAP)] at the cost of ATP and
NADPH produced during light reaction.

6G3P + 6ATP + 6NADPH 6GA3P + 6ADP + 6NADP + 6Pi

 Regeneration:
Many carbon rearrangements take place during this phase.
I-Three carbon compounds are rearranged to form 5-carbon units including the primary
acceptor molecule RuBP.

5GA3P + 3 ATP 3RuBP + 3ADP +2Pi

II- During this cycle 3 molecules of CO2 fix 3 molecule of RuBP (3 x C5) which produces 6
molecules of 3-carboncompounds (triose 6 x C3).

III- From these 6 molecules, five are required to regenerate RuBP (5 x C 3 → 3 x C5). Therefore,
only one molecule of 3 C is produced (generally called triose - phosphate), which can
 Re-enter the cycle. OR
 Be used for starch synthesis within the chloroplast OR
 Be exported via a phosphate translocator to cytosol for sucrose synthesis.

IV- For net synthesis of one G3P molecule, the Calvin cycle consumes a total of nine
molecules of ATP and 6 molecules of NADPH + H +. The light reaction regenerates the ATP and
NADPH+ H+.

V -The G3P spun off from the Calvin cycle becomes the starting material for metabolic
pathways that synthesize other organic compounds, including glucose and other
carbohydrates

VI- Not all the 3-C sugar is converted to 6-C sugar some of it enters a series of reaction, which
results in the regeneration of RuBP. This is very important because only by ensuring a supply
of RuBP can continue the fixation of CO2.
Alternative Mechanism Of Carbon Fixation In Hot And Arid Climate:
On a hot, dry hot, most plants close their stomata, a response that
conserves water. This response also reduces photosynthetic yield by limiting access to CO 2,
with stomata even partially enclosed, CO2 concentration begins to decrease in the air spaces
within the leaf, and concentration of O2 released from photosynthesis begins to increase.
These conditions within the leaf favor a seemingly wasteful process called Photorespiration.
In certain plants species alternate mode of carbon fixation that minimize
photorespiration even in hot, arid climates have evolved. The two most important of these
photosynthetic adaptations are:
I- C4 Photosynthesis: the plants which have this type of adaptation are known as C4 plants.
II- Crassulacean Acid Metabolism (CAM): These are known as CAM plants.

C4 Plants:
 The C4 plants are so named because they preface the Calvin cycle with an alternate mode
of carbon fixation that forms four- carbon compound (oxaloacetate) as its first product.
 The 4-C compounds release CO2 which is reassimilited into organic material by Rubisco
and the Calvin cycle.
 Among the C4 plants important to agriculture are sugar cane and corn, members of grass
family.

CAM Plants:
 A second photosynthetic adaptation to arid condition has evolved in succulent plants,
many cacti, pineapples and representatives of several other plant families.
 These plants open their stomata during the night and close them during the day, just
reverse of normal behavior.
 Closing stomata during the day helps desert plants conserve water, but it also prevents
CO2 from entering the leaves.
 During the night, when the stomata are open, these plants take up CO 2 and incorporate it
into a variety of organic acids. This mode of carbon fixation is called crassulacean acid
metabolism or CAM.
 The CAM plants store these organic acids unit moving in their vacuoles.

CELLULAR RESPIRATION:
“Respiration is the process of oxidation of food material in living organisms in which
energy is released”
Every living organism requires energy to carry out varied function. This energy comes out
from food molecules such as glucose. Some of the energy is stored by cell in the form of ATP
while rest is lost as heat. Thus a cell transfers energy from glucose to ATP through coupled
exergonic and endergonic reactions.
This Aerobic breakdown of food molecules with accompanying synthesis of ATP is called
Cellular respiration. CO2 and H2Oare produced as by- products.

C6H12O6 + 6 H2O + 6O2 6CO2 + 12 H2O + 673 k.cal/mol

Since water molecules appear on both the sides, the equation can be simplified as under
C6H12O6 + 6 O2 6CO2 + 6 H2O + Energy (ATP and heat)
On hydrolysis of ATP, under the action of enzyme ATPase, the terminal phosphate is
removed with the result that ADP and Pi are formed and certain amount of energy is
released.
ATP ADP + Pi + 7.3 Kcal/mole (enzyme used is ATPase)

Oxidative Phosphorylation:
The process of formation of high energy phosphate molecule (ATP) by redox reaction is
called oxidative phosphorylation.

MECHANISM:
During the above mentioned electron transport chain some of the electrons are utilized
for the production of ATP from ADP molecules as follows:
ADP + Pi ATP
In the process of respiration glucose loses hydrogen atom as it is converted to CO 2.
Simultaneously molecular oxygen gains hydrogen atoms and is being converted to H 2O. Each
hydrogen atom contains one electron and one proton. Thus transfer of hydrogen atom is the
transfer of electrons and protons.
The loss of electrons from one molecule is an oxidation and the gain by second molecule
is reduction. The overall reaction is known as redox reaction. In this process of respiration
glucose is oxidized with the loss of electrons and oxygen is reduced by the gain of electron.
During redox reaction, electrons give up energy; which is used in the synthesis of ATP from
ADP and Pi. This synthesis of ATP is called as Oxidative phosphorylation.

Types Of Respiration:
There are two types of respiration.
 Anaerobic respiration:
It takes place in the absence of atmospheric oxygen, as a result incomplete oxidation
of carbohydrates takes place. Due to incomplete oxidation the end products are alcohols and
organic acids and very small amount of energy is released. The process is also called
fermentation.
 Anaerobic respiration:
It takes place only in the presence of oxygen. As a result, complete oxidation of
carbohydrates takes place and energy is released and the end products are CO2 and H2O.

Fermentation:
Originally defined by W.Pasteure as respiration in absence of air, it is an alternative term
used for anaerobic respiration, the production of ethyl alcohol from glucose is called
Alcoholic fermentation and that of lactic acid as Lactic acid fermentation.

Economic Importance of Fermentation:

I- Fermentation through an inefficient method of harvesting biological energy, is an source of
many valuable products such as
Ethyl alcohol. Lactic acid, Propionic acid, Butanol.

II- Brewing and dairy industries rely on fermentation.

III- It is the source of ethyl alcohol in wines and beers. Wines are produced by fermenting
fruits particularly grapes. Beers are produced fermenting malted cereals such as barley.

IV- Yeast cells are used to make dough rise before it is baked to make bread.

V- Cheese, yogurt, and other dairy products are produced by microbial fermentation.

VI Lactic acid, which is slightly sour acid, imparts flavors to yogurt and cheese. Dairy products
containing lactic acid are more resistant to spoilage.

VII- The characteristic flavor to pickles is due to lactic acid and acetic acid.

VIII- Acetone and other industrially produced solvents also by-products of fermentation.

Mechanism of Cellular Respiration:

The oxidation of glucose to carbon dioxide and water in cells cannot occur
in a single reaction; there are no enzymes that can catalyze the direct attack by oxygen
reaction that can group into four phases.
i- Glycolysis: the conversion of glucose to two molecules of pyurvic acid, a 3-C compound,
with the formation of some ATP.
ii- Acetyl Coenzyme- A formation: from pyurvic acid and co- enzyme A, along with carbon
dioxide.
iii- Kreb’s cycle: which converts the acetyl group attached to co enzyme A to carbon dioxide
and removes electron and protons.
iv- Electron Transport Chain: which process the electrons and protons removed from the food
molecule during the preceding phase.

1- Glycolysis:
 The initial stage of respiration is called glycolysis in which O2 is not used. It is common
both in aerobic and anaerobic respiration. In this process carbohydrates are changed into 3-C
compound, the pyurvic acid. The reactions of glycolysis are as follows:

i- Glycolysis starts with glucose- the glucose is converted into glucose 6-phosphate by the
utilization of an ATP compound (an energy rich compound)

ii- Glucose 6-phosphate is changed into fructose 6 phosphate by the arrangement of carbon
atoms.

iii- Fructose 6-phosphate is converted into fructose 1-6, biphosphate by the use of an ATP
compound.

iv- Fructose 1-6 biphosphate is divided into 3-C compound, 3- phospho glyceraldehyde and
dihydroxyacetone phosphate.

v- 3-phospho-glyceraldehyde is changed into 1-3 biphosphoglycerate.

vi- 1-3 biphospho glycerate is converted into 3- phosphoglycerate. It reacts with ADP, which
forms ATP.

vii- 3- phosphoglycerate is changed into 2phosphoglycerate.

vii- 2 phosphoglycerate is changed into 2 phosphoenol pyurvate.

viii- In this process of ADP 2 phosphoenol pyurvate is converted into (pyurvic acid). ADP is
transferred into ATP.

Formation of ATP during glycolysis is called substrate level phosphorylation because

phosphat5e group is directly transferred to ADP from another molecule.
Net input and output of glycolysis are as follows:
Glucose 2 pyurvic acid + 2H2O

2ADP + 2Pi 2 ATP

2 NAD + 4 H 2NADH + 2H+
Breakdown of Pyurvic Acid:
The molecular remains of glycolysis are two molecules of pyurvic acid. There are
two major pathways by which it is further processes. Under anaerobic conditions it either
produces ethyl alcohol (Alcoholic fermentation) or Lactic acid (Lactic acid fermentation)
produces carbon dioxide and H2O via kreb’s cycle under Aerobic condition:

I- Alcohol Fermentation:
Each pyurvic acid molecule is converted into two steps:
I-In the first step pyurvic acid is decarboxylated under the action of enzyme to produce
acetaldehyde, a two- C molecule.
CH3.CO.COOH CH3CHO + CO2

Ii- In the second step NADH + H + reduces acetaldehyde to ethyl alcohol

CH3CHO + NADH + H+ CH3CH2OH + NAD+

Ethyl alcohol is toxic. Plants never use it. Neither it can be converted to carbohydrate nor
does it break up in presence of oxygen. Accumulation of ethyl alcohol is tolerable to certain
level. Plants must revert to aerobic respiration before the concentration exceeds that
tolerable limit, otherwise they will be poisoned.

II- Lactic Acid fermentation:

 When NADH + H+ transfers its hydrogen directly to pyurvic acid, it results in the formation
of Lactic acid

CH3.COCOOH + NADH + H+ CH3CHOH.COOH

 During extensive exercise such as fast running muscle cells of animals and humans beings
respire anaerobically.
 Due to an inadequate supply of oxygen, Pyruvic acid is converted into lactic acid from
muscle cells.
 When lactic acid can’t be removed as fast as it is produced, it accumulates in the cells and
causes fatigue
 This forces the person to quit or reduce exercise until normal oxygen levels are restored
to deprive it.

2-Formation of Acetyl CoA:

i- Aerobes utilize molecular oxygen to extract large amount of energy from two products of
glycolysis i.e, Pyurvic acid and NADH + H +.

ii- Pyurvic acid diffuses from cytoplasmic fluid(cytosol) into mitochondria, the sit of kreb’s
cycle.

iii- Before entering into kreb’s cycle it undergoes chemical changes. It looses one molecule of
CO2.

iv- The remaining 2-C fragment is oxidized to form acetyl group, the ionized form of acetic
acid and NAD+ is reduced to NADH + H+.

v- Finally co-enzyme (CoA), a sulfur containing compound derived from Vitamin B, is attached
to acetyl group. The product is Acetyl Coenzyme (acetyl CoA).

VI- The overall reaction is given below:

2 Pyurvic Acid + 2 Coenzyme -A +2 NAD+ 2Acetyl CoA + 2NADH +2H++ 2CO2

3- Kreb’s Cycle:
In this process, pyurvic acid is completely oxidized and release large amount of energy, it is
summed up by:
 2 CH3.COCOOH + 5O2 6CO2 + 4H2O + ENERGY

The kreb’s cycle is also known as TCA cycle (Tricarboxylic acid cycle) or Citric acid cycle.
The Citric acid cycle consists of following main steps:

i- Acetyl CoA combines with oxaloacetic acid and converts to citric acid.

ii- Citric acid on dehydration gives as Cis- Aconitic acid.

iii- Cis-Aconitic acid is converted to iso-citric acid.

iv- Iso-Citric acid is converted to a α-ketoglutaric acid. Iso-Citric acid undergoes

dehydrogenation and then oxidative decarboxylation to yield the 5-C compound α-
ketoglutaric acid.

v- α-ketoglutaric acid undergoes decarboxylation and is converted to succinyl CoA and CO2.

vi-Now the Succinyl CoA is tansformed to Succinic acid.

The bond joining coenzyme-A to succinic acid is an energy rich one and can be written as ~ S.
The energy of ~S bond of Acetyl CoA is used to bring about the addition of the acetyl group to
oxaloacetic acid to yield citric acid. The energy ~S bond of succinyl CoA can be converted to
an energy rich phosphate bond in the form of guanosine triphosphate (GTP), a compound
similar to ATP but contaning guanine rather than adenine. The GTP is converted into ATP.

vii- Succinic acid is dehydrogenated to form fumaric acid. The hydrogen is accepted by Flavine
adenine dinucleotide (FAD), rather than NAD+.

viii- Soon it converts to malic acid.

ix- Malic acid forms oxaloacetic acid.

Oxaloacetic acid on combination with Acetyl CoA repeats the cycle.

4-Electron Transport System:

 It is a chain of chemical reaction involving enzymes resulting in transfer to
hydrogen atoms to oxygen to form H2O and energy is given out.
Explanation:
Respiration is a chemical process in which hydrogen atoms, in pairs, are removed
from oxidizing substrate at various levels during glycolysis and subsequent degradation of
pyurvic acid via kreb’s cycle. A pair of hydrogen atom dissociates into a pair of proton.
2H → 2H+ + 2eˉ
 In respiration these are six steps at which hydrogen atom in pairs are released (one is
glycolysis, 5 in Kreb’s cycle).
 The electron thus released at this stage are accepted by NAD and FAD from where they
are passed along a chain of electron carries such as cytochrome b, cytochrome c, and
cytochrome a.
 While passing from one carrier to another there cytochromes are alternately reduced
(receive electrons) and oxidized (give up electron), and energy is released which is used in
formation of ATP from ADP and inorganic phosphate. This formation of ATP is called
oxidative phosphorylation and it takes place in mitochondria.
 Complete oxidation of glucose molecule (Hexose sugar) results in net gain of 38 ATP
molecules, which are released in cytoplasm available fro different metabolic reaction.

Energy Flow through the Ecosystem:

In an ecosystem organisms are linked together in energy and nutrient relationship.
 The energy can be defined as the capacity to do work.
 The team work can be used to any energy consuming process such as living cells maintain
electrical gradient across membrane and the active transport process which requires
expenditure of energy.
 However the ecological studies relating food requirement and energy relationship among
living components of an ecosystem are referred as bioenergetics.
 Energy is found in four main forms
a) Radiant energy.
b) Heat energy.
c) Chemical energy.
d) Mechanical energy.
 Energy flow takes place from the sun to the different components of an ecosystem.

Sun as a Source of Energy:

The ultimate source of energy in an ecosystem is sunlight.
i. Sunlight travels as electromagnetic waves and about 40% is reflected back from
clouds and other 15% is absorbed by some layer and converted to heat energy by
atmosphere.
ii. Remaining 45% reaches to earth of which a small fragment i-e, 2-3% is absorbed by
given plants while rest is reflected and dispersed.

Unidirectional flow energy:

i. The plants convert solar energy into chemical energy present in the bonds of chemical
substance (mainly ATP molecules).
ii. Different forms of energy are interchangeable and they follow the set rules of
thermodynamics.
 According to first law of thermodynamics, energy can be transformed from one form
to another but can neither be created nor be destroyed.
  Second law of thermodynamics states the no conversion can be 100% accurate and
some energy must escape as heat.

Trophic levels:
In a food chain a set of organisms is used by other set of organisms, thus eating and
being eaten, and each stage of particular set of organisms is referred as trophic level.
Explanation:
In an ecosystem heterotrophs depend upon autotrophic organisms for their food. The
autotrophic organisms produce organic food substances which are used by heterotrophic. In
an ecosystem following trophic levels exists.
First trophic level: It consists of autotrophic plants, which take energy from sun and convert it
into chemical energy in the form of ATP molecules. The plants are also referred as producers
. The producers are mainly photosynthesis organisms.
Second trophic Level: It consists of herbivorous; they feed on producers hence they are
known as primary consumers.
Third trophic level: It consists of secondary consumers. They depend for the food source on
primary consumers or herbivorous and hence they are known as carnivorous.
Fourth trophic level: Similarly the secondary consumers are eaten by tertiary consumers,
which are also carnivorous; hence they form fourth trophic level.
Fifth trophic level: The primary, secondary & tertiary consumers after their death are eaten
by decomposers, which are saprotrophs (bacteria or fungi) in this way they form fourth or
fifth trophic level.

Pyramid of energy:
The diagrammatic representation of various tropic levels of an ecosystem is referred to
as food pyramids or the pyramids of energy.
Explanation:
The quantitative studies of an ecosystem are carried out by two ways: i.e,
 By studying the food chain (or food web) and
 By ecological pyramids.
There are different ways to represent pyramids; these are discussed below.
i. Pyramid of numbers: the ecological pyramid is the pyramid of numbers. It is
diagrammatic representation of trophic levels i-e, producers, herbivores and carnivores.
ii. Pyramids of biomass: the second way is the use of pyramid of biomass; instead of
numbers at each level it involves total mass of the living organisms present at each
trophic level.
iii. Pyramids of energy: the third way of study is pyramid of energy.
 The relationship between different trophic levels is shown by means of pyramid energy.
 It provides best picture of ecosystem.
 It depends on rate at which food is being produced; however the pyramids of number
and biomass provide the picture of existing situation or standing situation.
 The base of pyramid is represented by primary producers showing the amount of energy
they trap during photosynthesis and convert it into chemical energy. Hence, the energy
flow from one trophic level to another is calculated & represented diagrammatically in
pyramid.
 Each bar of pyramid represents the amount of energy per unit area in given period of
time.
The efficiency of energy flow:
The efficiency of energy flow depends upon productivity of an ecosystem, which in
turn depends upon radiant energy. The productivity of an ecosystem may be primary and
secondary.
Primary productivity:
During photosynthesis green plants trap sunlight and convert it into food energy. The
energy stored in food material by primary producers is said to be primary productivity. It
depends on the rate & amount of energy available to an ecosystem. Only a part of it is
absorbed by chlorophyll in production of organic molecules.
i. Gross primary productivity: the rate at which chemical energy is stored by plant is
called gross primary productivity (GPP).
ii. Net primary productivity: About 20% of GPP is used by plants themselves in
respiration and other functions, whereas the remaining is stored and is called Net
primary productivity (NPP).

