Prof. Muhammad Saleem Mughal
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UNIT – 1
THE BIOLOGY
IMPORTANT STUDY POINTS:
1.1 Biology and its major fields
❖ Kingdom Prokaryotae (Monera) includes all the prokaryotes.
❖ Kingdom Protoctista (protista) includes all the acellular (unicellular) as well as multicellular,
eukaryotic organisms, which are no longer classified as animals, plants or fungi.
❖ Kingdom Fungi includes non-chlorophyllus, multi-cellular, organisms having chitinous cell
wall and coenocytic (multi-nucleated) body called mycelium.
❖ Kingdom plantae includes all the chlorophyllus, multi-cellular, eukaryotic living organisms,
having cell wall (cellulose).
❖ Kingdom Animalia includes all the non-chlorophyllus, multi-cellular, eukaryotic organisms
having no cell wall.
❖ Scientists have discovered and named more than one and a half million species of living
organisms.
❖ Modern biology not only concerns with the recognition and classification of these species but
also deals with their vital structural and functional aspects.
❖ Molecular biology deals with the structure and function of the molecules that form structure of
cell and organelles that take part in the biological processes of living organisms (Nucleic acid,
Protein molecules).
❖ Micro-biology deals with the study of micro organisms (viruses, bacteria, protozoan etc).
❖ Environment biology deals with the study of environment and its effects on organism.
❖ Marine biology deals with the study of organisms inhabiting the sea and ocean and the physical
and chemical characteristics of their environment.
❖ Fresh water biology deals with the life dwelling in the fresh waters, physical and chemical
characteristics of fresh water bodies affecting it.
❖ Parasitology deals with the study of parasitic organisms, their life cycles, mode of transmission
and interaction with their hosts.
❖ Human biology deals with all biological aspects of man regarding evolution anatomy,
physiology, health, inheritance etc.
❖ Social biology is concerned with social interactions within a population of a given animal
species.
❖ Biotechnology deals with the use of the data and techniques of engineering and technology for
the study and solution of problems concerning living organisms particularly the human beings
1.2
Levels of biological organization.
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Life is built on a chemical foundation.
An atom is smallest possible unit of an element.
An atom is composed of subatomic particles.
Atoms may combine in specific ways to form molecules.
Extremely large and complex molecules are manufactured by living matter (within the bodies
of living organisms).
Molecules of different elements comprise a compound.
The life emerges on the level of the cell.
A cell is the smallest unit of living organisms.
Genes are functional units of DNA.
The genes provide necessary information needed to control the life of the cell.
Organelles function as chemical factories and use the information in the genes to keep the cell
alive.
Cells of similar type form tissues which perform a particular function.
Various tissue types combine to make up an organ.
Several organs that collectively perform a single function form an organ system.
Different organ systems functioning in a high advanced co-ordination and co-operation make
up an individual whole organism.
Prof. Muhammad Saleem Mughal
❖ Members of the same species living in close association in a given area are considered as
population.
❖ Population of several species living and interacting in the same area forms a community.
❖ A community with its environment, including land, water and atmosphere, constitutes an
ecosystem.
❖ The entire surface region of earth inhabited by living things is called biosphere.
1.3 Living world in space and time
❖ Life arose in this world almost two and half billion years ago.
❖ First living forms were of simple acellular organization.
❖ Majority of living organisms occur as free-living forms but those who failed to do so have
developed ways of interactive life.
❖ Fossils of different groups of organism have different age supporting the concept that different
organism arose in different geological times.
❖ A common origin of species is called phyletic lineage. It is unbroken series of species arranged
in ancestor to decedents sequence with rest of the groups evolved from one that immediately
proceeded.
1.4 Biological Methods
❖ One the base of facts, a scientist formulates a tentative statement called hypothesis.
❖ In Inductive reasoning, a scientist uses isolated facts to reach a general idea that explains a
phenomenon.
❖ Deductive reasoning involves an “if – then” statement.
❖ On the bases of true hypothesis, a theory is put forward which is fairly but not absolutely reliable
statement.
1.5 Applications of biology for the welfare of mankind
❖ The rates of infant mortality and morbidity have been greatly reduced by immunization by
vaccination. It was first introduced by Edward Jenner in 1975.
❖ Antibiotics are substances which in low concentration inhibit the growth of micro-organisms.
❖ The first antibiotic to be discovered was pencillin.
❖ The credit for the discovery, isolation and large scale production goes to Fleming Florey and
Chain.
❖ Radioactive rays (X-rays), has been used in medical sciences for the diagnosis and treatment of
human diseases.
❖ Hydroponics (water culture) is the science of growing terrestrial plants in aerated solution.
❖ Cloning is production of duplicate copies of genetic material; cells or entire multi-cellular living
organisms.
❖ Dolly, the sheep was first highly successful (artificial) clone from a somatic cell.
❖ Pollution has been the biggest problem of man for many years.
❖ Many of the waste products of modern technology are toxic.
❖ Man’s activities mainly deforestation and industrialization have disturbed the balance of nature
with catastrophic results. The use of natural processes to combat pathogens is very helpful.
1.6 Concept of biological control and integrated disease management
❖ Biological pest control involves exposing them to predators and parasites.
❖ Growing plants in climates that are unsuitable for the pathogen can control plant diseases.
❖ Through crop rotation, the chances or establishing particular weed parasites affecting that crop
is reduced.
❖ Soil fertility can be increased by introducing a crop of leguminous family which has nitrogen
fixing bacteria in their root nodules.
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Prof. Muhammad Saleem Mughal
UNIT - 2
KEY POINTS
BIOLOGICAL MOLECULES
 The branch of biology which explains the biochemical basis of life is called biochemistry.
 Living cell contains a living material called protoplasm.
WATER
 Chemically protoplasm contains 70 to 90% of H 2 O.
 If the water is evaporated the remaining mass is called dry weight of the cell.
 Only six elements carbon, hydrogen, nitrogen, oxygen, phosphorus and Sulphur make most
(about 98%) of the biochemical.
 Life activities occur in the cell due to the presence of water.
 Water is a polar molecule.
 A buffer helps to prevent changes in the pH of a solution when an acid or an alkali is added.
ORAGANIC MOLECULES
 Organic molecules containing carbon as a basic element is bounded covalently with Hydrogen
atom.
 Macromolecules are composed of large numbers of low molecular weight building blocks or
subunits called monomers.
 The macromeres are also called polymers.
 Macromolecules can be divided into four major categories, proteins, polysaccharides, lipids
and nucleic acid.
 Proteins are composed of subunits called amino acid.
 Polysaccharides are composed of monosaccharide, fatty acid and glycerol are the subunit of
fats and the nucleotides are the subunits of nucleic acid.
 Two monomers join together when a hydroxyl (-OH) group is removed from one monomer and
a hydrogen (-H) is removed from other.
 The joining of two monomers is called condensation.
 This type of condensation is called dehydration syntheses because water is removed
(dehydration) and a bond is made (synthesis).
 A process during which polymers are broken down into their subunits (monomers) by the
addition of H 2 O is called hydrolysis.
CARBON
 Chemistry of living world is the chemistry of carbon.
 Carbon can form four covalent bonds with other carbon atoms.
 Functional groups are particular group of atoms that behave as a unit and gives organic
molecules their physicochemical properties and solubility in aqueous solution.
 Easter bond is formed between carboxylic acid and alcohol.
 Amide bond is formed between carboxylic acid and amine.
PROTEINS
 Proteins constitute more than 50% of dry weight of cell.
 Proteins are the complex organic compounds having C, H, O and N as elements but sometimes
they contain P and S also.
 Proteins are macromolecules or polymers of amino acid.
 These amino acids are linked together by specialized bond or linkage called peptide linkage.
 There are twenty basic amino acids.
 Amino acids are organic compounds which contain at least one basic amino group (-NH 2 ) and
one acidic carboxylic group (-COOH) bounded to the same carbon atom called  -carbon.
 There are four basic structural levels of proteins.
CARBOHYDRATES
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Prof. Muhammad Saleem Mughal
 Carbohydrate is a group of organic compounds having carbon, oxygen and hydrogen.
 Carbohydrates are found about 1% by weight and generally called sugar or saccharide due to
their sweet taste except polysaccharide.
 Monosaccharides are also called simple sugars because they can not hydrolyzed further into
simpler sugars.
 All monosaccharide white crystalline solids with sweet taste and soluble in water.
 The carbohydrates molecule which yield 2 to 10 monosaccharide molecules on hydrolysis are
oligosaccharide.
 Polysaccharides are of high molecular weight carbohydrates, which on hydrolysis yield mainly
monosaccharide or products related to monosaccharide.
 Starch is the most important reserve food material of higher plants.
 Cellulose is the main constituent of plant cell wall and most abundant carbohydrate in nature.
 Glycogen found mainly in bacteria, fungi, liver and muscle tissues of animals. It is commonly
known as animal starch.
 Carbohydrates are the potential source of energy.
LIPIDS
 Lipids are the compounds containing carbon, hydrogen and oxygen like carbohydrate but
contain much lesser ration of oxygen than carbohydrates.
 When compared an equal amount of acylglycerol contains over twice the energy content than
carbohydrate.
 Acylglycerol consists of a glycerol molecule linked to three fatty acids. This condensed
molecule is also called a Triacylglycerol (Triglyceride).
 Waxes are simple lipids having one molecule of fatty acid forming ester bond with one
molecule of long chain alcohol.
 Phospholipids are replaced by phosphate group.
 Terpenoid is large and important class of lipids, built up of isoprenoid (C 5 H 8 ) units.
 Terpenes group of lipid is based only one isoprenoid (C 5 H 8 ) .
 Steroids consist of three 6-membered carbon rings and one 5-membered carbon ring (D).
 Carotenoids consist of fatty acids like carbon chain which are conjugated by double bonds and
carrying 6-members carbon ring at each end.
NUCLEIC ACIDS
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Friendrish Miesche, isolated substance from the neclie of pus cells and named it was ‘nuclein’.
Nuclein had acidic properties and hence it was renamed as nucleic acid.
The nucleic acids are long chain of polynucleotide.