Secondary productivity:
The herbivores feed upon producers and thus the energy is transformed to second
trophic level i-e, primary consumers. The productivity of hetrotrophic consumers of various
levels is called secondary productivity.
The average efficiency of energy transfer from plants to herbivores is about 10% and from
animal to animal is about 20%.

Advantage Of Short Food Chain:

There is a great advantage of short food chain because there is a loss of less energy
in short food chain. In a large food chain, such as food web in which many food chains are
linked together there is a great loss of energy in the form of heat.
EXAMPLE: Man uses both plants and animals as food. When he eats plants, he is herbivores
i.e, primary consumer, when he eats animals, he is secondary consumer and when he eats
fishes, and he becomes tertiary consumer. In short chain the loss of energy is less.

CHAPTER 12: NUTRITION

NUTRITION:
Nutrition is the process by which the organisms obtain energy to maintain the function of
life.

Types of Nutrition:
There are two types of nutrition:

 Autotrophic nutrition:
When the living organism can manufacture their own food material, it is called as Autotrophic
nutrition and the living organisms are known as Autotrophs.
 Heterotrophic nutrition:
When the living organism cannot manufacture their own food material and they depend
upon other organism for their food, it is called as heterotrophic nutrition and the living
organism are known as heterotrophs.

Mineral Nutrition in Plants:

In plants, the sources of inorganic requirement are minerals nutrients and soil.
These elements are known as mineral nutrients and the nutrition is called as Mineral
Nutrition. Nitrogen is also included in mineral nutrients because it is normally obtained by the
plant from soil whereas it is not a mineral element.
The amount and number of elements present in plant may also differ from plant to
plant, place to place and medium to medium in which the plant grows. Some important
mineral nutrients which are required in large quantities (macronutrients) are as follows:

1-NITROGEN (N):

It is found in the soil in the form of nitrates or ammonium salts. It is an essential constituent
of protein, nucleic acid and chlorophyll.

Deficiency Symptoms:

 Chlorosis: Due to the loss of chlorophyll, yellowing of leaves develops, called chlorosis.
 Process of cell division and cell enlargement are inhibited.
 Rate of respiration is affected.
 In certain plants, veins, turns purple or red due to the development of Anthocyanin
pigment e.g.: tomato and apple leaves.
 Plant growth stunted and lateral buds remain dormant, as a result cereals do not show
characteristic tillering.
 Seed dormancy is prolonged and leaf fall (senescence) starts

2-PHOSPHORUS (P):
Plants absorb phosphorus in the form of soluble phosphates such as H3PO4 and
HPO4. It is sufficient amount in the growing and storage organs such as fruits and seeds. It
promotes healthy root growth and fruit ripening by helping translocation of carbohydrates.
It is essential element involved in the formation of cell membrane and phospho-
lipids, nucleic acid, co-enzyme (NAD and NADP) and organic molecules such as ATP and other
phosphorylated products. It plays an important role in the energy transfer reaction in
oxidation-reduction process.
In case of phosphorus few deficiency symptoms resembles that of nitrogen like pre-mature
leaf fall and development of purple red anthocyanin pigment. Deficiency of phosphorus also
shows some other symptoms.

Deficiency Symptoms;
Cambium activity is affected.
Tillering of crop plant is reduced.
Dormancy is prolonged.
Growth is retarded and dead necrotic patches appear in leaves petioles and fruits.
Variable colors develop eg; plate green in Pisum.
Accumulation of carbohydrates occur
Thickening of tracheal cells are reduced.
POTASSIUM (K):
Potassium is widely distributed in soil minerals. It is strongly fixed in soil, therefore found in
less available form. Exchangeable potassium appears to be readily available to the plants.
The best known function of potassium is its role in stomata l opening and closing. It is found
in in highest concentration in meristematic regions of plants. It is an essential element of
enzymes involved in the synthesis of peptide bonds and carbohydrate metabolism.

Deficiency Symptoms;
The color of leaf may turn into dull or bluish green.
An irregular chlorosis occur first, which is followed by the development of necrotic areas of
the tip and margin of leaves.
Plant is stunted in growth with the pronounced shortening of internodes and reduced
production of grains.
Lamina of broad leaved plants and curl backward towards the under surface or roll forward
towards the upper surface parallel with midrib.

MAGNESIUM (Mg);
Magnesium is required by the plant for the formation of chlorophyll. Without chlorophyll
photosynthesis cannot occur. It is also activator of certain enzymes. It acts phosphorus
carriers in plants. It takes part in seed formation having high quality oil. It is also required in
synthesis of fats and metabolism of carbohydrates and phosphorus.

Deficiency Symptoms:
Deficiency symptoms develops first on the older leaves and then proceed systematically
towards younger leaves.
Chlorosis occurs.
Severely affected leaves may wither and shed. Defoliation may be quite severe.
Leaves sometimes develop necrotic spots.

HETEROTROPHIC AND SPECIAL MODE OF NUTRITION IN PLANTS:

Plants which are not able to manufacture their own organic compounds entirely or
partially for these organic molecular requirements on outside sources and are called
heterotrophic plants.

Parasites: Those plants which depend on living plants and animals for their nutritional
requirements are called parasites.

Obligate/total parasites: Parasites which depend for their entirely on other living organisms.

Facultative/partial parasites: Those plants which partially depends on other organisms.

Saprophytes: The plants which depend on dead or rotten organic remains of plants and
animals are called saprophytes.

Total saprophytes: The plants which entirely depend on dead organic matter are known as
total saprophytes.
Partial saprophytes: Those which depend on these requirements partially on dead organic
matter are called partial saprophytes.

 PARASITIC PLANTS:
The parasitic plants produce special root like structures called haustoria. These
haustoria penetrate into host plant body and absorb food material.

PARASITIC ANGIOSPERMS:
The parasitic angiosperm plants are as follows;

partial stem parasites

total stem parasite
partial root parasites
total root parasite

1: PARTIAL STEM PARASITE:

These plants grow upon other host plants. They can manufacture some of their food due to
presence of chlorophyll and they partially depends upon other host plants. They absorbs
nutrients and water from host plants by the help of haustoria.

Examples

(a) It has thick green leaves, woody stem and haustoria. It grows up on mango, Bauhinia
plants, rosaceous trees and many shrubs.

(b)Viscum produce haustorial branches for interna sucking system.

(c)Cassytha filiformis found in tropics, a leafless wiry stem, send the haustoria that penetrates
in the system to develop connection with vascular tissues of host plants.

2: TOTAL STEM PARASITE:

These plants completely depend on host plants for their food. They produce haustoria into
the body of host plants and absorbs food material ultimately the host may die.

Examples
Cascuta plant (amer -bail)

3: PARTIAL ROOT PARASITE:

These plants get their food partially from the roots of other plants.

Examples;
Sandal wood tree. Its seedling does not grow independently. Its roots absorbs nourishment
from the root of other plants.

4: TOTAL ROOT PARASITE:

These plants obtain their food completely from the roots of neighboring plants. These plants
usually attack the plants of family cruciferae and solanacea.

Examples:
Orabanche, striga-cistanche parasites on the roots of calatropisplant.Striga is a parasite on
the roots of sugarcane etc.

5: SAPROPHYTES:
Plants which break up dead organic matter into simpler forms and use them for their growth
and development are saprophytes. These are examples found among flowering plants like
neotha and monotropa.in these cases the roots of the plants form a mycorrhizal association
with fungal mycelium to help in the absorption process.

 CARNIVOROUS (INSECTIVOROUS) PLANTS;

Some plants use insects so they are called carnivorous or insectivorous plants. These plants
show certain modifications to capture insects.
These plants contain chlorophyll and manufacture own food, but cannot prepare nitrogenous
compounds and proteins, so to get these compounds they use insects.
These plants usually grow in those regions where nitrogen is deficient, so they depend upon
insects for nitrogen and proteins.

Some common examples are;

1. PITCHER PLANT:

In this plants leaves are modified into flask shaped structures called leaf pitches. These plants
are used to capture insects. The pitcher also has a lid to close it's mouth. When insects come
on its mouth they are slipped into the pitcher. From the inner surface of pitcher digestive
enzymes are secreted, which help in the digestion of insects.
Examples: Nepenthes, Sarracenia, Cephalotus, Heliamphora, Darlingtonia.

2. DROSERA INTERMEDIA (SUNDEW):

A plant with loose and about half a dozen prostrate radiating leaves. The tiny leaves bear
hears like tentacles with glands at its tip. The insects attracted by plants odor, are enlarged.

3. DIONAEA MUSCIPULA (VENUS FLY TRAP):

It is most well-known of all carnivorous plants. Charles Darwin called it the most wonderful
plant in the world.
It has rosette of prostrate radiating leaves with the inflorescence in the center. The
function of petiole and lamina is constricted up to mid-rib, the petiole is winged and lamina
has two halves, with midrib in center. Each half has12 to 20 teeth. The teeth of one half is
interlocked with other half. In the center of the dorsal surface of lamina are numerous
secretory glands, three hair projecting outwards which are sensitive to touch.

4. ALDROVANDA(WATER FLY TRAP):

A rootles aquatic plant with floating stem.it has rosette of modified leaves which has two
lobed mobile lamina having teeth at the margin and sensitive jointed hairs and stalked gland
on the surface.

5. UTRICULARIA OR BLADDER WORT:

Rootles plant have much branched slender stem. Leaves are also much divided, some of
the leaflets are also developed into bladder like traps of about1/16 to 1/8 inches in diameter.
 HOLOZOIC NUTRITION

When complex food substance are taken in, these are converted into simple diffusible forms
by enzymes, it is absorbed by body and then it takes part to provide energy in the body, this
process is called holozoic nutrition.
It consists of following steps;

Ingestion:
When complex food substance is taken inside the body by the help of certain organs, it is
called ingestion.
Digestion:
When complex food substance are converted into simple diffusible form by the action of
certain enzymes, it is digestion.

Absorption:
When the digested, diffusible food substance are diffused into the body or cells across the
membrane of digestive part, it is called absorption.

Assimilation:
When the products of digestion are used to produce energy in the body, it is called
assimilation.

Egestion:
When undigested food substances is expelled out of the body, it is called egestion.

a) NUTRITION IN AMOEBA

Amoeba is a macrophages feeder, it feeds upon small aquatic organisms like bacteria,
flagellate and minute food particles.

PROCESS OF NUTRITION;

Ingestion:
When a hungry amoeba approaches to food particles, it produces out its [pseudopodia in the
form of food cup, which engulf the food particle by turning into food vacuole. The food also
contain some water. This completes ingestion.

Digestion:
This is the next step which is facilitated by lysosomes.
A few lysosomes surrounds the food vacuole and get fused with the membrane, to
discharge their enzyme contents (protease, amylase and lipase) into it. Hence the digestion is
intracellular.
At this stage the vacuole becomes food vacuole.
It decreases in size as water is withdrawn and its content first become acidic (pH; 5.6) and
then alkaline (pH' 7.3)
When the digestion is completed, the digestive vacuole membrane is drawn into numerous
fine canals.
The soluble food particles are passed into the canals and finally into the surrounding
cytoplasm by micro pinocytosis.

Absorption and Assimilation:

The digested food, water and minerals are absorbed into the cytoplasm and circulate in it,
through cyclosis where the food is assimilated into new protoplasm or is oxidized to liberate
energy
Egestion:
The undigested food is egested by exocytosis at the rear end.

b) NUTRITION IN HYDRA
Hydra is one of the simplest heterotrophs to engage in extracellular digestion within its body
cavity

Structure;
The body of hydra is hollow.
Its body wall consists of only two layers of cells, which are held together by a non -cellular
middle layer called mesoglea.
The hydra possess a definite mouth, surrounded by tentacles.
The tentacles have nematocysts, which can penetrate and paralyze the prey

PROCESS OF NUTRITION:

Ingestion:
When the prey organism brush against the projecting cnidocils of nematocyst located on the
tentacles, their contents are discharged and prey is paralyzed.
The tentacles then bent over the mouth along with other tentacles.
The mouth opens widely, enabling the prey to the body resulting in ingestion.

Digestion:
The mouth opens into body cavity called (coelenteron), bounded by the endoderm having
glandular and flagellated musculoepithelial cell.
The former secrete proteolytic enzymes, which initiate extra cellular digestion.
The flagellated cells and the contractile of body wall help in circulation of food and enzymes
and result in mechanical digestion.
Hydra can digest proteins, fats and some carbohydrates but not starch.
Extracellular digestion is completed in about 4 hours.
The semi digested food particles are engulfed by the phagocytic action of the flagellated
cells where they are completely digested.
Thus the digestion in hydra is extra cellular as well as intra cellular.

Absorption:
Absorption of the digested nutrients is simple as the cells lining the body cavity are quite
close so that the nutrients easily diffuse throughout the body.
The soluble food particles are diffused through mesoglea into the ectodermal cells.

Egestion:
The undigested food is egested through the mouth.
c) NUTRITION IN PLANARIA

Planaria is one of the Platyhelminthes.

It is a free living worm.
It is carnivorous and feeds upon small worms, crustaceans, snails and dead animal debris.

Digestive Organ;
1. Mouth of planaria is located behind the middle of the body and serve both of ingestion and
digestion
2. Mouth leads into pharynx.
3. Pharynx leads into intestine, which divides into three branches.
4. One branch extends forwards in the middle up to head.
5. Other two branches extend backward to the posterior end.one on either side of
pharyngeal cavity. All branches of intestine give off numerous branching diverticula, all
ending there being no anus.

PROCESS OF NUTRITION:

Ingestion:
In feeding the animal moves towards food.
The prey gets entangled in the slimy secretion produced by the mucous glands.
Soon the pharynx is averted out through the mouth situated on the mid ventral surface and
seizes the prey.
It is withdrawn quickly into the pharyngeal sheath along with the prey.

Digestion:
Food is often entangled in the slimy secretion of mucous glands and then digestive juices
are poured onto the food.
Food is broken up by pumping action of pharynx and is swallowed.
Extra cellular digestion starts by pumping action of pharynx and enzymes.
The pharynx opens into the intestine which consists of three branches, an anterior and two
lateral.
All these branches give off numerous branching diverticula which ramify throughout the
body penetrating into the tissues, ending blindly.
Anus is absent, and digestive system is sac-like.
Digestion is both intra-cellular and extra-cellular. Partially digested food particles are taken
into the cells lining the diverticula, where they are completely digested.

Absorption:
The digested food is then diffused into the mesenchyme cells which help in distribution.

Egestion:
Undigested food is expelled out of the body.

d) NUTRITION IN COCK ROACH:

Introduction:
Cockroach belongs to phylum arthropoda and class insecta. They are omnivorous in nature
i.e., takes any kind of organic matter. They uses its antennae in the search of food.

DIGESTIVE SYSTEM:
The digestive system of cockroach consists of tube like alimentary canal, which extends from
mouth to anus.it can be divided into following three parts;
a) Foregut or stomodaeum
b) Midgut or mesenteron
c) Hindgut or proctodaeum

FOREGUT:
It is upper region of alimentary canal.it consists of following parts;
Mouth and buccal cavity:
The mouth opens into pre-oral cavity, which is bounded by mouth parts, upper lip (labrum),
lower lip (labium), jaws mandibles and maxillae and hypopharynx tongue.
The maxillae pick up and brings food to the mandibles for mastication of food where it is
mixed with saliva, secreted by salivary glands. The saliva contains amylase, which digests
carbohydrates.
Pharynx:
Mouth opens into pharynx. It is tube like present up to end of head.
Oesophagus:
Pharynx passes food into narrow and thin walled tube called oesophagus.
Crop:
Crop is pear shaped sac like large part, present in thorax.it stores food material.
Gizzard:
It is small rounded thick walled structure. Its internal lining is raised into six teeth like
structure which grind and strain the food.

MIDGUT:
It is narrow tubular portion having eight club shaped structure called hepati ceaca. These
secrete digestive enzyme and absorption of food also takes place in midgut.

HINDGUT:
It is lower region consists of three parts;
a) Ileum:
It is upper part of hind gut. It joins mesenteron with colon from its outer region thread like
structures are developed called malphigian tubules, which helps in excretion.
b) Colon:
It is long coiled part, open into rectum.
c) Rectum:
Rectum is long coiled part and last part of digestive system it opens into the outside by anus
and then undigested food material is expelled out of the body.

HUMAN DENTITION
In mouth mechanical digestion takes place through teeth. There are different types of teeth
in man incisors, canines, pre molars and molars. Incisors and canines are the anterior teeth
while pre molar and molars are the posterior ones. They change the food into small particles.
Man has two sets of teeth, it is called diphycodont.one set is of milk teeth deciduous,
these are replaced by another set, permanent teeth. They are of different shapes and sizes, it
is called heterodont, these teeth are embedded in gums, and it is called thecodont. The man
has 8 incisors, 4canines, 8pre molars and 12 molars. Human dental formula is:
(i 2/2 ,c 1/1 ,pm 2/2, m 3/3) x 2 = 32.

PLAQUE AND DENTAL DISEASES:

When salivary material and bacteria are mixed together, it is called plaque. Many disorders
and abnormalities can occur by plaque.

PERIODENTAL DISEASES;
When plaque is accumulated, bacteria cause inflammation of gums.by this continuous
process inflammation spreads to the roots of teeth and destroy their periodontal layer, due
to which teeth becomes loose and fall off, it is called periodontal disease.
CALCULUS:
When plaque combines with certain chemicals in saliva, it becomes harden and calcified.it
is deposited on teeth and cannot be removed easily, it is calculus.
DENTAL CARIES:
When enamel part of teeth is destroyed and dentine and pulp are attacked by bacteria,
when they convert sugar into acid, it causes tooth ache and loss of teeth, it is called dental
caries.
There are many factors of dental caries;
a) Sugary food stuff are used and teeth are not cleaned properly
b) Saliva composition may be disturbed and changed.
c) Lack of oral hygiene
d) Low level of fluoride in drinking water.

DIGESTION IN MAN

‘The process by which food is broken down into simple chemical compounds that can be
absorbed and used as nutrients or eliminated by the body’.

Man belongs to class Mammalia. The shows the most advanced heterotrophic nutrition. In
man extra-cellular digestion is present. The digestion takes place in tube like alimentary
canal, also called gastro intestinal tract.
PARTS OF ALIMENTARY CANAL:
The alimentary canal of man consists of following parts.
1. Mouth and buccal cavity
2. Pharynx
3. Esophagus
4. Stomach
5. Small intestine
a) Duodenum
b) Jejunum
c) Ileum
6. Large intestine:
a) Caecum
b) Colon
c) Rectum

GLANDS:
In the body of man three types of
glands are present, which secretes
digestive enzymes, these are;
(i) Salivary glands
(ii) Liver
(iii) Pancreas

MOUTH AND ORAL CAVITY:

It is anterior opening of the gut,
which is bounded by fleshy lips.
The lips not only close the mouth
but also help in digestion.
The mouth opens into oral cavity
which is a wide cavity supported by
the walls of skull.
The cheeks forming its side wall,
the tongue it's floor and palate its
roof.
The jaws forms the boundary of
the mouth.
The upper jaw is fixed but lower
jaw is moveably attached.
Both the jaws bear teeth which are
used to masticate food into small
pieces, resulting in mechanical
digestion which increases the surface area of food for the action of enzymes.

TONGUE:
The tongue is a muscular fleshy structure lying on the floor of oral cavity having taste bud and
tongue papillae.it is attached posteriorly and free anteriorly.it function as spoon and mixes
the masticated food with saliva and afterwards helps in swallowing.
SALIVARY GLANDS AND SALIVA:
The oral cavity has three pairs of salivary glands which produce about1.5 liters of saliva each
day.
a) Parotid gland; lie at base of pinnae
b) Sublingual gland; lie at base of tongue
c) Sub mandibular glands; lie at the base of lower jaw

-Composition of Saliva:
The saliva is a watery secretion containing 95% H2O, some mucous, amylase, and lysozyme
enzyme.

-Functions of Saliva;
The mucous moistens the food for comfortable swallowing.
The salivary amylase begins the digestion of starch. First to dextrin, and then to disaccharide
maltose.
Lysozyme destroy the oral cavity pathogenic bacteria.
Ultimately the semi-solid, partially digested food particles stick together by mucous and
molded into rounded mass bolus by the tongue which then pushes food into pharynx.

PHARYNX AND SWALLOWING:

Pharynx is the posterior narrow part of buccal cavity which contain openings of following
structures;
 Esophagus
 Glottis
 Internal nostrils
 Eustachian tube

-Process of Swallowing:
The swallowing initially is a voluntary action but afterwards it continues as involuntary
action.
The soft palate helps in swallowing during which the elastic cartilaginous flap epiglottis is
pushed over the glottis by the upward movement of larynx.so that no food goes in the
trachea.
However when accidently something other than gasses comes between epiglottis and
glottis, a powerful coughing reflex expels it out.
The swallowed food in the form of bolus moves into esophagus.

OESOPHAGUS:
This is narrow muscular tube containing mucous glands about 25cm running through the
thoracic cavity. It conveys the food and fluids into pharynx by peristalsis movement.

-Peristalsis:
The basic propulsive movement of GIT is known as peristalsis.
These are alternate rhythmic contraction and relaxation of the gut wall.
The usual stimulus for peristalsis is distention of esophagus.
To swallow H20 peristaltic movements are required, although it can flow down easily.

-Anti-Peristalsis:
In the early stages of gastro intestinal irritation, antiperistalsis begins to occur often, minutes
before vomiting appears .when the abdominal muscle contract, the stomach is squeezed.
Finally the gastro esophagus sphincter relaxes allowing the expulsion of gastric contents
upwards through the esophagus in the form of vomiting.

STOMACH:
The stomach performs several important functions, these are mechanical and chemical.

 Mechanical Digestion:
Stomach performs two mechanical functions;
1. Storage of food and
2. Physical breakdown of food by action of its muscular contractions the food is reduced to a
pulp called chyme.

 Chemical Digestion:
Chemical digestion takes place by the action of enzymes. The stomach has three regions; its
upper region is called cardiac end, this end contains a valve called cardiac sphincter. The
middle region is called fundus. It is the main part containing gastric glands. The glands have
three types of cells:
a) Mucous secreting cells.
b) Zymogen cells which secrete pepsinogen enzyme
c) Oxyntic cell which secrete HCL.
The lower part of stomach is called pyloric end. It opens into duodenum having a valve called
pyloric sphincter. When food comes into stomach the gastric glands secrete gastric juices
which is mixed with food.

GASTRIC JUICE:
It contains following compounds:
1: Mucous: protects inner lining of stomach by the action of enzymes
2: Water: Moisten and softens the food
3: HCL: Stops the action of saliva and kills the bacteria, also provides acidic medium.

 ENZYMES:
1. Pepsin: by the action of HCL pepsinogen enzyme is converted into pepsin which converts
proteins into peptones and protease.
2. Renin: it changes milk into curd in young ones. In adults this process takes place by HCL.
3. Gastrin: In stomach a hormone is produced called gastrin. It activates gastric glands to
produce gastric juice.

 SMALL INTESTINE:
Stomach leads into small intestine. It is about 6 times long 2.5cm wide. It consist of 3 parts
1. Duodenum 2. Jejunum 3. Ileum.

1. Digestion in Duodenum:
Stomach directly opens into duodenum. It is about 30 cm long and runs parallel to the
stomach. It receives a common bile duct and pancreatic duct through a common aperture.
When food comes into the duodenum, it mixes with the bile, which is secreted by the
liver. It contains water, bile salts and bile pigment.

 BILE:
1. It neutralizes acid in the food and makes it alkaline.
 2. It acts upon the fat and converts them into milky suspension i.e. emulsification takes place.
3. These are two bile pigments, red pigments is bilirubin and green is biliverdin. These are
produced by the breakdown of hemoglobin of ruptured RBCs in the liver. The bile pigments
are excretory products.

 PANCREATIC JUICE:
It is secretion of pancreas. It is produced by the activity of a hormone called secretin,
produced by the duodenum. Secretion of enzyme is also produced due to HCl which comes
from stomach along with food.

Pancreatic juice contains following enzymes:

i. Trypsin (Protease):
It is an active enzyme, but it is converted into active enzymes from inactive enzyme
Pepsinogen by the activity of enterokinase enzyme.
Trypsin acts upon proteins and converts them into polypeptide.
ii. Chymotrypsin:
It converts milk protein casein into amino acids.
iii. Amylase:
It converts starch into maltose.
iv. Lipase:
It converts fats into fatty acids and glycerol.

2. DIGESTION IN JEJUNIUM:
 Duodenum opens into jejunum.
 It is about 2.4 meters long.
 It secretes following enzymes:

i.Peptidase (Erepsin):
It acts on tripeptides and dipeptides and converts them amino acid. These are diffusible
substances.

ii.Maltase:
It converts maltose into glucose.

iii.Sucrase:
It converts sucrase into glucose and fructose.

iv.Lactase:
It converts milk sugar into glucose and galactose. In this way starch is changed into simple
sugar.

3. ABSORPTION OF FOOD IN ILEUM:

 Absorption of food takes place in ileum. It is about 3.6 meters long. It receives much
diluted food called chyle.
 The inner surface of ileum has numerous finger like projection, called villi. The villi
contains smooth muscles. These are supplied by blood capillaries lacteal. Lacteal are lymph
vessel.
 As the result of digestion the carbohydrates changed into simply into sugars and
proteins are converted into amino acids. These are absorbed by mucous membrane of villi.
 The absorption food is by diffusion or active transport.
 The simply sugars and amino acids are carried to the liver by hepatic portal vein-fatty
acids and glycerol are absorbed by the epithelial cells of villi. In these cells they are changed
into simply fats, called triglycerides. The simply fats are diffused into lymph vessels called
Lacteals.

LARGE INTESTINE;
The large intestine consist of three parts:
1. Caecum 2.Colon 3.Rectum

Caecum: It is the part which lies below the T like junction with the small intestine is called
caecum. It contains bacteria which take part in the digestion of cellulose. The caecum has a
small finger like projection, called Vermiform appendix. Sometimes some food substances are
diffused into the appendix and cause disturbances and infection. It is called Appendicitis. Due
to extreme pain the appendix is removed from the body.

Colon: It consist of three portions, an ascending a transverse and a descending portion. It

reabsorbs H2O and salts from the undigested food and returns them to the circulatory
system. They are again used by the body. If this reabsorption of water and salts does not
occur diarrhea causes in which excessive loss of water occurs.

Rectum: It is the last part of large intestine. It opens to the outside by anus. When the
undigested food enters the colon, it reabsorbs water and salt from it. The remaining
undigested food comes into the rectum and the discharge out of the body through anus.

 ANUS AND EGESTION:

The external opening of the anal canal is known as anus. It is used in egestion. The bulk of
faeces consists of dead bacteria, cellulose and other plants fibers dead mucosal cells, mucus,
cholesterol, bile pigment, derivatives and water, pass out through anus. Two sphincters
surround the anus, an internal one of smooth muscle under the control of autonomic
nervous system and as outer one of striated muscle controlled by voluntary nervous system.

LIVER:

 Location and Structure:

It is the largest gland of the human body and take part in digestion of food. It is reddish
brown and present below the diaphragm on the right side. It consist of two lobes and the left
lobe has also two lobes.

 Secretion:
Liver cells produce bile juice which is collected by two hepatic ducts and store in a pear
shaped structure called gall bladder. It combines with the cystic duct of gall bladder forming
common bile duct which joins the pancreatic duct and opens into duodenum.

 Function Of Liver:
The liver is basically a metabolic factory, detoxification centre, and storage organ with one
major function i.e. to maintain appropriate quantity of nutrients in the body.
i. Storage Function:
A sizeable amount of glucose is usually deposited in the liver after every meal, here the
glucose is transformed into glycogen (animal starch), which can later be hydrolyzed for
energy. The sugar is thus stored (as glycogen) so it will be readily available to meet the body's
energy needs as they occur.

ii. Detoxification:
The liver can also plays an important role in preventing certain poisons from harming the
body. Minor quantities of poisonous substances such as DDT can be broken down to
harmless compounds in the liver.

iii. Metabolic Functions:

Liver performs very important role in the metabolism of proteins, carbohydrates and lipids.

iv. Synthetic Function:

Many useful bio-chemical molecules such as enzymes, vitamins, cytokines, etc, are
synthesized in liver.

PANCREAS:
Pancreas is also an important gland. It is present behind in stomach. It is an exocrine gland
because secrete pancreatic juice, which contains important enzymes for digestion of food.
The pancreas also acts an endocrine gland as, it also secretes a hormone, called insulin. This
hormone converts sugar into glycogen. It also secretes another hormone, called glucagon. It
again converts glycogen into glucose for the production of energy.

DISORDERS OF GASTROINTESTINAL TRACT

In the digested cavity of human being many disorder and diseases can be developed.
These are as follows:

1. DIARRHOEA:
Diarrhea is defined as the passage of loose, semi-solid or liquid stool, which are passed at a
frequency greater than is usual for the patient.
Diarrhea is also commonly known as loose motion and it results from rapid movement of
faucal matter through the large intestine.

Causes:
Diarrhea may occur due to several causes, some of them are given below:

ENTERITIS: Caused by virus or by bacteria in the intestinal tract due to the infection mucosa
becomes irritated. The motility of intestinal wall increases many fold.

CHOLERA: It is another common cause of diarrhea, bringing about extreme quantities of bi-
carbonate ions come to be secreted into the intestinal tract along with the massive amount
of Na+ and H2O, and leading to death.

PSYCHOGENIC DIARRHEOA: It is caused by nervous tension.

INFLAMMATORY CONDITION OF LARGE INTESTINE: such as ulcerative colitis, etc. are some
common causes.

2. DYSENTERY:
Dysentery is an acute inflammation of the large intestine characterized by diarrhea with
blood and mucus in stool. It is caused by bacillary or amoebic infection.

3. CONSTIPATION:
Constipation is defined as a slow movement of faeces through the large intestine and is often
associated with large quantities of dry hard faces in the descending colon.
Causes:

Hard faeces accumulate because of long time available for fluid absorption.

Hard faeces accumulate because of long time available for absorption of fluid.
A frequent cause of constipation is irregular bowel habits that have developed through a life
time of inhabitation of normal defecation reflexes.
Some diseases also have a sequence of constipation.

4. PILES (Hemorrhoids):
Piles also known as hemorrhoids, are dilated veins occurring in relation to the anus. Such
hemorrhoids maybe external or internal to the anal opening.

EXTERNAL PILES are covered by skin.

INTERNAL PILES lie beneath the anal mucous membrane.

Causes:
The most common cause of pile is constipation.
The pressure exerted by the person to defecate stretches. The skin along with the veins
resulting in the dilations forming hemorrhoids.

Preventive Measures:
Piles can be avoided by
1. Regular habit of defecation
2. The use of fiber diet which in course in texture and makes it easier to pass out.

5. DYSPEPSIA:
Dyspepsia is commonly known as epigastric discomfort following meals.
This is characterized by heart burn, flatulence, by the anorexia, nausea and vomiting with or
without the abdominal pain.

Causes:
It may be due to peptic ulcer.
Taking fat rich meal in excessive amount.
It may be caused by disturbance in the motor function of the alimentary tract.
Some persons have persistent dyspepsia for which no cause can be found.

6. PEPTIC ULCER:
A peptic ulcer is a damaged area of mucosa caused by the digestive action of gastric juice, in
the first few centimeters of duodenum. Peptic ulcer frequently occur in the stomach or more
rarely in the lower end of esophagus where stomach juices frequently reflex.

Causes:
Excessive secretion of acid and pepsin by the gastric glands
The development of duodenal peptic ulcer is strongly hereditary.
In addition to hereditary factors psychogenic factors that causes stress and anxiety.

7. FOOD POISONING:
Food poisoning can be caused due to many causes like the infection by virus, bacteria and
protozoa.
It may be non-infective due to allergy.
It presents with vomiting, diarrhea or both usually within 48 hours of consumption of
contaminated food or drink.
SALMONELLA species is very common which causes food poisoning.

8. MAL-NUTRITION:
When an organism is deficient in or receives excessive amount of one or more nutrients over
a long period of time, it is said to have mal nutrition.
The deficiency is known as under nutrition, and excess is called over nutrition.
Under nutrition is the most common problem of under-developed countries.
obesity with heart ailments and reduced life expectancy are the symptoms of over nutrition/

9. OVER WEIGHT AND OBESITY:

Obesity may be defined as the condition in which there is excessive amount of body fats
It is the most common nutritional disorder.
Excessive fat accumulates because there is imbalance between energy intake and
expenditure.
it is most popular in middle age but can occur in any age
It can be a family tendency.
Over weight is associated with an increased rate of mortality.

10. ANOREXIA NERVOSA:

Anorexia nervosa is loss of appetite for food.
 It is psychological condition usually seen in girls and young women.
It is characterized by severe and prolonged inability or refusal to eat.
Sometimes accompanied by spontaneous or induced vomiting.

11. BULIMIA NERVOSA:

It is almost exclusively confined to women and the age of onset is slightly older than for
anorexia.
Symptoms:
a) Recurrent bouts of binge eating
b) Lack of self-control.
c) Over eating during binges.
The binges occur at least twice weekly.it involves rich food such as cakes, chocolates, and
dairy products.
It is exclusively abnormality found in adult women.
 ENDOPARASITES OF MAN
VIRUSES: They cause several diseases like influenza, rabies, yellow fever, poliomyelitis,
measles etc.

BACTERIA: They cause tuberculosis, typhoid, cholera, plague, tetanus etc.

FUNGI: They are mostly dermatophytes which cause ringworm disease. Athlete’s foot and
other skin diseases.

PROTOZOANS: They cause diseases such as malaria which is caused by plasmodium,

trypanosomiasis by trypanosoma, leishmaniasis by leishmania, amoebiasis by entamoeba
histolytica and many other.

CHAPTER 13: GASEOUS EXCHANGE

DISORDERS OF RESPIRATORY TRACT

1. LUNG CANCER:
Reason:
Lung cancer is a very dangerous respiratory disease.it is caused by smoking either actively or
passively.
Effect of smoking:
The smoke contains nicotine, SO2 etc. By their effect the epithelial cells of the respiratory
tract are damaged, their cilia are lost, so dust and germs settled inside the lungs.
Pathophysiology:
After sometime some special cells appear in the epithelial layer. These cells contain abnormal
nuclei-and thus they divide in abnormal way-so the epithelial linings of lungs are badly
damaged. These cells also penetrate into another tissues it is called LUNG CANCER.
Result:
This disease may cause death of a person.

2. EMPHYSEMA:
Disorder:
It is a disorder in which alveoli of lungs are damaged and their cells are degenerated.
Reason:
The main cause of this diseases the entrance of some poisonous toxic substances such as
nitrogen oxide (NO) and SO2 etc.
Effect on Lungs:
By the effect of these substances the lungs lose their elasticity, alveoli are ruptured and lungs
become harder. In such conditions the lungs cannot work properly, so less amount of oxygen
is supplied to different parts of the body esp. brain.
Symptoms:
The patient feels great difficulty in breathing and his breathing become labored day by day. It
also makes him lazy, depressed, irritable and sluggish.
Precaution and Treatment:
Healthy and free of pollution environment should be maintained. Effective medicines should
be used to control the disease.

3. ASTHMA:
Disorder:
It is a dangerous respiratory disease in which there are returning attacks of difficult breathing
and breath is also with wheezing sounds.
Cause:
It is caused by allergic reaction by dust, pollen grains, smoke, animal fur, cold and cough .It
may be of hereditary character i.e. It may be transferred from parents to new generation.
Result:
Due to asthma there may be contraction of bronchioles, which may be dangerous for a
patient and it may be cause death of a person.
Precaution & Treatment:
1- Use of effective medicines.
2- Free of pollution atmosphere is necessary.