There are two kinds of nucleic acids, deoxyribonucleic acid (DNA) ribonucleic acid (RNA).
DNA is found mainly in the chromatic of the cell nucleus whereas most of the RNA (90%) is
present in the cell cytoplasm and a little (10%) in the nucleolous.
Nucleotide is a molecule which consists of following three parts. (i) Pentose sugar (5 carbon),
(ii) Phosphoric acid (H 3 PO 4 ) and (iii) A nitrogenous base.
Ribose is found in RNA nucleotides while deoxyribose sugar is found in DNA nucleotides.
Phosphoric acid is common in all nucleotides.
There are two basic types of nitrogeno7us bases i.e. Purine, Pyrimidine, Purine includes two
nitrogenous bases named Adenine (A) and Guanine (G) while pyrimidine includes three
nitrogenous bases cytosine (C), thymine (T) and uracil (U).
The nitrogenous base combines with pentose sugar at its first carbon to form a nucleoside.
The phosphoric acid combines with 5th carbon of pentose sugar forms a nucleotide.
ATP (Adenosine phosphate is the most important among these nucleotide.
ATP consists of adenosine (Adenine and ribose sugar and three phosphate; among them two
are energy rich phosphate bond).
During conversion of ATP into ADP the free energy releases which is considerable large i.e.
31.81 Kg or 7.3 K. Cal/mol energy.
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Prof. Muhammad Saleem Mughal
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Two nucleotides are covalently bounded together to form dinucleotide.
DNA is a co-enzyme.
Hershey and chase thus experimentally confirmed that DNA must be the genetic material.
Genetic information flows in a cell from DNA to mRNA than to cytoplasm in a two step process
for the synthesis of protein.
 Transcription in a specific segment of DNA is copied into RNA.
 Transfer RNA (tRNA) and ribosomal RNA (rRNA) translate the information of messenger
RNA into the specific sequence of amino acids which help in synthesis of proteins.
CONJUGATED MOLECULES
 Glycolipids are conjugated lipids containing fatty acids with carbohydrates and also contain
nitrogenous compound.
 Glycoproteins are formed when a molecule of carbohydrate combine with a protein molecules.
 Nucleoproteins give rise to simple proteins and nucleic acids.
 Lipoproteins are conjugates of lipids and proteins.
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Prof. Muhammad Saleem Mughal
UNIT - 3
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ENZYMES
KEY POINTS
 Biocatalysts are called enzymes.
 The term ‘enzyme’ was coined by Friedrich Wilhelm Kuhne (1878).
 Enzymes may be defined as organic substances capable of catalyzing specific chemical reaction
in the living system.
 Thomas Cech and Sidney Altaman discovered that certain molecules of ribonucleic acid also
function as enzymes.
 Generally enzymes are proteinaceous in nature.
ENERGY OF ACTIVATION
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Enzymes lower down the activation energy of reaction.
The enzymes which act within the cell are referred as intra-cellular enzyme or endoenzymes.
The other ones are called extra-cellular enzymes or exoenzymes.
Enzymes are specific in their nature.
Enzyme molecules are much greater in size than the substrates.
Each enzyme has a dimple or groove of a specific shape called the active site, into which
substrate can fit.
 Fischer (1898) proposed a ‘key-lock’ theory which was later improved by Paul Filder and D.D.
Woods.
 Koshland (1959) proposed induce Fit Model.
TYPES OF ENZYMES
 If an enzyme consists only of protein it is called simple enzyme and if it contains another protein
it is called conjugated enzymes.
 Conjugated enzyme showing complete activity can be called holoenzyme.
 It contains two parts the protein part of enzyme is called apoenzyme and the non protein part is
called prosthetic group.
 Holoenzymes are of two types.
 The holoenzymes in which prosthetic group is an organic ion (co-factor).
 The holoenzymes in which prosthetic group is an organic compound (co-enzyme) although
inorganic ions may also present in it.
FACTORS AFFECTING ENZYME ACTIVITY
 The factors which affect the enzyme activity; concentration of substrate, Temperature, pH, Coenzymes activators and inhibitors, water and radiation.
 Inorganic substances which increase the activity of an enzyme are called activators.
 Substances which decrease the activity of enzyme are called inhibitors.
 Inhibitors are of two types; competitive and non-competitive inhibitors.
 Competitive inhibitors resemble the normal substrate molecules and compete for admission into
the active site.
 Non-competitive inhibitors obstruct enzymatic reactions by binding to a part of the enzyme
away from the active site. This interaction causes enzyme molecule to change it shape rendering
the active site unreceptive to substrate or leaving.
 This other binding site is called allosteric site.
 When the production is abundance it binds competitively with its enzymes active site.
 Most enzymes pathways are also regulated by feed-back inhibition.
Prof. Muhammad Saleem Mughal
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UNIT - 4
CELL AS BASIC UNIT OF LIFE
THE CELL
 The term cell (Greek, Kytos-cell; La; Cella-hollow space) was first used by Robert Hooke
(1665) to describe his investigations on the structure of cork.
 Robert Brown (1831) discovered a spherical body the nucleus, in the cells of orchids.
 Schwann observed that the nucleus was surrounded by a fluid in the cell. He described the “Cell
as a structure which consists of a nucleus surrounded by a semifluid substance enclosed by a
membrane”.
 The cell theory state that “All organism are composed of one or more cells and the cell is the
structural unit of life.
 Now, a cell is defined, “cell is the structural and functional unit of living organisms or cell is
the basic unit of life”.
MICROSCOPY
 According to the source of light following types of microscopes can be recognized Light
microscope, X-ray microscope and Electron microscope.
 Magnification is a means of increasing the apparent size of the object.
 Resolution or more correctly the minimum resolved distance is the capacity to separate adjacent
from or object.
 A very high magnification can be obtained by ordinary light microscope but their resolving
power is limited. It is about 500 times better than unaided human eye.
 Electron beams have much shorter wavelength than visible light, electron microscopes are
capable of resolving objects about 10,000 times better than unaided human eye.
 Isolation of cellular components to determine their chemical compositions is called cell
fractionation.
EUKARYOTES AND PROKARYOTES
 Eukaryotes are those organisms which have a true nucleus (membrane bound) in their cells.
 They also contain a variety of membrane bound organelles.
 Prokaryotes are those organisms which do not contain a true (membrane bound) nucleus in their
cells; their nucleic material is usually coiled and concentrated in a region of the cell called
nucleoid. They also do not contain other membrane bounded structures.
 They only contain mesosomes, which are simple infoldings of the plasma membrane
responsible for respiration photosynthesis, nitrogen fixation etc.
EUKARYOTIC CELL
 The typical Eukaryotic cells contain three major parts but 4 th compound i.e. cell wall is only
found in plant cells.
PLASMA MEMBRANE
 Plasma membrane allows the cell to take up and retain substances while excluding others.
 All biological membranes have the same basic molecular organization. They consist of a double
layer (bilayer) of phospholipids interspersed with proteins.
 Singer and Nicolson (1972) proposed a working model of plasma membrane known as fluid
mosaic mode.
 The lipid bilayer is retained as the core of the membrane.
 These lipids molecules are present in the fluid state capable of rotating and moving laterally
within the membrane.
 The components of plasma membrane are mobile and capable of coming together to engage in
various types of transient of semi permanent interactions.
Prof. Muhammad Saleem Mughal
 The plasma membrane performs several functions but the main and the most important
functions are protection of cell cytoplasm and to regulate the flow of solutions and material in
an out of the cell with certain limitation.
 These limitation or check in flow across the membrane is called differential or selective
permeability.
 Diffusion or passive transport occurs spontaneously and no extra energy is required to bring
about.
 Osmosis maintains a balance between the osmotic pressure of the intracellular fluid and that of
interstitial fluid.
 Movement of molecules from lower concentration the higher concentration by consuming
energy called active transport.
 Endocytosis is the process in which the cell membrane helps to take in material by infolding in
the form of vacuole.
 In Phagocytosis solid particles are picked and ingested by the cell.
 In Pinocytosis liquid material in bulk. The process of membrane fusion and the movement of
material out of a cell is called exocytosis.
CELL WALL
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Cell wall is the nonliving component of cell.
The chief structural component of plant cell wall is cellulose a polysaccharide.
In addition to cellulose pectin and few other compounds may also be found in cell wall.
A plant cell wall can be differentiated into three regions (i) middle lamella (ii) primary wall (iii)
secondary wall.
 The first formed cell plate works as a cementing layer between two daughter cells and is called
middle lamella.
 At places in the cell wall the deposition of wall material does not take place and these places
are known as plasmodesmata (singular plasmodesma) through which cellular content of
neighbouring cells remain in communication with each other.
 Function of cell wall provided a mechanical support and gives a definite shape and protection
to the cell. It acts like a skeletal frame work of plants.
NUCLEUS
 Nuclear membrane is double membrane structure.
 The nucleus is filled with a protein rich substance called nucleoplasm or karyolympth.
 In the nucleoplasm are numerous fine strands in the form of net work called chromatin net work
or nuclear reticulum which is composed of nucleic acid Deoxyribo nucleic acid (DNA) and
protein.
 The chromatin changes its shape to form chromosomes.
 Chromosomes contain the hereditary units called genes that carry the hereditary information
form generation to generation.
 Chromosomes vary in number from species to species.
 Chromosome is composed of two parts, the arm and the centromere.
 Before cell division each chromosome consists of two threads called chromomers.
 The chromosome has different shapes (metacentric, sub-metacentric, acrocentric or subtelocentric, telocentric) depending on the position of centromere.
 Also within the nucleus is a spherical non-membranous body called nucleolus.
CYTOPLASM
 The cytoplasm has two distinct parts, an outer clear ectoplasm and an inner granular endoplasm
in most cells.
 The cytoplasm exhibits active streaming movements around the inner surface of the cell. This
movement is known as cyclosis.
 The cytosol is a watery solution of salts sugar, amino acids, proteins, fatty acids, nucleotide and
other materials.