4. TUBERCULOSIS
Reason:
T.B is a widespread lung disease caused by bacterium ‘Mycobacterium tuberculosis’.
Discovery:
It was first discovered by a scientist ROBERT KOCH in 1882.
Symptoms:
Its main symptoms are continuous cough, fever, laziness, loss in body weight, spitting with
blood, pain in chest, shortness of breath, sweating at night and poor appetite.
Transmission:
TB is a contagious disease and very common in poor countries. It can be transferred from one
person to another by sneezing, coughing and use of patient’s personal things .This disease
may cause death of a person.
Sources of infection:
1- Human sputum.
2- Unpasteurized milk of cattle.
Diagnosis:
Blood count, ESR test and chest X-rays are performed for the diagnosis of TB.
Treatment & Medication:
Use of effective medicines and surgery of infected part is effective in advance conditions.
Preventive & Eliminative Control:
1- Person should be isolated and kept in healthy atmosphere.
2- Personal things of a patient should not be used or shared.
3- It can be control by immunizing the infants with BCG which is used against TB.

RESPIRATION
The respiration is a complex process of oxidation reduction in which food is oxidized to
liberate energy.

RESPIRATORY MEDIA:
Definition:
The source of oxygen for living organisms is referred to as respiratory media.
Types:
There are 2 common respiratory media
1-air (for terrestrial organisms)
2-Water (for aquatic organisms)
Explanation:
Aquatic organisms obtain O2 dissolved in water while the terrestrial organisms obtain it from
the atmospheric air. The latter is the main source of O 2 on earth which contains about 21%
O2.On contrary same volume of water when fully saturated with O2 contains 5% of
O2.Morewater is denser than air. Thus it is more difficult for aquatic organisms particularly
animals to obtain O2.

PHOTORESPIRATION:
Definition:
It is a metabolic process that occurs in certain plants, in which O 2 is consumed & CO2 released
during day time.
 It occurs commonly in plants like wheat, rice, sugarcane etc.
 Such plants are called C3 plants.
 It occurs during hot and dry days.
Mechanism:
1- During hot and dry days stomata are closed to conserve water but due
to ongoing process of photosynthesis, the concentration of O2
increases than CO2 inside the leaves.
2- Under such condition, O2 competes withCO2 combine with an enzyme
called RIBULOSE BIPHOSPHATE CARBOXYLASE /OXYGENASE or RUBISCO.
3- Normally during photosynthesis Rubisco is involved in catalyzing
fixation of CO2 with RuBP to form an unstable hexose sugar. But now
RuBP combines with O2 rather than CO2 & breaks into one molecule of
Phospho-Glyceric Acid (PGA) and one molecule of phosphoglycolate.
4- The later rapidly breaks down to release CO2.
5- Equations:
RuBP + O2 ------------ PGA + Phosphoglycolate (Enzyme rubisco is used)
Phosphoglycolate----------- Serine+ CO2

Conclusion:
It is an oxidative process similar to respiration in which O2 is consumed & CO2 is released.
But it does not produce ATP. So from energy point of view it is a useless and wasteful
process.

OSMOTIC PRESSURE:
The pressure that would have to be applied to a pure solvent to prevent it from passing
into a given solution by osmosis, often used to express the concentration of the solution.

GASEOUS EXCHANGE IN PLANTS

• Gas exchange in lower plants takes place by wet body surface.
• In higher plants gas exchange through entire surface of leaves and stem is prevented
due to external, waxy covering called cuticle.
• It is an adaption to avoid excessive evaporation of water.
• The cutilarized epidermis of leaves has numerous pores called stomata for the
exchange of gases as well as evaporation of water.
• Each stoma is formed by two modified epidermal bean shaped guard cells.
• A guard cell bears chloroplast with thicker inner and thinner outer walls.
• Stomata can be opened or closed depending on the turgidity of the guard cells.
• In woody stems, lenticels are present.
• Lenticels are localized regions of loosely arranged cells with intercellular spaces
between them.
• Through lenticels respiratory gases can move freely in and out of stem.
• Gaseous exchange also occurs by roots by diffusion through epidermal cells and root
hair in the presence of moisture in the soil.

RESPIRATION IN FISH
Introduction:
The respiration in fish is aquatic respiration and breaths by means of GILLS.
Respiratory Organs:
Respiratory system of Fish comprises of Gills and other associated organs such as:
 Gill pouches
 Gill slits
 Brachial lamellae
 Opercula
Structure of GILLS:
 They are formed as outgrowth of pharynx and lie internally
within the body
 Each gill is composed of two rows of hundreds of filaments,
which are arranged in V shape or supported by cartilage or long
curved bone the GILL BAR or GILL ARCH.
 Each filament is folded to form numerous plates like lamellae
which greatly increase the surface area of the gill.
 Each lamellae is provided by the dense network of blood
capillaries.
Mechanism of Respiration:
In bony fishes ventilation is brought about by the combined effect of mouth and opercula.
The process of respiration involves the following events:
1- Water is drawn into mouth
2- It passes over the gills and ultimately exits at the back of
opercula
3- Since the concentration of O2 in water is low & also water is
denser than air , fish must use considerable energy to ventilate
its gills
4- Gas exchange is also facilitated in gills due to counter current
low of water & blood. In capillaries of each lamella, blood flows
in direction opposite to the movement of water across the gills.
5- As the water flows over the lamellae, gradually losing its O2 to
the blood, it encounters blood that is also increasingly low in
O2.
6- In this way gradient encouraging O2 to move from water into
the blood is maintained across all the lamellae.
7- Counter current flow is v. effective as it enable the fish to
extract upto 80% - 90% of O2 from water that flow over the
gills.

RESPIRATION IN BIRDS
Respiration in birds is exclusively Pulmonary. Lungs are only organs of respiration
PARTS OF RESPIRATORY SYSTEM
1- External nares
2- Internal nares
3- Larynx
4- Trachea
5- Syrinx
6- Bronchi
7- Lungs
8- Air sacs
1-External Nares:
These are pair of slit like oblique apertures.
2-Internal Nares:
External nares open into short nasal sacs which remain communicated to pharynx by internal
nares.
3-Larynx:
The Larynx is an extended, voiceless chamber which occurs at anterior most margin of
trachea & is greatly reduced in Birds. It opens into long trachea.
4-Trachea:
The trachea is a long, flexible tube running backward through neck. On entering thoracic
cavity the trachea expands into syrinx & then divided into 2 bronchi one for each lung.
One for each lung.
5-Syrinx:
It is a vocal organ one for each lung.
6-Bronchi:
Syrinx leads into bronchi. Each bronchus has structure similar to trachea & opens into lungs.
7-Lungs:
Each lung enters into bright red lung. The lungs of birds are small, compact, inelastic, highly
vascular organs. They do not store air, are solid and spongy & lie in pleural cavities.
8-Air sacs:
In addition to pair of lungs, a bird has 8 to 9 thin walled, non-vascular air sacs that penetrate
abdomen, neck and even the lungs.

RESPIRATORY MECHANISM:
The air sacs work as bellows that ensures unidirectional flow of air or COMPLETE
VENTILATION. Thus a bird must take two breaths to move air completely through system of
air sacs & lungs.
1- THE FIRST BREATH draw fresh air into posterior air sacs of lungs.
2- THE SECOND AIR pushes the first breath into anterior air sacs & then out f body. This
one way flow of air enables a bird to fly at very high altitude without shortage of O2.

RESPIRATION IN HYDRA
RESPIRATORY ORGAN:
Hydra is a multicellular animal with tissue level of organization but has no organs.
RESPIRATORY MECHANISM:
• Hydra is diploblastic, it has two layers of cells in its body.
• Most of its cells are in direct contact with water.
• Ectodermal cells exchange gases with external water.
• Endodermal cells exchange gases with water that comes with gastro-vascular cavity.
RESPIRATION IN EARTH WORM
RESPIRATORY ORGAN:
Earthworm has developed organs and systems but there are no specialized respiratory organ.
It uses its skin as respiratory structure.
RESPIRATORY MECHANISM:
• Earthworms have a thin permeable skin through which oxygen in air passes through.
• The oxygen does not directly pass through the earthworm’s thin outer skin. Instead,
the oxygen must first mix with the moist slime on the earthworm’s skin.
• It is this mixture that passes through the skin as well as the very thin tissue of
capillaries under the skin
• Earthworm has developed blood vascular system, which rapidly transport respiratory
gases within the body.

RESPIRATION IN COCKROACH
RESPIRATORY ORGAN:
Cockroach (as well as other insects) has evolved a special type of invaginated respiratory
system called tracheal system.
STRUCTURE OF TRACHEAL SYSTEM:
• A complicated system of numerous, shiny, transparent and branched air tubes or
tracheae are found for gaseous exchange in the haemocoel cavity.
• There are 6 longitudinal tracheal tubes. Chitinous rings prevent collapse of trachea.
• Atmospheric air enters into and escapes out from this system through ten pairs of slit-
like apertures called spiracles located on lateral sides of the body. Two pairs of these are
thoracic and eight pairs are abdominal.
RESPIRATORY MECHANISM:
• The cockroach takes in air directly from the atmosphere into trachea through
spiracles.
• At the level of tracheoles, oxygen diffuses directly into the cells. Hence, their blood
vascular system is devoid of haemoglobin.
• Removal of carbon dioxide from the cell depend upon plasma of the blood, which
takes up carbon dioxide for its removal through the body surface via cuticle.

RESPIRATION IN FROG
The frog has three respiratory surfaces on its body that it uses to exchange gas with the
surroundings: the skin, in the lungs and on the lining of the mouth.
1- RESPIRATION THROUGH LUNGS:
Structure of Lungs:
• In frog, lungs are simple sac-like structure with shallow internal folds that increase the
inner surface to form many chambers like alveoli.
• Alveoli are separated from each other through septa.
• The inner surface of alveoli is single cell layer and attached with blood capillaries.
• Alveoli are site of exchange of gases.
• Each lung is connected to outside by a system of hollow tubes.
• From each lung arises a tube or bronchus.
• Both bronchi open into the larynx or sound box.
• Larynx leads into the buccal cavity through glottis.

Mechanism of Lungs in Respiration:

• Frog uses positive pressure (i.e. it pushes air into the lungs) to move air in and out of
lungs.
• In order to draw air into buccal cavity, frog lowers its buccopharyngeal floor, which
causes the throat to expand.
• Then the nostrils open allowing air to enter the enlarged mouth. The nostrils then
close and the air in the mouth is forced into the lungs by raising buccopharyngeal floor.
• This type of ventilation does not allow the lungs to be completely empty or filled by
air. It is termed as incomplete ventilation.

2. RESPIRATION THROUGH SKIN (CUTANEAOUS RESPIRATION):

• While in water or buried in mud, frog respiration takes place through the skin.
• The thin membranous skin allows the respiratory gases to readily diffuse directly due
to the concentration gradient between the blood vessels and the surroundings.
• When the frog is out of the water, mucus glands in the skin keep the frog moist,
which helps absorb dissolved oxygen from the air.
3. RESPIRATION THROUGH LINING OF THE MOUTH (BUCCO-PHARYNGEAL RESPIRATION):
• Frogs also have a respiratory surface on the lining of their mouth on which gaseous
exchange takes place readily

RESPIRATION IN MAN:
Mammals including men are most highly developed animals and like all vertebrates they
possess lungs as respiratory organs.

Structure of Respiratory Organs:

1-External Nares:
The respiratory system of man begins with a pair of external nares. These are opening of
nose.

2-Internal Nares:
External nares lead into passages which open into pharynx by a pair of internal nares.

3-Pharynx:
It is a common passage of food as well as air.

4-Larynx:
Pharynx leads air into larynx
through an opening called
glottis. Glottis is guarded by a
flap of tissue called epiglottis.
Larynx or voice box is a small
chamber consists of a pair of
vocal cord for producing sound.
Larynx leads into trachea.

5-Trachea:
Trachea or wind pipe is a tube
lined with ciliated epithelium. Its
lining produce mucous, secreted
by goblet cells.
 6-Bronchi:
Trachea divides into two bronchi. Each bronchus leads air into lungs of its side.

7-Bronchioles:
Each bronchus enters lungs and in turn divides repeatedly to form numerous bronchioles,
these bronchioles terminates in group of tiny air sacs or alveoli.

8-Lungs:
 Lungs are paired, soft, spongy structures.
 Right lung is partitioned into three lobes while left lung into two lobes.
 Each lung is enclosed by pleural membranes
 Within pleural membranes, there is fluid filled narrow cavity called Pleural cavity.

9-Air sacs (Alveoli):

 The alveoli are considered as respiratory surfaces of lung.

 The internal area of alveolus is provided with a thin layer of fluid containing
surfactant. It reduces internal surface tension to prevent it from collapse during
gas exchange.

MECHANISM OF BREATHING:
It involves two phases:
1-Inspiration
2-Expiration

1- INSPIRATION:
 It is an active process, caused by contraction of muscles of diaphragm.
 The action of diaphragm and intercostal muscles of ribs increase size of thoracic
cavity which results in negative pressure in thoracic cavity.
 Then air rushes in through external and internal nares into entire trachea and
finally into alveoli of lungs.
 As alveoli fill with air, the lungs expand and increase in volume.
 The O2 inhaled diffuses into blood in capillaries of alveoli.
 The O2 combines with haemoglobin in RBCs.
 Simultaneously CO2 diffuses into air contained in alveoli it is expelled from body
during expiration.
 The oxygenated blood is carried away from the lungs to the heart for distribution
to various parts of body.

2- EXPIRATION:
 It is caused by relaxation of muscles of diaphragm and intercostal muscles.
  The volume of thoracic cavity decreases and air is forced out of the lungs.
 The O2, CO2 and water vapor contents of inhaled air is very different from that
exhaled air.

LUNG CAPCITY
 Total Capacity:
The total average lung capacity of adult human being is about 5 liters (5000 cm 3) of air.
 Tidal Capacity
 During normal breathing a person takes in and gives out air approximately half of
a liter (450-500 cm3). This is called tidal volume. It is only about 10% of the total
capacity of lungs.
 Vital Capacity:
With an extra deep breath, the maximum volume of air inspired and expired is called vital
capacity averages about 4 liters.

 Residual Volume:
The remaining volume approximately 1 liter of air remained in the lungs is termed as residual
volume. It remains in there due to the fact that thorax cannot collapse completely. Residual
volume is not stagnant since inspired air mixes with it each time. Aging, emphysema etc can
increase the residual volume at the expense of vital capacity.

1- TRANSPORT OF OXYGEN
Oxygen is transported in body via blood. Two types of components haemoglobin and
myoglobin play very important role in transport of O2.

Role of Haemoglobin:
Haemoglobin, an iron containing protein is a respiratory pigment in the red blood corpuscles
of vertebrates.

Chemistry of haemoglobin:
 Each Hb molecule has 4 iron containing groups called HAEME.
 It is the IRON which reversibly binds with O2
 Nearly, all O2 carried by blood is bound to Hb.
 Due to Hb, blood could carry 70 times more O2 than plasma, so it plays an
important role in maintain high concentration gradient of oxygen from air to
blood.

Action of Haemoglobin:
 Hb binds to O2 to form a loose compound called oxyhaemoglobin
 It is carried to the tissues where due to low concentration of O 2 in tissues,
oxyhaemoglobin dissociates releasing O2 which enters in tissues
 The whole process can be represented by equation
Hb + 4O2<====== Hb (O2)4
Myoglobin, a smaller protein than Hb, found in muscles can bind to oxygen more tightly than
Hb. It gives red colour to muscles.

2- TRANSPORT OF CARBONDIOXIDE:
Carbon dioxide, produced as an end product of cellular respiration, diffuses out into the
blood plasma through the tissue fluid. There are three methods of CO 2 transport.
i. About 5% CO2 is carried as carbonic acid in the plasma, which soon dissociates
 into hydrogen and bicarbonate ions.
 Hydrogen Ions:
Hydrogen ions are taken over by ammonia of plasma to forming ammonia.
 Bicarbonate Ions:
Bicarbonate ions are hooked up with sodium ions to form sodium bicarbonate.
H2O + CO2 <====== H2CO3 (Carbonic Acid)
H2CO3 <====== H+ + HCO3- (Bicarbonate)
HCO3- + Na+ <====== NAHCO3 (Sodium bicarbonate)
 At the lung surface all the reactions are reversed freeing CO 2 and H2O.
 The CO2 passes out into the alveolar air.

ii. About 60% CO2 with the water of R.B.Cs and catalyzed by an enzyme carbonic
anhydrase. The resultant carbonic acid dissociated into H+ ions and HCO-3 ions. The
bicarbonate ions combine with potassium ions forming potassium bicarbonate
which is carried to the lungs.
H2O + CO2 <====== H2CO3 (Carbonic Acid)
H2CO3 <====== H+ + HCO3- (Bicarbonate)
HCO3- + K+ <====== KHCO3 (Potassium bicarbonate)

iii. The remaining 35% of CO2 combines with the amino groups of haemoglobin to
form loose compound, carbamino heamoglobin. It is carried to the alveolar
surface where CO2 dissociates from carbamino compound and escapes into the
alveolar air.

RATE OF BREATHING:
VOLUNTARY CONROL:
We can hold our breath for a short period of time or can breathe faster and deeper at our
will. This is termed as voluntary control.
INVOLUNTARY CONTROL:
• Rate of breathing is controlled automatically. This is termed as involuntary control.
• It is maintained by coordination of respiratory and cardiovascular system.
• Increased concentration of carbon dioxide and H+ ions in blood are basic stimuli to
control the rate of breathing.
• Their concentration are monitored by aortic and carotid bodies situated in aorta and
coronary arteries respectively.
• Any change in concentration of carbon dioxide and H+ ions is detected by medulla
oblongata.
• Medulla oblongata is itself sensory to changes in concentration of carbon dioxide and
H+ ions present in cerebro-spinal fluid.
• In response to, increase concentration of carbon dioxide and H+ ions it sends
impulses to inter- coastal muscles and diaphragm to increase breathing rate.

CHAPTER: 14 TRANSPORT
TRANSPORTATION:
Transportation is concerned with the transfer of digested food molecules along with water,
salt & vitamins to those parts where it is needed.

UPTAKE & TRANSPORT OF WATER & MINERALS:

Soil is the source of water & minerals for plants. These are taken up by roots. Various
processes are involved in uptake of these minerals. These are:
  Diffusion
 Facilitated diffusion
 Osmosis
 Imbibitions
 Active transport

DIFFUSION:
The movement of molecules from the region of higher concentration to the region of lower
concentration is called diffusion.

FACILITATED DIFFUSION:
The process of diffusion across the membrane whose permeability is enhanced by special
carrier molecules is referred to as facilitated diffusion.