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Prof. Muhammad Saleem Mughal
ENDOPLASMIC RETICULUM
 Endoplasmic reticulum is a complex network of channels which extends from plasma
membrane to the nuclear membrane.
 Smooth endoplasmic reticulum is not associated with ribosomes. It is found in steroid
producing like adipose cells interstitial cells glycogen storing cell (liver) and the muscle cells.
 Rough or granular endoplasmic reticulum is heavily coated with ribosome on its outer
cytoplasmic surface.
 Rough ER occurs mostly in protein synthesizing cells.
 It serves as a supporting platform for the ribosome.
 The ER forms a structural frame work of the cell with increased surface for various metabolic
reactions and they themselves take an active part by means of attached enzymes.
 ER also provides conducting pathways for import-export and intracellular circulation of various
substances.
 It also helps in detoxification of harmful drugs, storage and release of Ca ions, detoxification
of chemical and manufacture lipids.
MITOCHONDRIA
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Mitochondria of chondriosomes appear as minute granules, vesicles rodlets threads or strings.
Mitochondria are the centre of aerobic respiration.
The inner membrane forms irregular incomplete partitions called Cristae.
The interior of the mitochondrion contains fluid like organic matrix with a number of chemical
compounds.
 Adenosine triphosphate (ATP) is energy rich compound and it provides energy to the cells of
organs for various activities.
 Mitochondria are known as “Power House” where energy is stored and released wherever and
whenever required by a living body.
GOLGI APPARATUS
 Golgi apparatus like endoplasmic reticulum is a canalicular system with sacs but unlike the
endoplasmic reticulum it has parallel arranged flattened membrane bound vesicles which lack
ribosomes.
 Each of them is disc shaped and consists of central flattened plate like compartments called
cisternae, peripheral network of inter connecting tubules and peripherally occurring vesicles
and Golgian vacuoles.
 Golgi apparatus are especially prominent in glandular (secretory) cells.
 The products of E.R are modified and stored and then sent to other destinations.
 Many polysaccharides secreted by cells, like cell wall and cell plate material in plant cell are
Golgi products.
LYSOSOMES
 There are spherical bodies surrounded by a single membrane originated by Golgi apparatus and
containing digestive enzymes.
 They occur only in the cytoplasm of animal cells.
 When the membrane of lysosomes is ruptured, the cell undergoes chemical breakdown or lysis.
 Since release of the enzymes cause a cell to destroy itself by digesting its won proteins,
lysosomes have been referred as suicide sacs and this process is called autophagy.
 The absence of apparently unimportant lysosomal enzyme “gludosidase” could lead to the
storage of undigested glycogen. Diseases of this type characterized by the deficiency lysosomal
enzyme and the corresponding accumulation of undergraded substrate are called lysosomal
storage disorder.
 Tay sachs disease is characterized by mental retardation, blindness and death by age 3.
 In Gaucher’s disease, liver and spleen enlarge, erosion of long bones and mental retardation in
infantile form occurs.
 In Krabbe’s disease, there is a loss of myelin sheath of neurons accompanied by mental
retardation and death by the age 2 occurs.
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PLASTIDS
 Plastids are especial protoplasmic membrane bound organelles which function as chemical
synthesizers and storage bodies.
 There are three types of plastids e.g. chloroplast, Chromoplast and Leucoplast.
 The most common type of plastid is chloroplast containing chlorophyll which gives plant their
green colour.
 Chloroplasts contain a substantial amount of DNA.
 Chromoplasts have pigments like xanthophylls and carotene.
 The Chromoplasts are responsible for various colour combinations found in flowers, fruits and
other coloured parts except green.
 Leucoplasts are colourless paltids, which develop in the absence of sunlight and are thus
commonly found in all under ground parts of the plants. They store food material.
 Proplastids are immature colourless plastids occurring in cells of meristematic tissues.
 Chloroplasts have an ability to convert solar energy (light energy) into chemical/food energy
by the process of photosynthesis.
 Inside the chloroplast other membranous system arranged into flattered are called thylokoids.
 In some regions, thylokoids are stacked to form structures called grana.
 The fluid outside the thylokoids is called stroma (matrix).
PEROXISOMES
 Peroxisomes are single membrane bound microbodies that contain enzymes for transferring
hydrogen atom to oxygen, forming hydrogen peroxide, a toxic molecule that is immediately
broken down to water by the enzyme catalase.
 Peroxisomes are abundant in cells that are metabolizing alcohol.
GLYOXYSOME
 Each glycoxysome has a layered bounding membrane enclosing a fine granular stroma.
 Glyxysome consists of enzymes that can metabolize some of the molecules involved in the
photosynthesis process and respiration through oxidation of fatty acid.
CYTOSKELTON
 Cytoskeleton is organized into a three dimensional network fibrous proteins.
 It plays fundamental roles in mitosis, meiosis, cytokinesis, cell wall deposition, the maintenance
of cell shape and differentiation.
 There are two major types of cytoskeletal elements found cells; microtubules and
microfilaments.
 Microtubules are hollow cylinder with outer diameter of 25nm.
 Microfilaments are solid with a diameter of 7nm.
 Microtubules are composed of the protein tubulin and microfilaments are composed of protein
actin.
 A single microtubule consists of two actin chain that intertwines in a helical fashion.
 In animals cells and lower plans the microtubules form structures like centriole cilia and
flagella.
 Intermediate filaments are intermediate in size between microtubules and microfilaments.
 They are rope like polymers of fibrous protein but the specific type varies accordingly to the
tissues. In the skin and hair proteins the filaments are made of the protein keratin and they give
mechanical strength of cells.
 Intermediate filaments do not assemble and disassemble.
RIBOSOMES
 Ribosomes are so named because they contain high they contain high concentration of
ribonucleic acid (rRNA) and many proteins.
 These are sites of protein synthesis.
 Ribosomes may be regarded as protein factories.
 Each ribosome consist the larger subunit is dome shaped and smaller one forms a cap on the
surface of larger subunit.
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Prof. Muhammad Saleem Mughal
 The ribosomes are manufactured in nucleolus.
CENTRIOLE
 In the cytoplasm near nucleus of most of the animal cells and the cells of certain lower plants a
centrosome is commonly present.
 The higher plants generally lack centriole.
 Each centrosome consists of two cylinders called centrioles lying perpendicular to one anther.
 During cell division the centrioles replicate and move to opposite side of the cells and thread
like fibers begin to radiate from centriole in all directions called astral rays.
VACUOLE
 Generally vacuoles (except food vacuole) are nonprotoplasmic liquid filled cavities in the
cytoplasm and are surrounded by a membrane called tonoplast.
 The vacuoles in plant cells are filled with cell sap and act as store house, which often plays role
in plant defense.
 In animals cells vacuoles are rich in hydrolytic enzymes.
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Prof. Muhammad Saleem Mughal
UNIT-5
VARIETY OF LIFE
 Viruses are considered to be border line between living and non living
CLASSIFICATION:
 Linneaus is considered as father of taxonomy
 A Character is any attribute or descriptive phrase referring to form, structure or behaviour of a
specific organism for a particular purpose, thus character is anything or any feature whose
expression can be measured or other wise assessed.
 Living organisms are classified on the bases of homologies, comparative biochemistry,
cytology and genetics
 HOMOLOGY: Structures which have common origin resemble morphologically but differ in
function, e.g. arm of man, paws of cat, flippers of whale and wings of bat.
 BIOCHEMISTRY: Important in classifying organisms e.g. bacteria which are difficult to
classify on morphological basis
 CYTOLOGY: The cytological studies of organisms is also important in classification
 GENETICS: Study of DNA and chromosomes plays final role in classifying organisms
 TAXON: Each group on taxonomic hierarchy is called taxon
 BIONOMIAL NOMENCLATURE: Each organism is given name in two words, first word
represents a genus and begins with a capital letter while the second word represents species and
begins with small letter.
FIVE KINGDOM SYSTEM:
 Proposed by R.H.Whittaker (1969) who divided living organisms into five kingdoms on the
basis of level of organization of the organisms and their mode of nutrition
 There are three levels of organizations of living organisms, viz. unicellular Prokaryotes,
unicellular Eukaryotes and multicellular Eukaryotes.
MODIFIED FIVE KINGDOM SYSTEM:
 Proposed by Lynn Marguilis and Karlene Schwartz
 Monera was named as Kingdom Prokaryotae, while protista was named as Protoctista
 Viruses were removed from kingdom Prokaryotae because of their acellular nature.
 Multicellular algae were placed in kingdom Protoctista with their unicellular ancestors
VIRUSES:
 Latin word “venom” meaning Poison
 All viruses are obligatory parasites
 Non cellular, size range from 20nm to 250nm
 First viral disease of plants was studied, it was TOBACCO MOSAIC DISEASE
 Iwanowsky, a Russian Biologist, studied TMD
 Wendell Stanley (1935) first isolated virus of TMD and called it as TMV
 Each virus has a protein coat or CAPSID enclosing a small piece of nucleic acid either DNA
or RNA.
 Capsid is made up of protein sub-units called CAPSOMERES which is characteristic of a
particular virus
 Some viruses have accessory structures called VIRAL ENVELOPLES, TAIL FIBERS
 Viral envelopes help infecting their host by cloaking their capsids.
 Bacteriophages are the most complex viruses made up of five components.
 Classification of viruses depends upon their morphology and nucleic acids.
LIFE CYCLE OF VIRUS:
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Life cycle of bacteriophage consists of lysogenic and lytic cycles.
LYSOGENIC CYCLE: Virus does not kill its host, instead its genome multiplies with its host
LYTIC CYLE: Virus kills its host
TEMPERATE VIRUS: A virus that can go through both cycles.
RHINOVIRUSES: Viruses of the upper respiratory tract
RHABDO VIRUSES: Rod shaped viruses
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Prof. Muhammad Saleem Mughal
 ARBOVIRUSES: Viruses transmitted through arthropod vector
 RETROVIRUESES: RNA viruses
PLANT DISEASES:
 HORIZONTAL TRANSMISSION: A plant is infected from external source through injured
part or through insect
 VERTICAL TRANSMISSION: Plant inherits a viral infection from a parent
HUMAN IMMUNE DEFICIENCY VIRUS (HIV)
 A retrovirus (RNA) enveloped, plus strand virus that attacks T4 (T helper)
lymphocytes of man
 HIV is transmitted through blood or semen, in 90% or cases the transmission is
achieved by sexual contact.
 1-2% of HIV positive cases develops AIDS (Acquired Immuno Deficiency
Syndrome)
 Azidothymidine or zidovudine is the best known drug for treating HIV.
 Brain is the reservoir of HIV
HEPATITIS:
 Inflammation of liver
 It is characterized by jaundice, abdominal pain, liver enlargement, fatigue and fever.
 HEPATITIS A: Caused by unenveloped RNA virus, transmitted through feces of
patient
 HEPATITIS B: (Serum Hepatitis) DNA virus; important health threat
 HEPATITIS C: Enveloped ss RNA virus
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Prof. Muhammad Saleem Mughal
UNIT - 6
THE KINGDOM PROKARYOTAE
KEY POINTS
 The most primitive living organisms evolved 2 billion years ago on earth was prokaryotes.
 Prokaryotes are unicellular organism in which DNA molecules (genetic material) is not
enclosed in proper nucleus.
 They are generally called bacteria.
 They are omnipresent microscopic organisms.
 Bacteria and Protozoa were discovered by Antony Van Leeunwenhoek.
 Bacteria are the smallest and simplest living organism.
 The bacterial cell measures from 0.2 micron (u) to 2u in breadth and 2 to 10u in length.
 If similar cells remain associated after cell division they form colonies.
 The flagella come out from the cell wall in the case of bacteria help in locomotion towards
stimuli, a behavior called taxis.
 Chemotactic or chemotaxis bacteria move towards or away from chemicals.
 Phototactic or phototaxis move towards or away from light.
 Magnetotactic move towards magnetic field and detect earths magnetic field using magnets
formed from iron crystals within their cytoplasm.
 Pilli are hollow small, thin appendages help in conjugation.
 Capsule is a protective shield made up of polysaccharide and protein increase pathogenicity
against phagocytosis.
 Cell wall made up of amino acids sugar and chitin or peptidoglycan, lipoprotein and
lipopolysaccharide.
 Archaebacteria lack cell wall, do not contain peptidoglycan.
 Cell membrane also acts as respiratory structure in the absence of mitochondria.
 Cytoplasm contains glycogen particles and ribosomes.
 The invaginations of cell membrane into the cytoplasm are called mesosomes.
 Mesosomes are found in the form of vesicles, tubules or lamellae; perform function of DNA
replication cell division respiration and export of enzyme.
 Bacterial chromosome or chromatin body is a concentrated structure of DNA found in a
cytoplasm in a region called nucleoid.
 An extra chromosomal circular DNA is also found called plasmid.
 Coccus round or Berry shaped.
 Bacilli rod shaped may be flagellated.
 Spirilla or cork screw shaped e.g. spirochaeta.
 Vibro or comma shaped e.g. vibris cholera colonial form.
 Diplo = two, strepto = in chain, stephlo = in bunch, tetrad 4, sarcina = cube of eight.
 Saprotrophes or saprotrophic bacteria get their food organic compounds from dead matter,
humus (organic compound of soil).
 They break down complex substances of humus to simpler compounds.
 Majority of bacteria get their food from host without harming it e.g. Rhizobium radiocicola live
in the nodulated roots of leguminous plant to fix N2.
 Parasitic bacteria get their food from living host and harm it. e.g. T.B bacteria, Pneumococcus
bacteria etc.
 Autotrophic bacteria can synthesize organic compound from simple inorganic substance.
 There are two types of autotrophic bacteria (i) photosynthetic (ii) chemosynthetic.
 Photosynthetic bacteria utilize H 2 S in place of H 2 O and produce S instead of O 2 .
 Photosynthetic bacteria utilize light energy for the synthesis of their food.
 Chemosynthetic bacteria use energy of oxidation for the synthesis of their food.
 The bacteria which require low concentration of O 2 for respiration as well as growth called
micro-aerophilic.
 Bacteria which killed in the presence of O 2 called obligate anaerobes.
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Prof. Muhammad Saleem Mughal
 Bacteria which can only survive in the presence of O 2 called obligate aerobes.
 The movement of bacteria is due to flagella toward stimuli called taxis movement ie.
Chemotaxis or chemotactic toward or away from chemical phototactic towards or away from
light and magnetotactic towards magnetic magnets.
 Growth in bacteria means increase in their colony or increase in the rate of reproduction.
 Growth of bacteria requires favourable conditions like temperature, nutrients, availability pH
and ionic concentration.
 There are 4 phases recognized in bacterial growth.
 LAG Phase LoG stationary, Death.
 LAG phase Inactive phase where cell division does not occur LoG phase rate of cell division is
very high growth rate is fast.
 Stationary phase rate of cell division is equal to death rate.
 Death rate is more rapid than multiplication.
 Reproduction asexual reproduction by Binary fission in favourable conditions; fastest mode of
reproduction.
 Another method of asexual reproduction in bacteria is endospore formation. Takes place in
unfavourable condition.
 Genetic recombination in which genetic material of two types of bacteria takes place to form a
new type of bacteria.
 Three methods of genetic recombination are found in bacteria.
 Conjugation in which genetic material of one bacterium is transferred to another bacterium
through a tube called conjugation tube or cytoplasmic bridge.
 Conjugation comes in light as a result of Laderberg and Tatum in 1946. They use Escherichia
coli bacteria.
 Transduction in which genetic material of one bacterium is transferred to another bacterium by
a bacteriophage.
 This method was carried out experimentally by Laderbereg and Zinder in 1952.
 Transformation is the method of genetic recombination where one type of bacterium change
into another type.
 F. Griffith in 1928 was noticed this process 1st time when he was working on two strains of
Pneumococcus.
 He also found that the transforming material is the heredity material.
 It provided the bases for establishing that DNA is the genetic material.
 Nitrifying bacteria convert protein and other Nitrogenous compound into nitrates.
 Bacteria which convert cellulose into glucose produce an enzyme called cellulose, live in the
colon of herbivores animals; thyrothycin subtilin are the antibiotics derived from bacteria.
 Riboflavin (vitamin) produced by Clostridium.
 Typhoid, tetanus, food poisoning, diphtheria, tuberculosis are the animal diseases caused by
bacteria.
 Black rot of cabbage citrus canker fire blight of pear and apple, ring rot of potato etc are the
plant disease caused by bacteria.
 A process of induction of specific immunity by injecting antigen antibodies or immune cells
called Immunization.
 One of the procedures of immunization is vaccination.
 Vaccination is the inoculation of host with inactive or weakened pathogens or pathogenic
products to stimulate protective immunity.
 Polio vaccine is taken orally.
 Antibiotics are chemical substances produced by certain micro organisms that inhibit or kill
some other micro organism.
 Penicillin was the first antibiotic derived from fungi in 1940.
 Antibiotics work against a wide range of bacteria called Broad spectrum antibiotics.
 The target of antibiotics is cell wall, plasma membrane and biosynthetic processes of proteins
and nucleic acid.
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Prof. Muhammad Saleem Mughal
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Unicellular, prokaryotes photosynthetic, aquatic, colonial organisms.
Protoplasm is differentiated in chromoplasm and centroplasm.
Asexual reproduction by hormogonia, zoospores, akiniets and fragmentation.
Nostoc is the example of fresh water cyanobacteria.
Nostoc forms filamentous colony, filaments mixed a gelatinous material from a ball like
structures called coenobium.
Floats in water.
A filament looks like a chain of beads called moniliform.
The chromoplasm is coloured due to the presence of chlorophyll, xanthophylls, carotene, phycocyanin and
phycoerythrin.
The larger oblong colourless cells with thick wall called heterocyst, it is a centre of nitrogen fixation.
The portion of filament between two heterocysts called hormogonium.
The non-motile spores formed from certain vegetative cells during unfavourable condition
called Akinites.
Nostoc anabena is used as nitrogen fertilizer.
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Prof. Muhammad Saleem Mughal
UNIT 7
THE KINDOM PROTOCTISTA
 Eukaryotes (unicellular as well as multicellular; autotrophic as well as heterotrophic)
containing ancestral groups of fungi, plants and animals
 The most diverse and controversial group
 Plant like Protoctists = Algae, e.g. Chlorella, Ulva
 Fungi like Protoctists= Primitive Fungi, e.g. Slime molds, water molds (Phytophthora)
 Animal like Protoctists= Protozoa e.g. Amoeba, Paramecium, Euglena
PLANT LIKE PROTOCTISTS: Algae (algin = sea weed)
 Photosynthetic aquatic, autotrophs responsible for more than half of the amount of
photosynthetic activity
 Algae contain cells wall (cellulose) and chlorophyll b like plants
 Classification of algae is largely based on the pigment composition
 Zygote is not protected by parent body
CHLORELLA:
 Fresh water unicellular alga; helps in research in photosynthesis
 Pyrenoid is absent in chloroplast
 Reproduces asexually by APLANOSPORE only
 Source of antibiotic CHLORELLIN
 ULVA: Marine water multicelluar alga
 Commonly called “sea lettuce”
 Thallus is attached with rocks with unicellular thread like cells HOLD FAST
 Ulva exists in two types; SPOROPHYTE (diploid) having 26 no of chromosomes and
GAMETOPHYTE (haploid) having 13 no of chromosomes
 Both sporophyte and gametophytes are morphologically indistinguishable hence called
ISOMORPHIC
 Reproduction is both asexual as well as sexual with isomorphic alternation of generation
 Sporophyte reproduces asexually by eight to sixteen haploid quadriflagellated zoospores
 Spores produce gametophyte
 Gametophyte produce biflagellated haploid gametes
 After syngamy of gametes, a zygote is produced with develops into sporophyte
EUGLENA:
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Features of both plants as well as animals
Unicellular, flagellated, chloroplast bearing but without cell wall
Cell wall like PELLICLE of proteins is present
It can go through heterotrophic nutrition also
FUNGI LIKE PROTOCTISTS:
 Non photosynthetic and body formed of hyphae
 Cell wall of cellulose
 Two groups; Slime molds and water molds – Oomycetes
SLIME MOLD:
 PLASMODIAL STAGE: Giant Amoeba like multinucleated, creeping stage ingesting
bacteria from the surface of rotting logs leaves
 In dry conditions, it gives rise fruiting bodies SPORANGIA which produce a large number of
microsopic non motile SPORES
 Spore upon germination produce biflagellated gamete.