OSMOSIS:
It can be defined as movement of solvent molecules from the region of higher solvent
concentration to the region of lower concentration through the semi permeable membrane.
Types:
1-Endosmosis 2- Exosmosis
1-Endosmosis:
The inflow of liquid of lower concentration through the semi permeable membrane is called
endosmosis e.g. Entrance of water into cells from its environment.
2-Exosmosis
The outflow of liquid from the interior of the cell when it is placed in solution of higher
concentration is called Exosmosis.

ACTIVE TRANSPORT:
Definition:
The process of transport of ions or molecules across a membrane against concentration
gradient in which expenditure of energy takes place is known as active transport.
Examples:
1-Sodium-potassium pump is an e.g. of active transport in animals.
2-in plants, phloem loading is an active translocation process

IMBIBITION:
Definition:
Absorption of water and swelling of hydrophilic (water loving) substances is imbibitions.
Explanation:
It is a process of sucking up of water by certain materials, particularly in dry or semi dry
condition. Substances such as starch, gums, protoplasm, cellulose & proteins have great
affinity for water & are called Hydrophilic .Living and dead plants are hydrophilic colloids as
they possess large amount of carbohydrates & as such they have strong affinity for water.
Examples:
 Seeds which have v. low water potential swell up when placed in water.
 Wrapping up of wooden framework during rainy season.

Essential Condition for Imbibition:

Only those substances exhibit imbibitions which have an affinity for water. Rubber does not
swell when placed in water on the other hand swelling of dry seeds in water & wrapping up
of wooden doors during rainy season are common examples of imbibition
Imbibition Of Cells:
The cell wall and protoplasm are also able to absorb water by imbibitions & play an important
role in physiology of plant life.

PLASMOLYSIS:
Definition:
It is defined as shrinkage of protoplasm due to exosmosis of water.

Explanation:
 Under normal conditions the cell sap possesses the protoplasm against cell wall.
 The cell sap possesses a certain osmotic pressure, when cell is placed in an
external sol. Of higher concentration (higher osmotic pressure) water begins to
pass out the cell by osmosis (exosmosis) with consequent shrinkage in the volume
of vacuole & ultimately whole of protoplasm. This phenomenon is called as
plasmolysis.
 Eventually, the cytoplasm begins to separate from cell wall leaving a noticeable
gap between cell wall and cell membrane.
 The point when cytoplasm first starts to separate from cell wall is called incipient
plasmolysis.
 When protoplasm completely separates from cell wall, full plasmolysis achieved.
 In a plasmolysed cell ѱp is zero (pressure potential)
Ѱ=ѱs
(Water potential)= (solute potential)

DEPLASMOLYSIS:
Definition:
When a plasmolysed cell is placed In pure water, endosmosis occurs. As the result of which,
the cell again becomes turgid. This recovery from plasmolysis is called deplasmolysis.

Explanation :

When a plasmolysed cell is placed in pure water, or hypotonic solution, water begins to flow
into the vacuole by endosmosis.
 Protoplasm expands gradually & presses the cell wall.
 Pressure potential begins to develop.
 With rise in temperature potential water potential also increases becoming less
negative.
 Eventually the cell becomes turgid, this recovery of cell from plasmolysis is known as
deplasmolysis.
WATER POTENTIAL
DEFINITION:
It is defined as potential energy of water and it is measure of the capability to release or
uptake water relative to another substance.
Notation:
It is denoted or symbolized as greater letter Ѱ (psi) and expressed in pressure unit such as
mega Pascal.
Dependence:
It is relative quantity and depends upon concentration, pressure and gravity. This relation
may be written as
Ѱ = Ѱ +f concentration + f pressure + f gravity

Osmotic/Solute Potential:
Definition:
The pressure exerted upon a solution to keep it in a equilibrium with pure water when the
two are separated by a semi-permeable membrane is known as Osmotic Potential.
Representation:
It is represented by Ѱs

Pressure Potential:
Definition:
Pressure potential is defined as the effect that pressure has on water potential.
Notation:
It is denoted by Ѱp.
Quantitative expression:
The relationship between water potential, solute potential and pressure potential is
represented by following equation.
Ѱ = Ѱs + Ѱp
In a turgid cell pressure potential is equal and opposite of solute potential, so
Ѱ=0

Water & Mineral Uptake by Root:

The movement of water and dissolved minerals, from roots to the highest parts of plant is
very systemic. It involves following events and stages:
i. Absorption Through Roots:
 The absorption of water and salt does not take place from entire surface of
root but only through root hairs.
 The absorption occurs not only by osmosis but many other processes such as
imbibitions, turgidity, diffusion etc.

Characteristics of Root System:

1. Roots are provided by exosmosis, number of tiny hairs, which are outgrowth of
epidermal cells and found at the root tips.
2. The root hairs greatly increase the surface area of root.
3. Because of large surface area plants absorb enough quantities of water and
inorganic ions for their survival and growth.
Mechanism:
Root hairs possess sticky walls and adhere tightly to soil particles which are usually coated
with water and dissolved mineral salts. Most of absorption takes place near the root tip
where epidermis is permeable to water and root hairs. From root hairs and epidermal cells
water flows through cortex, endodermis, pericycle and enters system. Since transport of
water takes place in radial direction, it is also termed as Lateral Transport.

ii. Internal Movement Of Water & Minerals:

There are three pathways for water to enter system. These pathways are:
1- Cell to cell pathway
2- Symplast pathway
 3- Apoplast pathway

1- Cell to cell pathway:

 First route is from cell to cell.
 Water enters root hairs down a gradient of water potential.
 It flows out of one cell across the cell wall & cell membrane and enters the
adjacent cell.

2- Symplast pathway:
In this water moves from cell to cell through tiny pores plasmodesmata on cell wall.
 Through the pores in cell wall, cytoplasm of cortical cells remains connected
with cytoplasm of adjoining cortical cells. These cytoplasmic connections
through pores are known as Plasmodesmata.
 These cytoplasmic connections provide another pathway for transport of
water and solutes known as Symplast Pathway.

3- Apoplast Pathway:
 In this pathway water moves through the cell wall, within the cellulose of
adjacent cells and through the small intercellular spaces.
 Soil solution flows freely through hydrophilic walls of epidermal and cortical
cells. This movement of soil solution through extracellular pathway provided
by continuous matrix of cell walls is known as apoplast pathway.
 As solutes more along extracellular pathway some of the water and solutes
are taken up by the cells of cortex thus changing the route from apoplast to
symplast pathway.

Ascent of Sap
Definition:

‘The ascent of sap in the xylem tissue of plants is the upward movement of water and minerals
from the root to the crown. Xylem is a complex tissue consisting of living and non-living cells.
The conducting cells in xylem are typically non-living and include, in various groups of plants,
vessels members and tracheid’.

In ascent of sap, there are two important aspects:

a. Path of ascent of sap.
b. Mechanism of ascent of sap.

a. PATH OF ASCENT OF SAP:

“The water absorbed by the roots of a plant is conducted upward to the leaves through
xylem”
Structure of Xylem: It is a complex conducting tissue responsible for the conduction of water
and dissolved minerals from roots to leaves.
Xylem is composed of four different types of elements which are:
1- Tracheid
2- Vessels
3- Wood parenchyma
4- Wood fibers

1- Tracheid:
  These are elongated dead cells, placed end to end in longitudinal row.
 The tracheids have hollow cavities with permeable cell walls with many pits
 In many case, the pits in two adjoining cells are exactly opposite to each other.
 Due to their water dissolved inorganic salts can easily pass from one trachied
into another through these thin called areas.

2-VESSELS:
 These are elongated tube like cylindrical hollow dead cells with no transverse
walls.
 They are placed end to end in longitudinal rows, forming a structure just like
an open water pipeline. Therefore, the vessels are much more efficient
conducting structures than are tracheid.
 But the trachieds and vessels form a connected system of conducting
channels running from the roots up through the stem and into the veins of
the leaves.

3-WOOD PARENCHYMA:
It is living tissue, which stores water and dissolved inorganic salts.

4-WOOD FIBRES:
These are the dead sclerenchymatous cells, which provide rigidity and support to the
elements of xylem.

MECHANISM OF ASCENT OF SAP:

Water and dissolved mineral salts present in xylem (sap) flow in upward direction at the rate
of 15 meter per hour. Xylem sap ascends against the downward pull of gravity without the
help of any mechanical pump. The rise of sap in xylem is either due to push from below or a
pull from above. The contribution of two possible mechanisms is as follows:

PUSH FROM BELOW- ROOT PRESSURE:

This theory explains that root pressure originates in the roots and is responsible for forcing
up water from root to leaves. This pressure is generation by the osmotic pressure of the
cortical cells of the root.

DISCOVERY:
Thus root pressure is discovered by Stephen Hales in 1727. According to Hales, this force
could be responsible for raising water to a height of 6.4 meters. He also observed that the
pressure develops at certain times of a year.

GUTTATION –EFFECT OF ROOT PRESSURE:

Root pressure also causes guttation.
 The exudation of water droplets can be seen on the tips of glass blades and
leaf margins of small herbaceous dicot plants.
 During night when the rate of transpiration is very low the root pressure
pushes xylem sap into shoot system. More water enters leaves than is
transpired.
 The excess of water is forced out in the form of droplets through openings
called hydathodes
.
OBJECTIONS:
 The root pressure is not sufficient to raise water to enough height and is only
adequate to force up water in herbs.
 Root pressure also shows seasonal variations. In spring it is high due to low
transpiration and is lower in summer when the transpiration is active.
 If a cut shoot is dripped in water it will be observed that it doesn’t wilt. This
proves that water moves up even in the absence of root and thus without root
pressure.

TRANSPIRATION PULL (ADHESION-COHESION-TENSION THEORY):

Ascent of sap mainly depend upto two factors. These are:
1-Transpiration which generates pulling force and
2-Physical properties of water of water i.e. adhesion and cohesion. Adhesion is the sticking
together of molecules of different kinds and cohesion is the clinging together of molecules of
same kind. The cohering water molecules in xylem vessels form a continuous column.
 Transpiration pull results from chain of events that starts when leaves begin to
absorb solar radiation in the morning.
 Sunlight raises temperature of leaves so the water begins to evaporate from moist
walls of mesophyll cell.
 The evaporated water is immediately replaced with water from neighboring cell
deeper in leaf.
 Ultimately, water is pulled from xylem to meet the loss of water.
 Thus water in xylem is replaced under tension which is transmitted to root
through vessel.
 This downward transmission of tension is because of cohesive property of water
columns in vessels and tracheids water column moves upward by mass flow due
to transpiration pull.
 Adhesion of water molecules to hydrophilic walls of xylem cells small diameters of
vessels and tracheids are important factors in overcoming the force of gravity.
To transport water over a long distance, plant does not use their metabolic energy.
Forces like adhesion, cohesion and evaporating effect of sunlight are mainly responsible for
upward conduction of water. Thus ascent of sap is solar powered.

TRANSPIRATION:
“Transpiration can be defined as the loss of water from the aerial parts of plant in the form of
water vapours.”
Plants absorb large quantity of water from soil. Only 1-2% of absorbed water is used in
photosynthesis, in other metabolic activities and in maintenance of turgor cells. The
remainder is lost from leaves and other aerial parts in the form of vapors i.e. transpiration.

Types of Transpiration:
There are three types of transpiration.
1- Stomatal transpiration
2- Cuticular transpiration
 3- Lenticular transpiration

1- Stomatal transpiration:
In lamina of leaf there are microscopic pores known as stomata. Through these pores water
in vapor form escapes into outer atmosphere. This loss of water in vapor form through
stomata is known as stomatal transpiration. Since greater loss of water takes place through
stomata. Therefore, leaves are regarded as chief transpiring organ.

2- Cuticular transpiration:
Cuticle is layer of waxy substance cutin found outside the epidermis of leaves and stems. Loss
of water in vapor form from epidermal cells through cuticle is known as cuticular
transpiration.

3- Lenticular Transpiration:
Lenticels are also pores found in old dicot stems
which are formed as a result of secondary growth.
Smaller quantities of water are also given out
through lenticels. This is known as lenticular
transpiration.

Mechanism of Stomatal Transpiration:

Two processes are involved in this type of
transpiration
1- Diffusion
2- Evaporation

Water absorbed by roots is conducted to aerial parts (leaves) through xylem. Mesophylls cells
of leaves are supplied with water through xylem (veins).then mesophyll cells are turgid. Their
walls remain saturated with water and are in contact with intercellular spaces, which are
connected with outer atmosphere through stomata .in the first step water evaporates from
wet surfaces of turgid mesophyll cells. The vapours are collected in intercellular spaces and
then water vapours diffuse out of intercellular spaces (where they are in higher
concentration) to atmosphere (where they are in lower concentration) through stomata.

Structure of Stomata:
Stomata are the microscopic pores present in the epidermis of leaves and herbaceous stems.
Each stoma is bordered by two modified epidermal cells called ‘Guard cells’. These guard
cells unlike epidermal cells are provided with chloroplasts and shaped like kidneys. In general,
the stomata remain open during day time and become close at night. Thus light appears to
be the prime factor which initiates opening of stomata.

Mechanism of opening and closing of stomata:

The opening and closing of stomata depends upon turgidity of guard cells, which is due to
increase or decrease of osmotic potential of the guard cells. The changes in water potential
that results from the osmotic changes cause water to move in or out, they go placed. When
guard cells are turgid, the stomata is open, when the guard cells are flaccid, the stomata is
closed. To effect this movement of water an exchange must take place between the guard
cells and the surrounding mesophyll and epidermal cell.

Factors Affecting Opening and Closing Of Stomata:

There are 2 main factors which greatly influence the opening and closing of stomata. These
are:
 Light: the stomata of a leaf are open when exposed to light and closed
when darkness returns .in the presence of light; chlorophyll containing
guard cells synthesize sugars which in return increase the osmotic
potential of guard cell. The increase result in endosmosis and ultimately
to turgidity. While in darkness these guard cells consume carbohydrate
or these carbohydrate are translated to neighboring cell which decrease
the osmotic potential in guard cells. The decrease results in exosmosis
which ultimately leads to flaccid.
 Concentration of K+ ion: during day time guard cells actively transport
K+ ion from neighboring cells. Accumulation of K+ ion lowers the water
potential of guard cells. This causes in flow of water by osmosis from
epidermal cells. When they lose K+ ions water potential increases water
flows out of guard cells causing them to become flaccid which result in
closure of pore.

Factors affecting Transpiration;

 Light: It is one of the most important factors because it regulates the
opening and closing of stomata. The stomata remains wide open during
day time, as a result transpiration takes place through them. But at
night they are closed, hence the transpiration is greatly check.
 Temperature: The increases in temperature increase the rate of
transpiration by increasing the rate of evaporation of water from cell
surface.
 Humidity: Transpiration decreases with the increase in humidity
(moisture of air) and increases with the decrease in humidity. It means
that transpiration takes place only when the atmosphere is potentially
saturated or dry. The difference in the water content of the plant and
that of atmosphere affects the rate of transpiration.
 Wind: The increase in the wind velocity increases the rate of
transpiration by removing the water vapours surrounding the plants.
 Soil water; A plant can’t continue to transpire rapidly if moisture loss is
not made up by absorption of fresh supplies of water from soil. When
absorption of water by roots fails to keep up with the rate of
transpiration loss of turgor occurs and wilting of leaves lake place.

Significance of Transpiration:
Transpiration is of great importance in many ways:
 Roots continuously absorb water from the soil and thus the water is
several times in excess of the need of plant. The excess is got rid by the
transpiration.
 When the transpiration is greater than the rate of absorption of water is
increased.
 Absorption of water helps in intake of inorganic salts from the soils,
which are used in the food manufacture.
 Transpiration maintains the concentration of cell and thus helps
osmosis.
 As a result of transpiration from the leaf surface a suction of force is
generated which helps the water to ascend to the top of lofty trees.
  Transpiration helps in distribution of water throughout the plant body.
 Because of the loss in heat due to evaporation the process of
transpiration is said to cool the plants, which are exposed to bright
sunlight.

Disadvantage of Transpiration:
 Sometimes unnecessary transpiration causes the death of plants.
 Some plants are in habit of shedding their food organs (leaves) in order
to reduce the rate of transpiration during unfavorable season.
 In some plants leaves are modified into scales or spines in order to
minimize the rate of transpiration.

TRANSLOCATION OF ORGANIC SOLUTES:

The products of photosynthesis move from mature leave to the growing and storage organs
of plants. The direction of transport is determined by relative locations of the sources and
sinks of photosynthesis. This movement of photo assimilates and other organic materials take
place via the phloem and are therefore called phloem translocation.
Transport occur in specialized tissue called ‘sieve elements’
“Process of transportation of manufactured food to the various parts is called translocation”.
SOURCE-SINK MOVEMENT:
The translocation of photosynthesis always takes place from source to sink tissues therefore
this phloem transport is also referred as source to sink movement.
This pathways followed developmental changes as some sink and source tissues are
interconvertable during the development of plants E.g.; developing and germinating seeds,
developing and mature leaves. A number of steps are involved in the movement of
photosynthates from mesophyll chloroplasts to the sieve elements in the phloem of mature
leaves. These steps are discussed below:
1-sucrose is synthesized in the cytosol of the mesophyll cells
2-this sucrose is translocated from mesophyll cells to the vicinity of the sieve elements in the
smallest veins of the leaf. This is generally termed as short distance transport pathway
because the solutes cover only the distance of two or three cells diameter.
3-the sucrose is then actively transported into sieve elements in a step commonly called
phloem loading.
4-the pathway of phloem loading may be either symplastic or apoplastic depending upon the
species.
5-the sucrose in sieve elements is exported away from source tissues. The photo assimilates
can be moved along distance hence it is termed as long distance transport.
6-finally the photo assimilates or sucrose is unloaded in a sink in a process referred to as
phloem unloading.

IMPORTANCE OF SOURCE SINK MOVEMENT:

The driving force for this translocation of photosynthesis is believed to be generated by the
process of phloem loading and unloading. Therefore, this source of sink movement has great
agricultural importance; because the productivity of a crop could potentially be increased by
increasing the accumulation of photosynthates in edible sink tissues like cereal grains.

MECHANISM OF PHLOEM TRANSLOCATION:

Although several theories are considered to be responsible for the process of translocation of
organic substances here will be describe only MUNCH HYPOTHESIS also called PRESSURE
FLOW HYPOTHESIS.
PRESSURE FLOW HYPOTHESIS:
Phloem translocation is mainly explained by a theory called pressure flow hypothesis
proposed by Ernest Munch in 1930 which states that flow of solution in the sieve elements is
driven by a pressure gradient produced due to differences in osmotic pressure between
sources and sinks. This pressure gradient is produced due to phloem loading and unloading at
the source and sink respectively. The main steps of the hypothesis are given below:
 A high osmotic pressure is generated due to active phloem loading in the
sieve elements of the source tissue, causes decline in the water potential.
 In response to this decline in water potential, water enters into sieve
elements and produces a high turgor pressure.
 In the sink tissues, present at the other terminal of the translocation pathway,
phloem unloading occurs, which produces a low osmotic pressure in the sieve
elements of the sink tissues.
 As a result of this low osmotic pressure, the water potential of the phloem
rises above that of xylem and water tends to leave the phloem in response to
the water potential gradient which causes the decrease in the turgor pressure
of phloem sieve elements of the sink.
 An equilibrium between the two ends (source and sink pressure) would be
reach v. soon if the entire translocation pathway were a single membrane
bounded compartment.
 The sieve plates which are present
in sieve elements increase the
resistance along the pathway and
maintain the pressure gradient in
the sieve elements between
source and sink.
 The sieve elements contents are
physically pushed along the
translocation pathway by bulk
flow, much like water flow through
a garden house.
 Water movement in the
translocation pathway is therefore
driven by the pressure gradient
rather than the water potential
gradient.
 The passive pressure driven long
distance translocation in the sieve tube ultimately depends on the active
short distance transport mechanism involved in phloem loading and
unloading.
 These active mechanisms are responsible for setting up the pressure gradient
in the first place.

TRANSPORT IN ANIMALS:
Transport in Hydra:
 Hydra is the simplest multicellular animal. It is composed of two layers, ectoderm and
 endoderm, with a non-cellular mesoglea in between.
 The gastro vascular cavity (coelenteron) serves for the dual functions of digestion and
distribution of substance throughout the body.
 The both inner and outer layers are bathed by water.
 It possess a large surface to volume ratio so the diffusion is sufficient for the
transportation of digested food, oxygen, CO2 and other metabolic wastes,
Transport in Planaria:
 It is a triploblastic and a complex animal with a dorsoventrally flattened body.
 Gaseous exchange takes place by direct diffusion across the general body surface.
 Planaria possess an extensively branched intestine. These branches reach very close
to the cells of the body. The digested food is pumped into the branches by muscular
action of digested tube. So the nutrients reach directly to the cells and diffuse into
them.
 It has no circulatory system for transportation. However, one special transport system
is present to dispose of the excess amount of water along with nitrogenous waste (
protonephridia).

EVOLUTION OF HEART IN VERTEBRATES:

In the evolution of heart many changes have taken place.
- In fishes, the heart is S-Shaped having only two chambers. The atrium receives the blood
through through a thin walled chamber of the veins, the sinus venosus that opens into
ventricle which pump the blood through arteriosus a chamber of aorta in to the body.

- In amphibians, the heart is tri- chambered: two aorta and one ventricle. The right atrium
receives deoxygenated blood from the body and left atrium receives oxygenated blood from
the lungs. But these two types of blood get mixed in ventricles, to some extent.

- In reptiles, the same tri-chambered heart is found with a beginning of the partition of the
ventricle by inter ventricular septum.

-Birds and Mammals have four chambered heart. Two atria and two ventricles. The two types
of blood remain separate. The oxygenated blood circulates through the left side and the
deoxygenated through the right side. This brings about a complete double circulation.

S - A node:
 The stimulus for contraction of the heart originates in a specific region of the right
atrium called Sino-atrial node (S –A node) close to the point of entry of the superior
vena cava.
 It consist of cardiac muscle fibers, possessing few myofibrils and a few nerve endings
of the autonomic nervous system.
Pace Maker:
 The S-A node initiates the heartbeat. Thus it is known as pace maker because each
wave of excitation for the contraction of atria begins here, and acts as the stimulus
for the next wave of excitation.
A-V Node:
 The tissues of the A-V node are similar to those of the S-A node.
 It is located in the atrium below S-A node.
 They are stimulated by the wave of excitation send by S-A node. Its excitation travels
all parts of the ventricles through two bundles of specialized muscle fibres of the
bundle of His in the ventricles, through a network of fibres called purkinje fibres.
  There is a delay of about 0.15 seconds in conduction from the SA node to AV node
permitting atrial systole to be completed before ventricular systole begins.

GENERAL CHARACTERISTICS OF CIRCULATORY SYSTEM:

The characteristics of circulatory system are as follows:

 It has circulatory fluid, the blood.

 The blood is pumped by a contractile device around the body which maybe modified
blood vessel or a heart.
 The blood circulates through the tubes which are known as blood vessels.
 It has one way valves to keep the medium flowing in one direction.

Types of Circulatory System:

The blood circulatory system is basically of two types: open type and closed type. They both
allow the transported material to be exchanged between the blood and the cells.
a) Open type circulatory system:

 The blood circulates within the open body sinuses and bathes the surrounding tissue.
These sinuses are collectively called as haemocoel.
 Since there is no distinction between blood and interstitial fluid, so the general body
fluid is more correctly known as haemolymph.
 The blood is pumped by the heart which propels it into arteries. The arteries open
into blood sinuses from where it is driven back to the heart.
 Since the blood flows within the sinuses and comes in direct contact with the body
tissues, the system is known as open type circulatory system.
 The open type circulatory system is found in arthropods, molluscs and tunicates.

b) Closed type circulatory system:

 The blood circulates through closed blood vessels and is distinct from the
interstitial fluid. It does not come in direct contact with any tissue.
 The blood is pumped by the heart rapidly around the body under sustained
high pressure and backt to the heart. The distribution of the blood is
controlled.
 Exchange of materials occurs across the walls of blood capillaries, which
ramify through the organs and come into close association with the body cells.
 A disadvantage of closed type circulatory system is that the vessels form a
barrier between the blood and the surrounding tissue cells. The transporting
material have to pass through this barrier.
 It is found in annelids, echinoderms, cephalopods and vertebrates.

BLOOD:
Blood is a red coloured fluid found in the body of man and other animals. It is connective
tissues and composed of two constituents.
i. Plasma
ii. Blood corpuscles.

Plasma:

NATURE:
Plasma is a liquid & non-living. It consists about 55% of the blood.

COMPOSITION:
The water is most abundant component and forms 90% of plasma. The dissolved substances
are only 10%. It also contains various organic and inorganic substances in solution.
INORGANIC:
These are chloride, bicarbonate, sulphate and phosphate.
ORGANIC:
These include plasma, protein, glucose, amino acid, hormone, enzyme and waste products.
Blood Cells:
It consist three types of cells
i. Erythrocytes
ii. Leucocytes
iii. Platelets

 RED BLOOD CELLS:

These corpuscles are also called erythrocytes.
Structure :
They are circular oval shaped, biconcave and without nucleus. Their average diameter is 7-
8µm.

Constitution:
They contain a red protienaceous pigment called haemoglobin due to the presence of this
pigment they are of red colour.

POWER OF ACTION:
It absorbs oxygen and carries it to all cells and tissues of the body. Haemoglobin is an iron
containing compound, when it absorbs oxygen, it is changed into oxy-haemoglobin which is
bright red in colour.
Formation: They are found in bone marrow of sternum ribs etc.
Life Period: The life of erythrocyte is limited, in frog they live for about hundred days but in
man about 120 days. The iron is retained and rest is passed as bile pigments bilirubin, and
biliverdin.

FUNCTION: They help in the transport of oxygen. They also contain an enzyme carbonic
anhydrase which plays a role in carbon dioxide transport.

 WHITE BLOOD CELLS:

These are also termed as leucocytes.
Structure:
They are colourless, without any regular shape and contain a nucleus Majority of them are
larger than R.B.Cs but they are less in number.
Nature:
They can move independently through the intercellular spaces among the tissues by
amoeboid movement.
Factor Of Existence:
Their number in body depends upon the physiological conditions of the body.
Region Of Formation:
They are formed in bone marrow, spleen, thymus and lymph nodes.
LIFE PERIOD:
They have a short and very limited life period and destroy within 20-30 hours.
TYPES:
They are of two types
i. Granulocytes
ii. Agranulocytes.
They have clear cytoplasm without granules e.g. lymphocytes & monocytes. The lymphocytes
produce antitoxic substances to neutralize toxic effect.
The monocytes also absorb bacteria and other foreign particles to destroy them.

 PLATELETS:
They are also termed as thrombocytes
Structure:
They are smaller, oval shaped colourless, biconvex and non-nucleated cells.
Size Range:
They are much smaller than red blood corpuscles or W.B.Cs. They are fragments of bone
marrow cells.

FUNCTION:
They help in blood clotting b/c they have an ability to form thrombus on exposure to air or on
contact with rough surface.
 FUNCTION OF BLOOD:
Blood is special connective tissue meant for transportation. There are many function of
blood. Some are performed by plasma and some are performed by blood corpuscles.

Function Of Plasma:
Nutritive transportation:
Blood take part in transportation of food, water and other important substances from
alimentary canal to the different parts of the body for much purpose such as storage,
oxidation, and assimilation.
Removal of wastage:
Plasma of the blood picks up all the metabolic wastes like urea and uric acid from various
parts of the body and takes them first to the liver and then to the kidneys from where theses
are eliminated out.
Transport of Hormones:
Blood also helps to transfer the important hormones from endocrine glands to those parts of
the body where they are required.
Carrier Of Metabolic By-Products:
Blood also takes part to transfer many by-products produced in different parts during
metabolism to other parts of the body.
Distribution of Body Heat:
By the circulation of blood, heat is distributed throughout the body, to maintain the body
temperature constant and uniform.

FUNCTION OF RBCs:
Transport of O2 & CO2: the blood circulation also helps in the exchange of gases. O2 is
transported from lungs to other parts of the body and CO2 is carried from body to the lungs
for its removal.

FUNCTION OF WBCs:
Defence against diseases: WBCs are responsible for the defence of body against diseases.
They kill the germs. They also produce antibodies and antitoxins to protect the body.

FUNCTION OF PLATELETS:
Healing of wounds: Platelets take part in the clotting of blood after any injury, otherwise it
may be dangerous for the body.

BLUE BABIES:
Preface: It is a lay man terminology. In medical science it is known as cyanosis. (Cyano-blue,
sis-process)

Discolouration of Skin:
Cyanosis is a bluish discolouration of skin & mucous membrane due to excessive
concentration of reduced haemoglobin in the blood.

Reason: Cyanosis is due to the mixing of blood between two atria or between two ventricles.
The main reason of mixing oxygenated and deoxygenated blood is defect in the atrial septum
ASD or VSD (ventricular septum defect). The common cause is cyanotic heart disease.

Induction of blue appearance:

When oxygenated and deoxygenated blood are mixed, there is excessive concentration of
reduced haemoglobin in the blood. It shows blue skin colour.

HEART BEATS:
Definition: when chambers of heart contract in systematic and regular manner it is called
heart beat.

Heart Sounds:
A normal heart beat shows heart beats 72 times per minute. These heart beats are called
heart sounds, because these beats can be listen easily.
Mechanism of Heart Beat:
Production of LUB: In the heart beat when the ventricles show systole, blood is forced
against the closed artrio-ventricular valves. It produces first heart beat sound (LUB).
Production of DUP: After systole the ventricles show diastole. In the pulmonary and
systemic aorta high pressure is developed it forces some blood back towards the ventricles
which closes the valves of both aorta, this process produces the 2nd heart beat (DUP).
Time period: one complete heart beat consists of one systole & one diastole & lasts for
about 0.8 second.
Detection of Heart Murmur: a defect in one or more of the valves causes a condition known
as heart murmur; this may be detected as a sound called hissing sound.

LEUKEMIA:
 Leukemia is the malignant disorder of the haemopoetic tissues, associated with
increased number of leucocytes in the blood.
 They obstruct normal blood cell formation in bone marroe.
 They are progressive and fatal conditions resulting in death, most often from
hemorrhage or infection.
 Several factors however are associated with the development of leukemia like
ionizing radiation, cytotoxic drugs, retrovirus, genetics etc.
THALASSAEMIA:
 Thalassemia is an inherited impairment of haemoglobin production.
 When the abnormality is heterozygous, the synthesis of haemoglobin is only mildly
affected and little disability occur. Synthesis is grossly impaired when the person is
homozygous.
 Failure to synthesize beta chains is the most common type.
 Homozygotes are either unable to synthesize haemoglobin or produce very little
amount, a condition called thalassemia major. it is more common in children. It
results to the enlargement of kidney. The regular blood transfusion is the only
remedy.


CARDIO VASCULAR DISORDERS:

Diseases of heart, blood vessels and blood circulation are known as cardiovascular disorders
(CVDs). Some of these are:
ATHROSCELEROSIS:
Introduction: Atheroscelerosis is the disorder of blood vessels in which arteries losses its
elasticity and becomes harden.
Pathogenesis: The inner wall of arteries become narrow, lose their elasticity due to the
formation of raised patches of fats in their inner lining called atheromatous plaques. In such
condition the flow of blood is disturbed.
Components of Plaques: The raised patches consists of low density lipoprotein (LDL) i.e;
cholesterol and proteins , fibrous tissues decaying muscle cells , clusters of blood , platelets
or calcium.
The causes are:
i. Smoking, hypertension, obesity(fatness)
ii. High cholesterol level in serum.
iii. Severe diabetes and physical inactivity
iv. Anxious and aggressive personality
v. Age factor
Effect:
Until the severe damage to arteries and disturbance in flow of blood there is no significance
and symptoms of atheroscelerosis. It causes pain in the chest, arms or jaws called Angina
Pectoris.
Preventive measures:
By reducing the above causes the prevention of atheroscelerosis can be obtained. Especially
by reducing the use of cholesterol in food.

HYPERTENSION:
Preliminary Statement: when the blood pressure is higher than the normal, it is called
hypertension and person is called hypertensive.
Acute definition: When under resting condition the mean arterial pressure is greater than
110mm Hg, it is considered as High blood pressure and Hypertension.
Manifestation: It takes place when diastolic blood pressure is greater than 90 mm Hg and
systolic blood pressure is greater than 135 mm Hg.
Causes:
The causes of high B.P are:
 i. Use of high amount of salts
ii. Hereditary factor
iii. Smoking
iv. Obesity
v. Disorders of kidney or adrenal glands
Effects:
i. Continuous high B.P damages the lining of blood vessels, so heart muscles become
weak , and its pumping function is affected
ii. It promotes ATEROSCELEROSIS.
iii. Heart may be enlarged.
Inference: it causes stroke or heart attack even no symptoms earlier so it is called “Silent
killer.”

THROMBUS FORMATION:
Definition:
The clotting of blood in the blood vessels is called ‘thrombus formation’.
Cause:
The main cause of thrombus is atherosclerotic plaques i.e; patches of fats in blood vessels.
These patches damage the inner layer endothelium of blood vessels, then in the damaged
regions platelets are deposited, it results in blood clotting.
Pathogenesis: By the continuous process the inner cavity lumen of arteries become narrow
or blocked it reduces or stops the blood supply. Food and O2 cannot be supplied to these
parts properly and function of such affected parts are disturbed.
Clinical Effects: When thrombin occurs in coronary artery (artery of heart), heart attack or
heart stroke occurs and person may die.
Complications: When the blood clot is separated and transferred into the blood stream it is
called Embolus. It can damage any small artery, it may cause Angina or Heart attack.

CORONARY THROMBUS:
Definition: When thrombus i.e; blood clots occur in coronary arteries (arteries which supply
blood to heart muscles) and these arteries are narrowed or blocked it is called coronary
thrombus.
Effect: Due to thrombus O2 is not supplied to any part of the heart, so it becomes dead or
inactive.
Inference: It causes coronary heart disease. By thrombosis heart attack may occur.
Diagnosis: It can be diagnosed by latest technique of ‘Angiography’

MYOCARDIAL INFARCTION:
Definition: When the blood vessels of heart are blocked either by thrombus (clotting of
blood) or embolus, it causes death of a part of heart and continuous
Chest pain, it is called Myocardial Infarction (heart attack).
Pathogenesis: When the coronary arteries of heart are blocked and they do not supply O2 to
the particular organs that heart muscles do not work properly and gradually become dead.
Such muscles of heart are called infracted and the mechanism is known as myocardial
infarction.
Clinical Effects: When the small part of the heart is damaged, the person may recover from
heart attack but when large part is damaged it may cause death of a person.
Precautions:
i. Person should not use fatty food rich in cholesterol.
ii. Body should not be over weight
 iii. B.P should be maintained normal by exercise
iv. Smoking should be avoided
v.
STROKE:
Definition: when any blood vessel in the brain is blocked by clotting (thrombus) or embolus
and there is no proper supply of blood to the brain or sometime there is a leakage of blood
from blood vessels, it causes a Stroke.
Clinical Effects: As a result of stroke the part of the body is paralyzed which are controlled
by damage part. The sensation, movement or function of such parts are badly affected.
When any one cerebral hemisphere is damaged it causes weakness or paralysis of one side of
the body, it is called Hemiplegia.
Causes: Hypertension and atheroscelerosis i.e; formation of fat patches in blood vessels
are main causes for brain stroke.
Preventive measures:
i. Salts should not be used in large quantity.
ii. B.P should keep at normal range by proper diet.
iii. Health should be maintained by exercise. 30 minutes’ walk is a good exercise.

HAEMORRHAGE
Definition: when there is leakage or discharge of blood from blood vessels, it is called
haemorrhage.
Cause: the main cause of haemorrhage is hypertension.
Clinical Effects: When any blood vessel in the brain is ruptured, it causes brain haemorrhage.
The massive accumulation of blood within the tissue is called Haematoma.

HUMAN HEART:
Definition: it is defined as a pumping organ, which is meant to maintain the circulation of
blood in the animal body.
Significance:
The human heart is the most powerful organ in the circulatory system. It starts beating
before the birth and never stops till death.
Location: the heart is the hollow muscular organ present in the thoracic cavity between the
lungs slightly towards left, enclosed within the rib cage.