WATER MOLD: Phytopthora infestans
 Pathogenic organism which causes late blight of potato
 Hyphae are endophytic, branched, aseptate, coenocytic, hyaline and nodulated.
 Haustoria absorb food
 Reporduces both asexually as well as sexually
 Sexual reprocution is oogamy
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Prof. Muhammad Saleem Mughal
ANIMAL LIKE PROTOCTISTS: PROTOZOA
 Unicellular, heterotrophic aquatic organisms
 Five classes: Flagellata, Ciliata, Suctoria, Sarcodina and Sporozoa
 FLAGELLATA bears one or more flagella; considered to be the basic stock from which
evolved other protozoa as well as plants and animals.
 Euglena is a free living flagellate while Trypanosoma is human parasite which causes
‘African sleeping sickness’
 SARCODINA lack organelle for locomotion. They give out pseupodia.
 Amoeba proteus is free living while Entamoeba histolytica causes “Amoebic Dysentary” in
man
 Marine shelled protozoa have deposited billions of skeletons, the “Radiolarian ooze” and
“Globigerina ooze” on the floor of the oceans. The ooze is studies for oil search in ocean.
 CILIATA: Bear cilia for locomotion
 SUCTORIA: Bear cilia in the early stage, later loose them and become sessile
 Predators
 SPOROZOA: All endoparasites of vertebrates; no organelles for locomotion
 Reproduce asexually as well as sexually
LIFE CYCLE OF PLASMODIUM;
 Plasmodium, a sporozoan causes MALARIA in warm blooded animals especially man
 Life cycle requires two hosts; Man for asexual reproduction (schizogony), and female
Anopheles mosquito for sexual reporuction (sporogony)
 ASEXUAL CYCLE IN MAN (SCHIZOGONY)
 A person acquires infection through bite of infected female Anopheles mosquito which
introduces SPOROZOITES stage of Plasmodium in man during her blood meal
 Sporozoites invade hapatocytes (live cells) where they pass through the stages of Schizont
and exoerythrocytic (EE) merozoites
 Each EE merozoite invades a RBC; grows to become signet-ring shape trophozoite, then
amoeboid trophozoite, then schizont which breaks up into numerous Erythrocytic merozoites. The
later burst the RBC and attack new RBC.
 Some of amoeboid trophozoite rather than forming E. Merozoites develop into
GAMETOCYTE.
 Two gametocytes are formed; Microgametocytes and Megagametocytes which are sucked up
by female Anopheles mosquito
 SEXUAL CYCLE IN MOSQUITO (SPOROGONY)
 Gametocytes develop into male and female gametes respectively in the stomach of mosquito
 The Zygote become ookinite which penetrate the stomach cell where it develops into
OOCYST. The later divides to produce numerous sporozoites.
 The sporozoites are released into the haemocoele and find their way to the salivary glands of
female Anopheles mosquito
 SYMPTOMS OF MALARIA:
 Appear when infected RBCs burst
 Fever with chill, shivering, head ache, nausea, loss of appetite, constipation, insomnia.
Symptoms disappear with profuse sweating after few hours. Then there is recurrence of
symptoms.
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Prof. Muhammad Saleem Mughal
UNIT 8
19
FUNGI
 Multicellular, Achlorophyllous, coenocytic, Heterotrophs, Cell wall (Chitinous) present
 Fungi and bacteria are the decomposers of the biosphere
 Body is mycelium (consists of numerous threads called Hyphae)
 Grow best in hot, humid and dark conditions
 Store surplus food as lipid droplets or glycogen
 Tolerate a wide range of pH, temperature and osmotic presure.
 Mitosis is characteristic known as NUCLEAR MITOSIS in which nuclear membrane persists
and spindle is formed inside nucleus
 All fungal nuclei are haploid (except diploid zygote Fungal spores develop from hyphae
 Many fungi are symbionts with other organisms
 Coenocytic hyphae where the nucleis of each cell is embedded in the cytoplasm without a cell
wall
 Eg. Zygomycota, Oomycota
 Absorptive heterotrophs; Saprotrophs (Decomposers), Parasites, Predators, Mutulistic
 SPROBES have modified anchoring hyphae, Rhizoids
 PARASITIC fungi absorb nutrients with special hyphae tips called Haustoria
 Obligatory Parasites: Grow only on their living hosts, E.g. mildew. Rusts
 Facultative Parasites: can grow on minimal culture medium also.E.g. Agalinis, Aureolaria,
and Seymeria.
 PREDATORS: Attacks and kills its prey
o E.g. Oyester mushroom (Pleurotus ostreatus), a carnivorous fungus which paralyses
the nematodes and absorbs the nutrients to fulfil its nitrogen requirement.
o Arthrobotrys traps soil nematodes
 SYMBIOTIC: Association for mutual benefits
o E.g. Lichens: certain fungi (mostly ascomycetes and imperfect fungi, and few
Basidiomycetes) with either green algae or a cyanobacterium or sometimes both.
o Most of the visible part of Lichen consists of fungus and algal components are present
in hyphae
o Fungus protects the algal components from strong sunlight and desiccation and itself
gets food.
o Lichens are bioindicators of air pollution??????
LICHENS
 Soredia are the asexual reproductive part of lichens, containing both symbionts. Rhizines
may be present to anchor the lichen
 Bioindicators are species used to monitor the health of an environment or ecosystem.
 The disappearance of lichens in a forest may indicate environmental stresses, such as high
levels of sulfur dioxide, sulfur-based pollutants, and nitrogen-oxides.
MYCORRHIZZAE (FUNGUS ROOT)
 Association of certain fungi and roots of vascular plants
 The fungal hyphae dramically increase the absorptive surface of roots and help in direct
absorption of P,Zn,Cu and other nutrients from soil
 The plants supplies organic Carbon to the fungal hyphae
 ENDOMYCORRHIZAE: Fungal hyphae penetrate the outer cells of plant root forming
coils, swellings and minute branches and also extend out into surronding soil.
 ECTOMYCORRHIZAE: Hyphae do not penetrate the cell but surrounds it.They are mostly
formed with Pines.
REPRODUCTION IN FUNGI
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Repdocuce asexually as well as sexually (except imperfect fungi)
ASEXUAL REPROCUTION: spores, conidia, fragmentation, budding
Prof. Muhammad Saleem Mughal

SPORES:
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Produced in sporangia
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Asexual as well as sexual, Haploid, non motile being dispersed by wind, insects,
animals, or rain water
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CONIDIA:
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Non motile asexual spores usually in chains
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Produced from modified hyphae, CONIDIOPHORES (not in sporangia)
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FRAGMENTATION:
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Some fungal hyphae break off from the mycelium to give rise new mycelium
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BUDDING: Unicellular yeast gives out tiny outgrowth or bud which may separate
and grow into a new individual
SEXUAL REPODUCTION:
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Fusion of haploid nuclei and meiosis common
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Two hyphae of same mating type come together and their cytoplasm fuse
(Plasmogamy) followed by nuclear fusion (Karyogamy)
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HETEROKARYOTIC (Dikaryotic): In Basidiomycetes and Ascomycetes, the two
haploid nuclei coexist and divide in the same hyphae for the most of the life of the fungus.
CLASSIFICATION: Four major divisions / phyla based upon reproduction:
 zygomycota, ascomycota, basidiomycota, deuteromycota
 ZYGOMYCOTA
 Smallest group; E.g. Mucor, Rhizopus
 Aseptate hyphae except sprangia or gametengia
 Produces temporarily dormant structures called ZYGOSPORES
 ASCOMYCOTA
 Reproductive structure is microscopic club shaped ASCUS (Pl. Asci).
 Zygote, the only diploid nucleus in the life cycle formed within ascus
 ASCOCARP: Fruiting bodies, visible portion of a morel or cup fungus formed by densely
interwoven hyphae, here the asci develop
 ASCOMYCOTA
 Asexual reproduction takes place by spores, CONIDIA formed within conidiohpores.
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Prof. Muhammad Saleem Mughal
UNIT 9
KINGDOM PLANTAE
PLANT?
 Multicellular, Eukaryotic, Photosynthetic Autotrophic organisms
 Cell wall usually made up of Cellulose
 Primarily terrestrial
 Heteromorphic alternation of generation
 Tendency of Embryo development and protection
TERRESTRIAL ADAPTATIONS
 Protection against desiccation; develop cuticle made up of Wax, Cutin.
 Produce Lignin in woody plants for harder cell wall
 Sporopollelin production provide resistant against environmental damage
 Protection of Gametangium and Sporangium
ALTERNATION OF GENERATION: Two types, Isomorphic & Heteromorphic
ISOMORPHIC
 Gametophyte and sporophytes are morphologically indistinguishable
 Both are photosynthetic
 Gametophyte haploid
 Sexual rep. Isogamy
 Sporophyte diploid
HETEROMORPHIC
 Gametophyte and sporophytes are morphologically different
 Only gametophyte is Photosynthetic
 Gametophyte haploid
 Sexual reproduction Heterogamy
 Sporophyte diploid
CLASSIFICATION OF PLANTS
Divisions Bryophyta, Tracheophyta
BRYOPHYTA: LIFE CYCLE:
Sexual Reproduction:
 Through gametes produced by gametophytes
 Gametes develop into GAMETENGIA
 ANTHERIDIUM: male gametengium produced flagellated sperms
 They need water to move their flagellated sperms
 ARCHIGONIUM: Female gametangium produces female gamete, egg within the protective
jacket of archigonium
 Zygote develops into an EMBRYO within the archigonium
 This develops into the sporophyte generation
Asexual Reproduction:
 Through spores produced by sporophyte
 Sporophyte grows from the interior of the archegonium and is composed of three parts
o Foot (attaches to archegonium)
o Seta - a stalk-like structure
o Capsule - produces spores
 Sporophyte produces spores via meiosis.
 Spores are released and grow into more of the gametophyte generation.
o Class HEPATICAE (Liver worts) e.g. Riccia, Marchantia
o Class MUSCI (Mosses) e.g. Funaria
o Class ANTHOCEROTAE (Horn worts)e.g. Anthoceros fusiformis
HEPATICAE (Liver Worts)
 Body divided into Liver like lobes
 Gemma cups for asexual reproduction
 Male and Female receptacles are distinguishable
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Prof. Muhammad Saleem Mughal
MUSCI (Mosses)
 Grow in the form of mat
 Main plant is Gametophyte
 Each gametophyte holds the substratum with elongated cells, RHIZOIDS
 Most photosynthesis occurs in the upper part of thallus which has many stem like or leaf like
appendages, PARAPHYSIS which help to prevent drying of the sex organs
 Main plant is Gametophyte
 Male gametangium – Antheridium produces flagellated sperms, Antherozoids
 Female gametangium, Archegonium produces ovum
 After fertilization
heterotrophic sporophyte develops.
ANTHEROCEROTAE (Horn Warts)
 Most advance group
 Elongated capsules that grow “horn like” from the gametophyte
 Sporophyte has stomata and chloroplast so it can perform photosynthesis
 Meristem present
 Due to these special features, the sporophyte can continue to survive even after the death of
gametophyte
DIVISION TRACHEOPHYTA
 Psilopsida, Lycopsida, Sphenopsida, Pteropsida, Spermopsida
PSILOPSIDA
 Oldest grouop
 No roots, No leaves, No flowers
 Sporophyte is independent. It is green, dichotomously branched stem
 Sporangia at the tip
 Homosporous sporophyte; produces spores by meiosis
 Gametophyte independent, small, monoecious
 No cambium hence no secondary growth
 Two living genera; Psilotum and Tmepespteris
 Gametophyte bears both archegonia and antheridia
 E.g. Rhynia, and extinct species
RHYNIA
 One of the most primitive vascular plant
 Named after the village Rhynia where the fossil was discovered
 Main plant is sporophyte which is slender, dichomoously branched creeping rhizome
 Rhizoids instead of roots
EVOLUTION OF LEAF
One veined leaf (MICROPHYLLOUS)
THEORY A:
 Evolved as a thorn like outgrowth (enation) emerged on the surface of the naked stem. Later
vascular tissue developed in it
THEORY B:
 Another possibility is the reduction in the size of a part of the leafless branching system of the
primitive vascular plant.
Many veined leaf (Megaphyllous)
 Modification of forked branching system of the primitive plants.
 First step: Restriction of the branches to a single plane
 Next step: Filling of the spaces between the branches and vascular tissue
LYCOPSIDA (Club mosses)
 True roots, stem, leaves (microphyllous) present
 Some leaves modified into sporophyllous bearing spornagia
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Prof. Muhammad Saleem Mughal
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Sporphyllous are also present at the tip
Sporophyllous form cone or strobilus.
Lycopsids are called club mosses because cone is like club
Homosporous (Lycopodium), Hetersprous (Selaginella)
Gametophytes, self feeding, mono or dioceous
Only 5 living genera among them Selaginella and Lycopodium
Formed earth’s first forest
EVOLUTION OF SEED
 Homospory
 Heterospory
 Developent of integument for megasporangium: Protection of sporangia by enveloping
structures such as outgrowth from sporophyte that later became the integument of sporangium
 Retention of megaspores in sporangia to develop female gametophyte
SPHENOPSIDS
 Common name “horse tail”
 True roots, stem and leaves present
 Stem, hollow and jointed
 Whorls of leaves occur at each joint
 Extinct species showed cambium but not modern
 Terminal cones for spore production
 Homosporous
 Monocious gametophyte
 E.g. Equisetum
PTEROSIDA (Fern)
 True roots, stem and leaves present
 Stem are erect or prostate
 In some leaves are simple but mostly it is compound . Some are non-reprouctive without
sporangium
 Some have sporangium called Sporophylls
 Homosporous
 Small self feeding, monoceious gametophyte
 E.g. Dryopteris (Aspidium)
SPERMOPSIDA
 True roots, stem, leaves, flowers and seeds present
 Gametophyte is much reduced, non-photosynthetic; embryo is well protected
 Embryo is enclosed in seed
 Gymnosperm, Angiosperm
GYMNOSPERM: (Gymnos=naked; Sperma=seed)
 Plants without fruit
 Seeds are naked (ovule is not covered by ovary
 Pteridospermae: seed formed; extinct
 Cycade: Ancient group – palm like; generally called Sago plants – tropical region; large palm
like leaves; generally called “sago palms”
 Ginkgoae: or median hair tree – lawn plant
 Conifers; Ginkgo – the only living type
ANGIOSPERM: (Angion=Cup or vessel)
 Seeds enclosed in fruit or ovule in ovary
 Flower: A short length of stem with modified leaves
 Four whorls of floral leaves are
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Prof. Muhammad Saleem Mughal
o Calyx
Sepals
o Corolla
Petals
o Andorocium
Stamen
o Gyonecium
Carpel
VASCULAR PLANTS: AS SUCCESSFUL GROUP OF LAND PLANTS
 Gametophyte reduced; protected by sporophyte
 Fertilization is water independent
 Gametes non-motile
 Development of pollen tubes
 Production of seeds
 Xylem and sclerenchyme are lignified for providing support.
 Secondary growth
 True roots
 Cuticle: a waxy coating outside epidermis to prevent loss of water
 Stomata: on outer epidermis
 Adaptation for hot , dry environment
DICOTYLEDONS & MONOCOTYLEDONS
 Angiosperms are divided into two groups
 The basic distinguishing feature are embryonic leaves (cotyledons)
 Cotyledons are found in the seeds of these plants
DICOT FAMILIES: Rosaceae, Solanaceae, Legume families (Fabeaceae, Mimosaceae, Ceasalpineaceae)
Rosaceae: Rose family
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Rosaceous corolla: Large showy petals
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Stamens numerous; polyandrous; Monocarpellary or polycarpellary syncarpous may
be apocarpous
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Important for ornamental, rose oil, walking sticks, food value, etc
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Familiar Plants:
o Pyrus malus
Apple
o Pyrus communis
Pear
o Prunus persica
Peach
o Prunus amygdalus
Almond
o Rosa indica
Rose
Solanaceae: Night shade or Potato family
 Flower actinomorphic; Pentamerous; Stamens 5, epipetalous; Ovary bilocular, obliquely
placed; placentation axile; Fruit berry or capsule
 Familiar Plants:
o Solanum tuberosum
Potato
o Solanum melongena
Brinjal
o Lycopersicum esculentum
Tomato
o Capsicum annum
Red Pepper
o Petunia alba
Petunia
o Solanum nigrum
Black night shade
o Datura alba
Thorn apple
o Nicotiana tobacum
Tobacco
LEGUME FAMILIES
FABACEAE: Papilionaceae / Pea family
 Papilionaceous corolla; Stamen 10, diadelphous; Monocarpellary; High source of protein food
(pulses), oil and forage, provide medicines; Excellent timber
 Familiar Plants:
o Lthyrus odoratus
Sweet Pea
o Arachis hypogea
Pea nut
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Prof. Muhammad Saleem Mughal
o
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Cicer arietinum
Dalbergia sisso
Pisum sativum
Sesbania aegyptica
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Gram
Red wood
Edible Pea
Sesbania
Mimosaceae: Acacia family
 5 fused sepals; 5 free or fused petals; Stamen monoadelphous; Monocarpellary
 Important for wood, fuelwood, charcoal , some medicines, Katha
 Familiar plants
o Acacia nilotica
Gum tree (Bauble or Kikar)
o Albizzia lebbek
Sisis
o Mimosa pudica
Touch me not
o Acacia catechu
Katha plant
Ceasalpineaceae
 Casia Family; 5 polysepalous; 5 polypetalous; 10 stamens, polyandrous few staminodous
 Monocarpellary
 Important for medicines, ornamental, food purposes
 Familiar Plants
o Tamarindus indica
Tamarind (imli)
o Cassia fistula
Amaltas
o Parkinosa roxburgai
Vilayati kikar
POACEA/GRAMINAE (Grass family)
 Flowers bisexual; Perianth; 3 to 6 stamens free, verstile anthers; Gynoecium monocarpellary
 Important for food, fodder, ornamental; Cereals and millets belong to this family
 Familiar Plants
o Triticum indicum
Wheat
o Avena sativa
Oats
o Zea mays
India corn
o Oryza sativa
Rice
o Saccharum officinarum
Sugar cane
Prof. Muhammad Saleem Mughal
UNIT NO – 10
THE KINGDOM ANIMALIA
(PORIFERA – CNIDARIA)
DIVERSITY AND COMPLEXITY
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A total of about 1.3 million species of animals are included in this kingdom.
It constitutes around 75% of the total known species of living organisms.
True land dwelling forms are found in phylum arthropoda and chordata.
Animals are though to be arisen from an ancestral colonial, probably volvox like protist
(protoctist).
 Multicellular animals have arisen from the protista at least three times.
ANIMAL CLASSIFICATION
 A true animal is now defined as “a eukaryotic, multicellular, heterotrophic organisms which is
diploid and developed from an embryo formed by the fusion of two different haploid gametes.
 The kingdom Animalia is divided into 33 groups called phyla.
 This classification or grouping of animals is called taxonomy or systematics.
 It is carried out primarily on the basis of their evolutionary relationships.
 Clues to these relationships are found in (i) the comparative study of their morphology
(general appearance) and (ii) their internal architecture which includes their cellular
organization, symmetry and the embryological developmental pattern of their coelom and
blastopore etc.
 The structure of DNA and the study of their comparative biochemistry and physiology also
help in tracing their relationships.
 An animal starts its life as a zygote which is a diploid cell.
 Gastrula has a hollow sac having an opening called blastopore.