GROSS STRUCTURE OF HEART:

It shows following structural features:
Protective covering: it is enclosed in a double layered membrane, called pericardium, its
outer layer is the parietal layer and inner is called visceral layer. B/w the two layer is a space
which is filled with a fluid called pericardial fluid which protects the heart from shocks and
jerks.
CHAMBERS OF HEART
There are four chambers of human heart
Right Atrium: it is a small muscular chamber that forms the right and upper part of the heart.
The superior vena cava and interior vena cava open into it.
Two nodes of specialized conduction system is present on the wall of the right atrium SA
node & AV node
Function: it receives deoxygenated blood
Left Atrium: it is also a small chamber that forms left and upper part of the heart
Function :it receives oxygenated blood through two pairs of pulmonary veins and opens into
left ventricle.
Right Ventricle: it is relatively larger chamber that forms border and right lower part of the
heart. Internally it has tough papillary muscles chordae tendinae for attachment which
connect muscles to the tricuspid valves.
Function: It is separated from the left ventricle by interventricular septum. Pulmonary
arteries arise from it.
Left Ventricle: it is the largest chamber of heart. It also has papillary muscles and chordate
tendinae. It has thick muscular walls; its walls are thick than those of the right ventricle.
Function: a big aorta arises from the left ventricle which supplies the blood to the whole
body. The cavity of the left ventricle is narrower than the right ventricle because of more
muscular walls.
SEPTA OF HEART:
 The two atria are separated by a septum which is called inter atrial septum.
 The left and right ventricles are separated from each other by a wall called
intervenetricular septum. It is a specialized conduction system.

VALVES OF HEART:
Tricuspid valve: the right atrium opens into the right ventricle by an aperture called right
atrial ventricular aperture. This aperture is guarded by the tricuspid valves which allow the
blood to flow from R.A to R.V but not in backward direction.
Bicuspid valve: the left atrium opens into left ventricle by an aperture called left atrial
ventricular aperture. It is guarded by a bicuspid valve, but resists blood to flow in backward
direction.
Semilunar valves: their flaps are shaped like half moon, therefore these are called semilunar
valves. These are of two in numbers:
Aortic valve: the semilunar valve b/w the left ventricle and aorta is called aortic valve.
Pulmonary valve: the valve which is located b/w the right ventricle and the pulmonary
artery.

CARDIAC CYCLE:
Definition: the process of working of heart which takes place during the completion of one
heart beat is called cardiac cycle.

Action of heart: the heart works in a systemic way. Its muscles are myogenic i.e; its muscles
contract themselves without any external force.
Working of heart: the period during which chambers of heart contract is called systole and
period during which its chambers show resting or expansion is known as diastole. This
diastole and systole process helps in the working of heart.
Mechanism of Diastole:
When right atrium shows diastole, it receives deoxygenated blood from different parts of the
body through vena cava. Similarly during diastole the L.A receives oxygenated blood from the
lungs.
Mechanism of Systole:
When the atria are full of blood, they contract at the same time, this is called atrial system.
Due to this process the blood are transferring into ventricles. The right ventricle receives
deoxygenated blood and right atrium receives oxygenated blood.
Outflow of blood:
When the ventricles are filled with blood they also contract at the same time, it is called
ventricular systole during which atrio ventricular valves are closed and the aortic, pulmonary
valves are opened. The blood is pumped into respective aorta.
Cardiac output:
The volume of blood which is pumped by the left ventricle into the systemic circuit in one
minute is called Cardiac output.
LYMPHATIC SYSTEM
Definition: a system of blind vessels (lymphatic) that drains lymph from all over the body
back into the blood stream is called Lymphatic System
Distribution: the lymph vascular system starts at capillary bed, where tissue fluid enters the
lymph capillaries, which are closed towards the tissue sinuses. These are thin walled,
microscopic vessels, which form a network in every organ except nervous system.
Components of Lymphatic System:
The system consists of following components:
i. Lymph vessels
ii. Lymph
iii. Lymph nodes
iv. Thymus
v. Spleen
vi. Tonsils
vii. Some of the patches in tissues in vermiform appendix and small intestine.
Lymphatic: the lymph capillaries merge into lymph vessels or lymphatics, which have a large
diameter. These vessels contain smooth muscles in their walls as well as internal valves to
prevent backward flow of lymph.
Lymph: it is defined as a color less body fluid that contains lymphocytes (Agranular WBCs),
small proteins and fats.
Role of Lymph:
i. It is a medium of exchange b/w blood and blood cells.
ii. The lymph has a unidirectional flow from the tissue to the blood and heart.
iii. The lymph play a vital role in the transport of various materials and the immunity
of body.
Lymph Nodes:
At certain points the lymph vessels contain special masses of connective tissues, called lymph
nodes. In these nodes lymphocytes are present. Lymphocytes are the cells of immune
system. Through lymph nodes lymph is filtered. The lymph nodes are of different size, from
microscopic size to one inch.
Lacteals: Within the villi of intestine the lymph vessels are called lacteals. The lymph
circulates through the lymph vessels by the contraction of skeletal muscles in one direction
i.e; to the heart. These vessels form duct which are connected with veins in the lower neck.
Filtration of Lymph:
Many lymphatic vessels carry the lymph into lymphatic node, but from this node a single
large vessel comes out. When lymph is filtered through the lymph nodes the lymphocytes
and microphages present here neutralize it and kill the microorganisms.

FUNCTION OF LYMPHATIC SYSTEM:

1. Drainage system:
The lymphatic system takes part in the returning of water and plasma proteins back to the
blood stream, which has leaked away from the blood. Otherwise death may occur in 24
hours.
2. Defense of body:
Lymphatic system helps to maintain the body resistance. The microorganisms, foreign bodies
and broken cells are removed by macrophages, found in lymphatic nodes.
3. Absorption and delivery of fats:
The lacteals of villi absorb digested fats, which are changed into droplets, after that these fats
are returned back to the blood.
4. Bathing of tissues:
The lymphatic vessels bath the tissues and keep them moist.

EDEMA
Definition: when tissue fluid is not returning into blood by lymphatic system and it is
accumulated in the body tissues and it cause swelling it is called Edema.
Condition: Edema is an abnormal condition caused by lymphatic system when it is not
functioning properly (normally)
Inference: the excess fluid may be in the cells or outside the cells. Edema results in high
blood pressure and kidney failure etc.
Causes:
i. Protein deficiency: it causes edema. When proteins are not used in food the body
consumes its own blood protein so blood cannot absorb tissue fluid. It is accumulated
in the body tissues, it causes edema.
ii. Lymphatic obstruction: lymphatic system becomes fail to return fluid due to any
obstruction, it causes edema.
iii. Filariasis: Filariasis is also a cause of edema. It is a disease due to the nematodes.
iv. Increased permeability of capillaries: due to burns or allergic reaction permeability
of capillaries is increased. It causes edema.

THE IMMUNE SYSTEM:

Definition:
“The system that involves the defence of animals against foreign substances and micro
organisms is referred to as Immune System”
 The main function of immune sys. Is to prevent or limit infections by micro organisms
such as bacteria, viruses, parasites and fungi.
 Immune sys is the collection of cells and proteins that work to protect the body from
potentially harmful, infectious microorganisms.
 It also plays role in the control of cancer, allergy, hypersensitivity and rejection
problems when organs or tissues are transplanted.

IMMUNITY:
“The ability of the body to resist microorganisms their toxins, if any, foreign cells and
abnormal cells of the body is termed as Immunity”
IMMUNOLOGY:
“The study of functioning and disorders of the immune system is termed as “Immunology”

Types of IMMUNE SYSTEM:

The immune system can be divided into two functional divisions:
1-Innate immune system 2-Adapted immune system
INNATE IMMUNE SYSTEM:
the immune system that comprises of natural immunity is referred to as innate immune
system.
It is responsible for innate or natural immunity that is non-specific in nature since it combats
all micro organisms.
Components:
The innate immune system consists of following components:
1-Physical barriers: such as skin, mucous membrane etc.
2-Chemical barriers: against infectious micro organisms e.g. lysozyme, gastric juice etc.
DEFENCE LINES OF IMMUNE SYSTEM:
There are 2 lines of defense of innate immune system:
First Line of Defense;
 Skin and mucous membranes with their secretions act as first line of defense
 The intact skin provides an impenetrable barrier to the vast majority of infectious
agents, most of which can enter only through the mucous membrane , that lines the
digestive, respiratory & urogenital tracts.
 However these areas are protected by the movement of mucous and secretions (e.g.
lysozyme in tears) to destroy many microbes.
 Most of the microorganisms present in food or trapped on swallowed mucous from
the upper respiratory tract are destroyed by the highly acidic gastric juice of stomach.
Second Line of Defense:
 If somehow microorganisms are able to penetrate the outer layer of the skin or the
mucous membrane they encounter the second line of defense offered by the innate
immune system
 It is also non-specific in nature and comprise of;
 1- Phagocytes 2-Antimicrobial proteins 3-Infammatory response
Phagocytes;
They are specific types of WBCs , which can ingest internalize and destroy the particles
including infectious agents. They are of following types;
 Neutrophils:
The short lived phagocytic cells called Neutrophils (polymorph nuclear neutrophils) ingest
bacteria very actively.
 Macrophages:
The monocyte can develop into large, long lived macrophage (big eaters) when they reside in
various tissues of the body. Macrophages not only destroy individual micro organisms but
also play a crucial role in further immune response by presenting parts of that micro
organisms to other cells of the immune system. For this reason they are termed as antigen
presenting cells.
 Natural killer cells;
Another group of WBCs the natural killer cells (NK cells) destroy virally infected own cells of
the body. They also attack abnormal cells (cancerous cells). NK cells do not phagocytize the
target cells. Instead, they bind to their target cell , release some pore forming proteins into
the target cells which eventually cause lysis of target cell. This kind of destroying the target
cells is called ‘cytotoxicity’.
 Antimicrobial Proteins:
Among antimicrobial proteins, important are:
1-lysozyme 2-complement proteins 3-interferons
Lysozyme: is an enzyme present in tear, saliva and mucous secretion . it causes the lysis of
bacteria.
Compliment Proteins: they work in innate as well as adaptive immune system. They directly
cause the lysis of bacteria serve as chemo attractants for macrophages and promote
phagocytosis of bacteria.
Interferons: These are secreted by virally infected cells or some lymphocytes to induce a
state of antiviral resistance in uninfected tissues of the body.
 Inflammation;
Inflammation is the body’s reaction to an injury or by the entry of micro organisms
Inflammatory process has following important characteristics:
 A cascade of chemical reactions takes place during inflammatory response.
 It is characterized by redness, heat, swelling and pain in the injured tissue.
  When injured basophils and mast cells release the substance called histamine
which causes increase in the permeability of the adjacent capillaries local
vasodilation and also makes capillary leaky.
 Due to chemotaxis, phagocytes and macrophages are attracted at the injured
site. The phagocytes literally eat up micro organisms who escape away from
the inflammatory response to infect some large part of the body, trigger fever.
It is usually caused by certain WBCs that release substance called ‘pyrogen’. It
sets the temperature of the body higher than normal.
 Very high fever is dangerous but moderate fever contributes to the defense of
the body .it inhibits the growth of some microorganisms, facilitates
phagocytosis, increase the production of interferon, and may speed up repair
of damage tissues.
ADAPTIVE IMMUNE SYSTEM:
The immune system that comprises the specific immunity against the micro organisms and
the foreign substances is known a adaptive immune system.
Characteristics of Adaptive Immune System;
 The adaptive immune system is extremely complex
 It produces specific immune response against a range of different invading
organisms , toxins, transplanted tissues and tumor cells .
 This is the third line of defence which comes into play simultaneously with the
second line of non- specific defense.
MECHANISM:
 The response of the adaptive immune system is provided chiefly by 2 types of
Lymphocytes called B cells and T cells.
 Depending upon the migration and maturity during the early development in
either bone marrow or thymus, they are designated as B cells or T cells
respectively.
 Although B cells and T cells play quite different roles in the immune system,
yet they share the basic key features of the immune response.
 In order to develop a specific immune response, the immune system must
recognize the invading organisms and foreign proteins from its self tissues.
 A foreign substance that elicits immune response is called ‘antigen’.
 The immune system responds to an antigen by activating lymphocytes and
producing specific, soluble proteins called antibodies.
 The antibody combines with the antigen and helps to eliminate it from the
body.
 The immune system of the vertebrates has virtually unlimited capacity to
generate different antibodies which recognize and bind millions of potential
antigens or foreign molecules.
 The immune system has also the ability to memorize antigens it has
encountered. Thus upon subsequent exposure to the same pathogen, it
responds very quickly and effectively.
TYPES OF ADAPTIVE IMMUNITY:
1-humoral immunity 2-cell- mediated immunity (CMI)
Humoral Immunity:
Immunity provided by the antibodies secreted in the circulatory system by B cell is termed as
humoral Immunity.
Mechanism of Humoral Immunity:
 It has been determined experimentally that each B cell has specific type of
antibodies on its cell surface .this antibody serve as antigenic receptor.
  When an infection occurs, the antibodies borne by a few B cells will bind to
antigens on the surface of microorganisms.
 Antigen-Antibody complex binding causes such B cells to divide rapidly to give
rise enlarged effector cells called Plasma cells.
 Some of the effector cells do not secrete antibody, they become memory
cells.
 Moreover antibodies neutralize the toxins released by bacteria & also cause
agglutination of the microorganisms.
Cell Mediated Immunity:
The immunity mediated by T cells which do not secrete antibodies is known as Cell mediated
immunity.
Characteristics of Cell Mediated Immunity:
1. The cell mediated immunity is contributed by second family of lymphocytes
called T cells.
2. They mediate immunity by killing infected cells
3. This is important against defense against virus as well as some parasites.
4. Several types of T cells contribute to cell mediated immunity:
 Helper T cells (TH)
 Cytotoxic T cells (TC)
 Suppressor T cells (TS)
Mechanism;
 Like B cells, helper T cells and cytotoxic t cells have antigenic receptors called T cell
receptor.
 Helper T cell receptor actually recognize the combination of antigen fragment and
one of the body’s own cell marker called Major Histocompatible Complex (MHC) class
II molecules on the surface of macrophages or B cells.
 Receptors on the surface of cytotoxic T cells recognize a combination of antigenic
fragment & self surface marker molecules called MHC class I.
 After infection is conquered another group of T cells called suppressor T cells seems
to shut off the immune responses in both B cells & cytotoxic T cells.
 During CMI responses, some T cells turn into memory cells to protect the body in case
of re-infection in future.
CYTOKINES (LYMPHOKINES):
Cytokines or the hormones of immune system are protein molecules secreted by the cells of
immune system to regulate the immune response.
Various cytokines including a range of interleukins (IL), interferon, tumor necrosis factors
have been studied.
 Interleukins;
Interleukins are certain type of cytokines, composed mainly of proteins. There are various
types of interleukins IL-1, IL-2, IL-3. They perform functions like activation of T cell or B cell,
stimulation of phagocytosis etc.
 Interferon:
Interferon belonging to the group of proteins produced naturally by body cells in response to
viral infections and other stimuli.
ACTIVE IMMUNITY:
Immunity requires by own immune response is called active immunity.
Types: there are 2 types of active immunity:
1- Natural active 2- Artificial active.
 Natural Active Immunity: it is a consequence of natural infection, it is natural active
immunity.
  Artificial Active Immunity: active immunity can be acquired artificially by vaccination.
In this case it is said to be artificial active immunity.
PASSIVE IMMUNITY:
The immunity that depends upon the antibodies transported from another person or even an
animal is known as passive immunity.
Types: it has 2 main types:
 Natural Passive Immunity:
In this case , the antibodies transferred to one person were derived from another of the
same species.
e.g. a pregnant woman passes some of the antibodies to her fetus through placenta.
 Artificial Passive Immunity;
Passive immunity can also be transferred artificially by introducing antibodies derived from
animals or human being who are already immune to that disease. This is termed as artificial
Passive Immunity.
E.g. Rabies is treated in man by injecting antibodies derived from persons who have been
already vaccinated against rabies.

DIFFERENCES :
DIFFUSION OSMOSIS
1 Diffusion is the net movement of Osmosis is the movement of only solvent or
molecules or atoms from a region of high water molecules across the plasma membrane
concentration to a region of low from the region of its higher concentration to a
concentration. region of its lower concentration.
2 Diffusion can operate in any medium. Osmosis operates in only liquid medium.
3 It does not require any semipermeable A semipermeable membrane is a must for the
membrane. operation of osmosis.
4 It helps in equalizing the concentration of It does not equalize the concentration of solvent
the diffusing substance throughout the on the two sides of the system.
available space.
5 It is not influenced by solute potential. Osmosis is dependent upon the solute potential.
6 Diffusion is applicable to all types of It is applicable to only solvent part of the
substances: solids, liquids, or gases. solution

PROKARYOTIC CELL EUKARYOTIC CELL

1 The size of cell is 0.1-5.0 µm. The size is 5-100 µm.
2 Cell wall, if present, contains a Cell wall, if present, contains cellulose,
mucopeptide or peptidoglycan. peptidoglycan is absent.
3 A typical nucleus is absent. A typical nucleus made of nuclear envelope,
chromatin, nucleoplasm, nuclear matrix and
nucleoli.
4 DNA is naked or without any association DNA is associated with histones.
with histone proteins.
5 Mitochondria, golgi apparatus and Mitochondria, golgi apparatus and endoplasmic
endoplasmic reticulum are absent. reticulum are present.
6 Microtubules and microfilaments are rare. They are usually present.
7 DNA is generally circular. DNA is commonly linear.

CELL WALL CELL MEMBRANE

1 It is a rigid, thick structure and visible in It is delicate, thin structure visible only in
light microscope. electron microscope.
2 It the outermost layer in pant cell and It is the outermost layer in animal cell and occurs
occurs as a protective covering as a semi permeable covering surrounding the
surrounding the plasma membrane. protoplasm.
3 Cell wall is made up of cellulose in plant Plasma membrane is made up of lipids, proteins
cell wall. and small amount of carbohydrates. `
Cell wall is made up of peptidoglycan in
bacterium.
Cell wall is made up of chitin in fungi.
4 It is completely permeable. It is selectively permeable or semipermeable
allowing only certain molecules to pass through.
5 It occurs in plant cell, bacterium and It occurs in all cells.
fungus.
6 It is metabolically inactive and non-living. It is metabolically active and living.
7 It determines the cell shape and offers It protects the protoplasm and maintains a
protection. constant interval environment to the
protoplasm.