 Porifera is group in a separate sub kingdom parazoa because its members lack a proper tissue
organization.
 Eumetazoa (true metazoans) have tissues organized into organs (in the lower groups) and
organs into organ systems (in higher forms).
 Germ layers, are called ectoderm, endoderm and mesoderms are the outer, inner and middle
layers, respectively.
 Cnidarians are called diploblastic.
 Symmetry is the overall shape of an animal body.
 Animals that have no plane of symmetry are said to be asymmetrical.
 A body with radial symmetry has one main axis around which body parts are arranged and
organism can be divided into identical halves in any plane that passes through the main axis.
 A bilaterally symmetrical animal can be divided into identical right and left halves only by a
cut through the mid-line of its body.
 The bilaterally symmetrical animal phyla may be divided into three groups: Acoelomata
(Platyhelminthes); Pseudocoelomata (Aschelminthes) and Coelomata (from Annelida to
Chordata).
 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.
 Blastopore is the opening, which develops in an embryo at the gastrula stage.
 In group protostomata, the blastopore eventually becomes the mouth of adult.
 In group deuterostomata, the blastopore develops into anus and a second opening which
develops later forms the mouth.
 Out of the major coelomata phyla, annelida, mollusca and arthropoda are protostomates while
echinodermata and chordate are deuterostomates.
PHYLUM PORIFERA
 Phylum porifera is the simplest living animals usually called sponges.
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Prof. Muhammad Saleem Mughal
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They have thousand of spores called ostia.
These pores are connected with a system of canals through which water flows.
Sponges are usually asymmetrical, sessile and aquatic organisms.
They lack mouth, intestine, respiratory, excretory and nervous systems.
A sponge may be described as an assemblage of loosely organized cells rather than a well
defined multicellular organism.
The spongocoel may be a single cavity or divided and sub-divided into thousands of small
chambers and canals thus increasing the surface area available.
Between pinacocytes and choanocytes, there is gelatinous mesenchyme, which consists of
amoebocytes and spicules.
Spicules may be calcareous or siliceous and constitute the skeleton of sponges.
The skeleton of bathroom sponges however, is a network of spongin fibres.
Most sponges are hermaphrodite whereas in a few sexes are separate.
Eggs and sperms are formed by amoebocytes.
Asexual reproduction takes place either by regeneration or fragments of sponges or by spore
like Gemmule formation (budding).
Gemmules are actually nutrient laden amoeboid cells surround by layers of epithelial cells.
PHYLUM CNIDARIA
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Phylum cnidaria is also commonly called coelenterata.
Cnidarians are all aquatic.
There are radially symmetrical and diploblastic.
Their body wall encloses a hollow cavity, the gastro-vascular cavity or coelenteron.
The cnidarians have no respiratory, excretory or circulatory systems.
All cnidarians are carnivoruous.
They paralyse or kill their prey with the help special stinging cells called cnidocytes hence the
name cnidaria.
In between these two cellular layers is a plate of non-cellular gelatinous mass called
mesoglea.
As a group cnidarians have two distinct body form polyp and medusa.
Polyps are cylindrical with mouth and tentacles situated at the upper end.
Medusae on the other hand are umbrella shaped whose mouth and tentacles are on the lower
surface.
Some cnidarians alternate between two body types (polyp and medusa) during their life
cycles.
Many cnidarians live as a part of a large colony in which many individuals become physically
attached to one another and occur in many different forms or zooids.
The occurrence of a species in two or more structurally and functionally different kind of
zooids is known as polymorphism.
Many polypoid cnidarians secrete certain chemicals which form a hard but dead protective
covering around them. These coverings are of various shapes, sizes and chemical composition
and are called corals.
Coral reefs are underwater limestone ridges near the surface of the sea.
These are usually formed by the combined secretions of several species of coelenterates and
other carbon precipitating protoctist organisms.
Coral reefs which are usually restricted to warm shallow waters provide a heaven to a large
number of marine species.
Jewellary and other decorative items are carved from the red corals.
No other phylum of animals is thought to have evolved from cnidaria.
Phylum cnidara is divided into three classes: Hydrozoa, scyphozoa and Anthozoa.
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Prof. Muhammad Saleem Mughal
THE KINGDOM ANIMALIA
(PLATYHELMINTHES – ARTHROPODA)
PHYLUM PLATYHELMINTHES
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They are soft bodies or ribbon shaped worms.
Of all the animals that have a head platyhelminthes are the least complex.
They have a mouth which opens into a gut but no anus.
They are acoelomate, bilaterally symmetrical, triploblastic animals with organs and organ
systems.
They have a much branched intestine and a network of excretory tubule with a large number
of ciliated protonephridia (flame cells).
Circulatory and respiratory systems are absent.
Flat worm are mostly hermaphrodite.
The parasitic flat worms which complete their life cycle in one or two hosts called Monogenic
and Digenic, respectively.
Platyhelminthes have developed a number of adaptations for their parasitic mode of life.
Among these are loss of ciliated epithelium, presence of cuticle, organs of attachment, high
reproductive potential, high egg laying capacity, reduction or loss of gut, etc are important .
PHYLUM NEMATODA – ASCHELMINTHES
 Nematodes have elongated, bilaterally symmetrical, triploblastic and cylindrical bodies with
pointed ends.
 They are basically constructed as a tube within a tube body plan.
 Between the tubes, there is a fluid filled body cavity the pseudocoele.
 Body wall being covered over by a non living cuticle.
 Gut is complete.
 Circulatory and respiratory systems absent.
 They are dimorphic males being shorter than females.
 Millions of human beings in the world are infected with Ascaris. It lives as an endoparasite in
the intestine of man.
 The thread worms like Wuchereria, transmitted by blood sucking mosquitoes, inhabits the
lymphatic vessels of many animals including man. It produces a disease called Filariasis.
 Another common nematode parasite Ancylostoma, the Hook worm whose larvae can
penetrate through the skin of man.
PHYLUM ANNELIDA
 Annelida commonly called segmented worms have ring like external segments.
 They are all coelomates with an organ-system level of body organization.
 Their segmentation is said to be metameric because external segmentation corresponds with
internal segmentation and some of their organs such as excretory and reproductive organs are
repeated in each segment.
 Chitinous chaetae also called setae with or without parapodia are usually present in the most
of annelids.
 The excretory organs are a pair or more tubular nephridia per segment.
 Respiration takes place by diffusion through the moist skin.
 Annelida is the first group to have a closed type circulatory system.
 Blood is usually red with haemoglobin dissolved in it
 Segmentation increases flexibility allowing various parts of the body to bend independently
of the other parts.
 The coelom improves swimming or burrowing activities of the annelids by serving as a
hydrostatic skeleton..
 Many annelids are active free swimming predators.
 Leeches are ectoparasite.
 Earthworms feed upon dead organic matter.
 Oligochaetes evolved from polychaetes whereas leeches evolved from oligochaetes.
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 Phylum annelida is divided in to three classes mainly on the basis of number and type of
locomotory organs.
 Polychaetes are usually free living active swimmers or sedentary filter feeding tubuculous
forms. They are mostly marine having a pair of lateral flap like fleshy lobes the parapodia on
each segment of the body.
 Oligochaeta are usually terrestrial free living burrowing forms without parapodia but with few
setae per segment arranged in a ring.
 Setae and parapodia both are absent instead an anterior and a posterior suckers are present .
PHYLUM MOLLUSCA
 Mollusca are soft bodies animals with an external and some an internal shell.
 It is the second largest phylum.
 The smallest mollusks are not bigger than the sand grain whereas the giant squids are the
largest invertebrate.
 They are mostly unsegmented.
 Majority are provided with a rasping feeding structure, the radula.
 Respiration takes place by gills in aquatic form and by a rudimentary lung in terrestrial forms.
 They share at least three common characters (i) A head foot (ii) A dorsal visceral mass and
(iii) A mantle.
 In most of the mollusks sexes are separate and fertilization takes place in water.
 They all pass through a trochophore larva stage.
 Many of gastropods become secondarily asymmetrical by the twisting of visceral mass at 180
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by a phenomenon called torsion. Their bodies are enclosed in a shell which consists of a
right and a left piece.
 The muscular foot is ventral and laterally compressed.
 Foot in cephalopods is transformed into sucker bearing tentacles and arms.
 The inner lustrous layer of shells in pelecypods (bivalvia) is a mixture of calcium carbonate
and proteins is called Necre or mother of pearl.
PHYLUM ARTHROPODA
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Arthropod is the largest phylum of the animal kingdom.
Arthropods have heterornomous segmentation.
The bodies of the most of arthropods are divided into a head, a thorax and an abdomen.
Tissue spaces in arthropod are called haemoceol because they are filled with blood.
Respiration takes place through gills in aquatic forms, by tracheae in insects and by book
lungs in scorpions.
Excretory organs are mostly malpighian tubules.
Metamorphosis is a set of changes which transforms a larva into its developed adult form.
Metamorphosis is said to be complete when a larva hatches out of the egg and develops into a
resting stage the pupa which in turn transforms into an adult.
A significant advancement in this group is their jointed appendages hence the name
Arthropoda.
Another important feature of Arthropoda is their water proof, chitinous exoskeleton.
The mechanism of regular changing over of exoskeleton and formation of the new one is
called Moulting or Ecdysis.
Farming of honey bees called apiculture and those of silk worms called sericulture.
Merostomata is a small group of marine arthropods in which mouth is surrounded by many
small plates.
Arachnida is a group of terrestrial arthropods with four pairs of walking legs.
Crustacea possess two pairs of antennae, a pair of mandibles and two pairs of maxillae around
their mouth. Their body consists of a head and a vary long trunk consisting of many similar
segments.
The study of insects is called entomology.
Class insecta is also called Hexapoda because they possess on their thorax three pairs of
walking legs.
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Prof. Muhammad Saleem Mughal
 The group insect with wings is called pterygota whereas the group without wings is called
Apterygota.
 A pair of antennae on head is also a characteristic of insects.
 Fleas are ectoparastite on many warm blooded animals.