RACEMOSE INFLORESCENCE CYMOSE INFLORESCENCE

1 The growing point seldom ends in flower. The growing point always forms a flower.
2 The floral axis or peduncle is monopodial. The floral axis is sympodial or multipodial.
3 The formation of flowers is indefinite or The definite or restricted number of flowers are
unrestricted. formed.
4 The arrangement of flower is acropetal. The arrangement of flower is basipetal which is
clearly visible in biparous and multiparous
cymes.
5 The arrangement of flowers in group is The arrangement of flowers in a cyme head and
centripetal, that is, the younger flowers are other type of grouping is centrifugal, that is, the
towards the centre and the older towards older flowers are towards the centre and the
the outside. younger towards the periphery.

PHOTOSYNTHESIS RESPIRATION
1 It is a anabolic process that results in It is a catabolic process results in bond
manufacturing of food. destruction
2 Takes place only in chlorophyllous cells Takes place in all cells
3 Energy is stored in this process so it is an Energy is released in the process so it is an
endothermic process exothermic process.
4 Photophosphyration occurs Oxidative phosphorylation occurs.
5 Light energy is converted into potential During this process, potential energy is
energy converted into kinetic energy
6 Dry weight of plant increases Dry weight of plant decreases
7 Carbon dioxide and water are used while Oxygen is utilized and carbon dioxide and water
oxygen is evolved are formed
6CO2 +12H2O  C6H12O6 + 6H2O +6O2 C6H12O6 + 6O2 6 CO2 + 6 H2O+ energy

ASCENT OF SAP TRANSLOCATION OF FOOD

1 The ascent of sap in the xylem tissue of Translocation is the movement of organic food
plants is the upward movement of water such sucrose and amino acids in phloem; from
and minerals from the root to the crown regions of production to regions of storage.

PHOTOPHOSPHORYLATION OXIDATIVE PHOSPHORYLATION

1 Occurs during photosynthesis. Occurs during respiration.
2 Occurs inside chloroplast Occurs inside mitochondria
3 Pigment systems ( PS I and PS II) are Pigment systems are not involved.
involved
4 Molecular oxygen is not required Molecular oxygen is required for terminal
oxidation
5 The ATP molecules produced is used to fix The ATP molecules produced are released into
CO2 to carbohydrates in dark reaction. the cytoplasm and this energy molecules are
used to carry out various metabolic reactions of
the cell.

LIGHT REACTION DARK REACTION

1 Occur in : grana of the chloroplast Occurs in : stoma of chloroplast
2 It is a light dependent process and No photosystem is required.
involves
two photosystems : PS1 and PS2
3 Photolysis of water takes place and CO2 is absorbed and photolysis of water
oxygen is liberated. does not takes place.
4 ATP and NADPH is produced and they are Glucose is produced. Reduced NADP is
used to drive the reaction. oxidized.

VESSELS TRACHEIDS
1 Vessels are main conducting elements of Main conducting system of pteridophtes
angiosperm and gymnosperm
2 Vessels originate from longitudinal file of Tracheids originate from single cells
cells
3 Vessels have a comparatively wider They have comparatively narrow diameter
diameter
4 They are perforated cells They are imperforated cells
5 They have small pits which are larger in They have larger pits which are less in
number number
6 They are more efficient in water Less efficient in water conduction
conduction due to the presence of
perforations
7 Walls are more thickened with narrow Walls are less thickened with large lumen
lumen

ALGAE FUNGI
1 They are mostly aquatic Mostly terrestrial
2 Algae possess the green coloring Fungi never possess chlorophyll
pigmented known as chlorophyll
3 Algae are autotrophs Fungi are heterotrophs
4 They cannot live without light as light is Fungi can live in light as well as in darkness
necessary for the preparation of their
food
5 Algal cell wall is mainly composed of They are mostly composed of chitin
carbohydrate cellulose
Food reserve is frequently in the form of Reserved food is accumulated in the form
starch of glycogen and oil globules.

FACILITATED DIFFUSION ACTIVE TRANSPORT

1 It does not need energy It needs energy
2 Facilitated diffusion (also known as It is a process by which molecules are
facilitated transport or passive-mediated enabled to pass across a membrane from a
transport) is the process of spontaneous region in which they are in a low
passive transport (as opposed to active concentration to one of high concentration
transport) of molecules or ions across a
biological membrane via specific trans
membrane integral proteins.
3 Not assisted by carrier proteins Assisted by carrier proteins

AEROBIC RESPIRATION ANAEROBIC RESPIRATION

1 Common in all higher plants and animals Very rare in higher plants and animals
2 Occurs in presence of oxygen Occurs in absence of oxygen
3 The process in non-toxic The process is often toxic to both plants
and animals
4 End products are CO2 and H20 End products are ethanol and CO2
5 Energy is released in greater amounts in Energy is released in lesser amounts in the
the form ATP – 36 ATP molecules form of ATP – 2ATP molecules.

HIBERNATION AESTIVATION
1 It is winter sleep in which animal passes It is a summer place
the winter period in dormant condition
2 Animal rests in a dry place Animal rets in cool or shady place
3 It is of longer duration It lasts for hot dry day time as nights are
cooler
4 Both cold-blooded and warm-blooded Invertebrate and vertebrate animals are
animals may exhibit hibernation known to enter this state to avoid damage
from high temperatures and the risk of
desiccation
5 Insects, small birds and mammals Aestivators are snails, earthworm, bees ,
hibernate regularly each year. salamander etc

RADIAL SYMMETRY BILATERAL SYMMETRY

 A basic body plan in which the organism can a basic body plan in which the left and right s
1 be divided into similar halvesby passing a pla ides of the organism can bedivided into appr
ne at any angle along a central axis oximate mirror images of each other along t
he midline.

2 Characteristics of sessile and bottom- Bilateral symmetry is a characteristic of animals

dwelling animals. that are capable of moving freely through their
environments.
3 The body plans of echinoderms, ctenophore Humans, cats, ants, butterflies shows
s, bilateral symmetry.
cnidarians, and many sponges and sea anem
ones show radial symmetr

COELOM PSEUDOCOELOM
1 Coelom is derived from two different ways Pseudocoelom is derived from the
such as the splitting of the mesoderm and blastocoel of the embryo
out pocketing of archenteron fusing
together to form the coelom.
2 In coelomates, organs are suspended in a In pseudocoelomates, organs are held
well-organized manner loosely and are not well organized as
coelomates.
3 Coelom allows the formation of an efficient Pseudocoelom does not aid in the formation
circulatory system of a circulatory system.
4 In coelom, nutrients circulate through the Psudocoelom, nutrients circulate through
blood system. diffusion and osmosis
5 Coelom is segmented Pseudocoelom is not segmented
6 They have muscles and supporting Pseudocoelom lacks muscles or supporting
mesentries mesenteries,

ACRANIATA CRANIATA
1 It is also known as protochordata. It is also known as vertebrata.
2 Cranium and jaws are absent. Cranium and jaws are present.
3 Subphyla which is grouped under Two divisions- agnatha and gnathostomata
acraniata are hemichordate, Urochordata are classified under craniata.
and cephalochordate.
4 Examples- Herdmania, Amphioxus Examples- Petromyzon, frog, fish

INSPIRATION EXPIRATION
1 It is an active process. It is a passive process.
2 Contraction of external intercostal Relaxation of external intercostal muscles
muscles and relaxation of internal and contraction of internal intercostal
intercostal muscles occur. muscles occur.
3 Ribcage moves forward and outward. Ribcage moves downward and inward.
4 Diaphragm contracts and becomes Diaphragm relaxes and become original
flattened. dome shaped.
5 Volume of thoracic cavity increases. Volume of thoracic cavity decreases.
6 Air pressure in lungs is less than Air pressure in lungs is higher than
atmospheric pressure. atmospheric pressure.
7 Intake of air into lungs. Expulsion of air out from lungs.
DIPLOBLASTIC ORGANISMS TRIPLOBLASTIC ORGANISMS
1 Body wall develops from two embryonic Body develops from three germ layers-
germ layers-ectoderm and endoderm ectoderm, mesoderm and mesoderm.
and persists as such in adult.
2 Non-cellular, gelatinous mesoglea is Mesoglea is absent and mesoderm is
present in between ectoderm and present.
endoderm.
3 Coelom is absent. Coelom is present.
4 Example- Hydra (coelenterates), sponges Example- Platyhelminthes, annelids,
(Porifera). arthropods, mollusks, echinoderms and
chordates.

NUCLEOSIDE NUCLEOTIDE
1 A nucleoside consists of a nitrogenous A nucleotide consists of a nitrogenous
base covalently attached to a sugar base, a sugar (ribose or deoxyribose) and
(ribose or deoxyribose) but without the one to three phosphate groups.
phosphate group.
2 Examples of nucleosides include cytidine, Nucleotides follow the same names as
uridine, adenosine, guanosine, thymidine nucleosides, but with the indication of
and inosine. phosphate groups. For example, 5'-uridine
monophosphate.

OPEN TYPE CIRCULATORY SYSTEM CLOSE TYPE CIRCULATORY SYSTEM

1 Blood flows through open spaces called Blood flows through close vessels.
lucanae and sinuses.
2 Blood flows at very slow velocity. Blood flows at very high velocity.
3 Body cavity (haemocoel) is filled with Haemocoel is absent.
blood.
4 Internal organs are bathed in blood. Internal organs are not in direct contact
with blood.
5 Supply and elimination of material is very Supply and elimination of material is very
low. rapid.
6 Exchange of material takes place Exchange of materials between blood and
between blood and sinus. tissues takes place through the capillaries.
7 Blood flow cannot be regulated. Blood flow can be regulated.

DNA RNA
 DNA is double stranded specially in  RNA is single stranded.
eukaryotes
 DNA contains deoxyribose sugar  RNA contains ribose sugar
  DNA consist of cytosine & thymine  RNA contains cytosine & uracil
(pyrimidine bases) (pyrimidine) bases. There is no
thymine.

 DNA is a hereditary material  RNA is associated with protein

synthesis
 DNA is found in the nucleus (in  RNA is found in cytoplasm.
eukaryotes)

HOLOENZYMES APOENZYMES
1. Conjugated enzymes are called 1. Protein part of an enzyme is called
holoenzymes. apoenzyme.
2. They are the enzymes showing complete 2. It is unable to show complete activity.
activity.
3. Holoenzymes consist of apoenzyme and 3. Apoenzymes comprises only of protein.
prosthetic group.

ACTIVATORS INHIBITORS
1.Substances which increase the activity of 1.Substances which decrease the activity of
enzyme are called activators. enzyme are called inhibitors
2.They are mainly inorganic substances 2.They are of 2 types: Competitive & non-
competitive inhibitors
3.e.g:Zn++ for carbonic anhydrase
Mg ++ for phosphatase

ENDOENZYMES EXOENZYMES
1. The enzymes which act within the cell are 1. The enzymes which act outside the cell are
called endoenzymes. called exoenzymes.
2. They are also called as intracellular 2. They are also called as extracellular enzymes.
enzymes.
3. A part from digestion , they also help in They are hydrolytic i.e they help in digestion.
other metabolic function like respiration.
e.g hexokinese , transketolase e.g pepsin , amylase

DIFFERENCE BETWEEN:
LYSOSOME VACOULE
  They are spherical in shape.  Vacuoles have irregular
body shape.

 They are formed by golgi  They are formed at the time

bodies. of need.
 They usually contain  They contain hydrolytic
digestive enzymes. enzymes.
 They are membrane  It is surrounded by a
bounded organelles having membrane called tonoplast.
single membrane.
 They are referred as suicide  They play an important role
sacs. in plant defence.
 The membrane of  The tonoplast of vacuole is
lysosomes is permeable for much more permeable than
substances. lysosome.

LIGHT MICROSCOPE ELECTRON MICROSCOPE

ADVANTAGES: ADVANTAGES:
1.It is cheap to purchase & operate. 1.It is costly to purchase & operate.
2.It is small in size & portable.it can be easily 2.It is large, can’t be shifted easily. For its
taken & used anywhere. operation a separate room is required.
3.It can’t be affected by magnetic field. 3.It is affected by magnetic field.
4.Preparation of material is fast, easy, simple & 4.Preparation of material is lenghty, more
cheap. difficult & expensive.
5.During preparation the material is rarely 5.During preparation there are more chances
damaged. that material can be damaged.
DISADVANTAGES: DISADVANTAGES:
1.Its magnification power is limited upto 2000X 1.Its magnifying power is very large over
500000X
2.The object can’t be studied in depth 2.The object can be studied in depth

CELL WALL CELL MEMBRANE

1.The outer most part of plant cell which is 1.The outer most part of animal cell which
made up of cellulose is known as cell wall separates the cytoplasm from external
environment is known as cell membrane
2.protoplasm is present in cell wall 2.Cytoplasm is present in cell membrane
3.Cellulose or polysaccharides is the main 3.Phospholipids are main constituents of cell
constituent of cell wall membrane
4.They are only present in plant cell 4.They are present both in animal & plant cell
5.It gives proper shape to cell and acts as 5.It serves as envelope membrane and gives
permeable structure proper shape to cell

DIFFERENCE BETWEEN PROARYOTES & EUKARYOTES:

PROKARYOTES EUKARYOTES
1.The organisms which do not contain 1.The organisms having a true nucleus in their
membrane nucleus in their cells are cells are eukaryotes
prokaryotes
2.Membrane bound organelles such as 2.Membrane bound organelles are present
mitochondria, lysosomes, golgi bodies,
 endoplasmic reticulum and chloroplast are
absent
3.Genetic material is scattered in the cytoplasm 3.Genetic material is within the nucleus
4.These are usually enclosed in a rigid cell wall 4.They contain both cell wall & cell membrane
5.Examples of prokaryotes are blue green algae 5.Examples belongs to kingdom protista, fungi,
& bacteria plantae & animalia

 Bryophytes are non-vascular plant. They  Tracheophytes are vascular plants. They
do not have xylem and phloem. have xylem and phloem.

 They do not have true root, stem and  They have true roots, stem and leaves.
leaves.
 They grow in cool, moist and shady  They grow in every types of condition.
places.
 The main or dominant generation is  The main or dominant generation is
gametophyte (i.e. haploid (n)) while sporophyte (i.e. diploid (2n)) while
sporophyte (i.e. diploid (2n)) is totally gametophyte (i.e. haploid (n)) is
dependent on gametophyte. dependent on sporophyte.
 Bryophytes need water for fertilization.  Tracheophytes do not need water for
fertilization.
 E.g. Funaria, Marchantia.  E.g. Fern, Brassica, Pinus etc.

ANGIOSPERM GYMNOSPERM
 Angiosperms are found almost in  Gymnosperms usually grow at high
every types of environment. altitude and colder regions
 They may be herbs, shrubs and  They are usually trees and few are
trees. shrubs.
 The seeds of angiosperms are  The seeds of gymnosperms are not
enclosed in fruits. closed in fruits.
 Pollination is usually brought about  Pollination is usually carried out
by wind, water, insects and animals. through wind.
 Leaves of angiosperms are usually  Leaves of gymnosperms are usually
broad and flat. thin, long and needle like.
 Their leaves fall in autumn.  They are evergreen plants therefore
their leaves do not fall in autumn.
 Reproductive organs are called  Reproductive organs are called
flowers. cones.
 Double fertilization takes place.  Double fertilization does not take
place.

BRYOPHYTA
DEFINITION:
DIPLOBLASTIC ORGANIZATION TRIPLOBLASTIC ORGANIZATION
1. This type of organisms has two layers outer 1. This type of organization has three layers
ectoderm and inner endoderm. outer ectoderm, middle mesoderm and inner
endoderm.
2. Between two layers gelatinous layer is 2. Between two layers mesoderm layer is
present called mesoglea. present.
3. This is found in less developed organisms e.g. 3.This is found in developed organisms e.g.
Phylum Cnidarian. Chordates, Arthropod etc.
1. They have elongated or spindle shaped body. 1.They are of different shapes, such as flat, oval
etc.
2. Their endoskeleton is composed of cartilage 2. Their endoskeleton is bony made of
and chondrioytes. osteocytes.
3. Their skin contain sharp enamel coated 3. Exoskeleton is made up of thin bony plates
denticles called placoid scales, these scales which are called cycloid scales.
made their endoskeleton.
4. They all are marine fishes. 4. They are marine as well as fresh water.

5. They are usually not edible. 5. They are mostly edible.

6. The gills are exposed i.e., not covered by any 6. The gills are covered by an outer thick
covering or operculum e.g. sharks, skates, rays. covering operculum. E.g. sea horse, globefish,
pomfret.

SUB CLASS RATITAE SUB CLASS CARINATAE

1. These birds cannot fly because they are 1. These birds can fly and are light weight.
heavy weight.
2. Their wings are vestigial or rudimentary. 2. Their wings are highly developed and
feathers of their wings have an interlocking
mechanism.
3. They have flat sternum without keel. 3. Their sternum is provided with a crest like
keel.
4. Their flight muscles are poorly developed. 4. They have highly developed pectoral flight
muscles.
5. The distribution of ratitae is restricted e.g. 5They are distributed all around the world e.g.
ostrich, kiwi. peacock, horibora.

RESPIRATION PHOTOSYNTHESIS

 It is biochemically a catabolic process.  It is anabolic process

 Carbohydrates are broken down.  Carbohydrates are manufactured.
 The reactants are carbohydrates and O2.  The reactants are CO2 and H2O.
 The end products are CO2 and H2O.  The end products are carbohydrates and O2.
 Oxygen is taken in and CO2 is given out.  CO2 is taken in and Oxygen is given out.
 The dry weight of plant body decreases.  The dry weight increases.
 It takes place in all living cells.  It takes place only in chlorophyllous cells.
 It takes place 24 hours, i-e day & night.  It takes place day time only.
 It takes place in light as well as in darkness.  It takes place only in light.
 The amount of CO2 released is proportional to  The amount of CO2 taken in is proportional to the
the amount of O2 inhaled. amount of O2 released.
 It is an energy releasing process.  It is an energy consuming process.
 Oxidation of carbohydrate into CO2 and reduction  Oxidation of H2O into O2 and reduction of carbon
of O2 into H2O takes place. into carbohydrates takes place.
 Summary chemical equation  Summary chemical equation
6O2 + C6 H12 O6 → 6CO2 + 6H2O + 673 Kcal 6CO2 +6H2O + 673 Kcal → C6 H12 O6 + 6O2