THE KINGDOM ANIMALIA
(DEUTEROSTOMES: ECHINODERMATA – CHORDATA)
PHYLUM ECHINODERMATA
 They begin their lives as free swimming bilaterally symmetrical larvae but as adults they have
radially symmetrical bodies.
 Adult echinoderms lack head, brain and segmentation.
 All marine; bottom dwellers.
 The body is covered over by a delicate epidermis stretched over a firm endoskeleton of fixed or
movable calcareous plates with spines.
 These thousand of tube feet are a part of a unique water vascular system which is also a
characteristic of echinodermata.
 Circulatory system lost in many; if present it is closed type.
 Deutrostomes: development is indirect passing usually though a bipinnaria larval stage.
 On the basis of larval development, Echinoderms are thought to be the relative of chordates.
PHYLUM CHORDATA
 All chordates show all or at least any one of the fundamental characters i.e. Notochord, Hollow
dorsal tubular nerve cord and Pharyngeal gill slits.
 Chordates in general are bilaterally symmetrical, triploblastic, deuterostome animals having a
complete digestive tract.
 Protochordates or Acraniates are those in which brain box is absent. In this group of chordates
notochord does not transform into vertebral column.
 Urochordates are also called Tunicata because their body is enclosed in a sac called Tunic
(Exoskeleton).
 They are all marine and sessile.
 The tunic is provided with two openings an incurrent or buccal siphon and an excurrent or Atrial
siphon.
 Cephalochordata is a small group and includes Branchiostoma, which is commonly called
Amphioxus. It is a small marine animal with its both ends pointed. They are the olnly chordates who
exhibit basic chordate characters in both embryonic as well as adult stages.
 In Acraniata or Vertebrata, brain is protected inside a skeletal brain box called cranium.
 Agnatha are also commonly called cyclostomes. They lack the jaw, so often known as Jawless
fishes. They are without scales or paired fins. They have also rounded suctorial mouth (cyclostomes)
with many rings of teeth.
 Lamprey and Hag fish are parasites.
SUPER CLASS PISCES
 The study o fish is called Ichthylogy.
 A fish is an aquatic gill breathing gnathostomates whose streamlined body is provided with
paired fins and covered over by dermal scales (exoskeleton).
 Anamniotes, Poikilothermic (ectothermic).
 Chondrichthyes (cartilaginous fish) also called class Elasmobranchi comprises of marine
fishes whose endoskeleton is made up of cartilages while their skin contains an enormous
number of tiny sharp enamel coated denticles called Placoid scales (exoskeleton).
 They have many usually exposed gill slits.
 Tail fin is heterocercal.
 Mouth is ventral.
 Swim bladder is absent.
 Osteichthyes (bony fishes) are also called Teleostomi.
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 They are marine as well as fresh water fishes in which mouth opening is present at the
anterior tip.
 The endoskeleton in these fishes is made of bones as well as cartilages and the exoskeleton is
made of thin bony plates which are called cycloid or ctenoid scales.
 Gills are covered over on each side by bony plates (a gill cover) called operculum.
 Tail fin is usually homocercal or Diphycerca l.
SUPER CLASS TETRAPODA
 This is the group of vertebrates which have developed two pairs of pentadactyl limbs.
CLASS AMPHIBIA
 Early stages must live in water, the adults can live in water as well as on land.
 This is the only group of vertebrates which lacks any sort of exoskeleton.
 Respire through gills (in larval stage), lungs and the lining of buccal cavity (in adult stage).
 Amphibians are poikilothermic (ectothermic) vertebrates. To avoid extremes of temperature they
undergo hibernation in winter by burying themselves in the mud to avoid low temperature of the
environment. In hot summers they do so again the process is called aestivation.
 They are said to be unsuccessful land vertebrates.
 Anamniote.
CLASS REPTILIA
 Reptilia have dry skin which is covered over by epidermal scales (exoskeleton).
 They are terrestrial and crawl on land with the help of two pairs of limbs which are
pentadactylous and provided with horny claws.
 Reptiles are poikilothermic (cold blooded).
 Completely terrestrial.
 They lay eggs on land which are covered over by leathery shells.
 Due to the presence of a protective membrane called amnion in the eggs the three groups of higher
vertebrates.
 Reptiles, Birds and Mammals are called Amniota.
 The vertebrates without it i.e. Fishes and Amphibia are called Anamniota .
CLASS AVES
 Their study is called Ornithology.
 A bird can be defined as a feather covered bipedal flying vertebrate possessing wings.
 Endotherms or Homeotherms are the animals whose body temperature remains constant
irrespective of the temperature of the environment.
 They have a sound producing sac, the syrinx. Mouth is tooth less called beak.
 Fertilization is internal and eggs are large, amniotic and covered over by hard calcareous shells.
 Sub class Ratitae of birds includes the modern big sized flightless birds.
 Almost all the modern flying birds are included in sub class Caninatae.
CLASS MAMMALIA
 Two important mammalian characters which distinguish them from other vertebrates are hairs
and mammary glands.
 Other important mammalian characters include the presence of a muscular transverse
partition, the diaphragm.
 Presence of seven cervical (Neck) vertebrae, and internal mode of fertilization are also among
the important mammalian characters.
 Teeth though few are thecodoent (lodged in sockets of the jaws) and heterodont (of different
shapes) being differentiated into 4 types i.e. incisors, canines, premolars and molars.
 All of them with the exception of egg laying mammals are viviparous.
 Prototheria are oviparous hence, called egg laying mammals. Like reptiles they have a cloaca
(common rectal and urinogenital opening) and also lack an external ear (Pinna) but like
mammals they possess hair and produce milk on which they nourish their young when they
hatch out of egg.
 Metatheria (Marsupials) are viviparous.
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 They give birth to live young one.
 They have an abdominal pouch, the marsupium and hence the metatherians are commonly
known s pouched mammals or marsupial mammals.
 Eutheria are viviparous placental mammals because the nourishment of the developing
embryo before birth takes place. In the uterus of mother, by a special organ, the placenta.
 The placenta is a connection between the mother and its developing young.
 Embryo receives oxygen and food from the mother’s circulation and discharges the wastes through placenta.
UNIT - 11
BIOENERGETICS
 Capturing and conversion of light energy into chemical energy (food) by the plants and its
ultimate transfer to the heterotrophic organisms for their use in metabolic activities is called
Bioenergetics
PHOTOSYNTHESIS
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Energy trapping and energy converting process
Solar Energy → Chemical Energy
Light
→
ATP
6CO2 + 12H2O
C6H12O6+ 6H2O + 6O2
PIGMENTS
 Substances that absorb visible light are called pigments
 Different pigments absorb light of different wave lengths
• Chlorophyll a
Bluish green
C55H72O5N4Mg
• Chlorophyll b
Yellowish green
C55H70O6N4Mg
• carotenoids
Orange
• Xanthophylls
Yellow
• Pheophytin
Grey
 There are three basic classes of pigments.
 CHLOROPHYLLS are greenish pigments which contain a porphyrin ring. This is a stable
ring-shaped molecule around which electrons are free to migrate. Because the electrons move
freely, the ring has the potential to gain or lose electrons easily, and thus the potential to provide
energized electrons to other molecules. This is the fundamental process by which chlorophyll
"captures" the energy of sunlight.
 Chlorophyll "a". This is the molecule which makes photosynthesis possible, by passing its
energized electrons on to molecules which will manufacture sugars. All plants, algae, and
cyanobacteria which photosynthesize contain chlorophyll "a".
 Chlorophyll “b”, occurs only in "green algae" and in the plants.
 Chlorophyll “c” is found only in the photosynthetic members of the Chromista as well as the
dinoflagellates.
 CAROTENOIDS are usually red, orange, or yellow pigments, and include the familiar
compound carotene, which gives carrots their color.
 These compounds are composed of two small six-carbon rings connected by a "chain" of
carbon atoms. As a result, they do not dissolve in water, and must be attached to membranes
within the cell.
 CAROTENOIDS cannot transfer sunlight energy directly to the photosynthetic pathway, but
must pass their absorbed energy to chlorophyll. For this reason, they are called accessory
pigments. E.g. fucoxanthin the brown pigment which colors kelps and other brown algae as well
as the diatoms.
PHYCOBILINS are water-soluble pigments, and are therefore found in the cytoplasm, or in the
stroma of the chloroplast. They occur only in Cyanobacteria and Rhodophyta.
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•
Phycobilins are not only useful to the organisms which use them for soaking up light
energy; they have also found use as research tools. Both pycocyanin and phycoerythrin
fluoresce at a particular wavelength
CHLOROPLASTS
 Have TWO membranes
– A “bi-bilayer!”
– The inner membrane is called the thylakoid.
– The thylakoid is folded and looks like stacks of coins called granum (grana singular).
– The stroma is the space surrounding the granum
PROCESS OF PHOTOSYSNTHESIS: Light Reaction & Light Independent Reaction
LIGHT REACTION (THE LIGHT REACTION)
 Light energy is trapped in the thylakoid membranes by chlorophyll and other molecules
– Photolysis of Water
– Chemiosmotic synthesis of ATPs
– Reduction of NADP to NADPH2
 Very rapid process
 The Journey of Electrons (e-)
 4 major groups of complexes are present in thylakoid membrane:
• Photosystem I
• Photosystem II
• Cytochrome b/f complex
• ATPase complex
 Mobile electron carriers PQ, PC and Fd transport excited electrons between the complexes
PHOTOLYSIS OF WATER:
 The PS-II reaction centre (P680) by transferring electron to primary acceptor becomes
oxidised.
 The overall process is called photo-oxidation of water.
 It requires the presence of Mn++, Ca+ and Cl- , a water oxidising enzyme and an unknown
substance Z.
 It is believed that oxygen evolves as oxygen gas.
 Electrons are accepted by PS-II reaction centre through unknown substance Z and H+
temporarily stay in the thylakoid space (loculus)
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LIGHT INDEPENDENT REACTION (DARK REACTION)
 (Calvin-Benson Cycle)
 Occurs in stroma of chloroplast
 CO2 is fixed into CH2O sugar Phosphate (Triose phosphate+DHAP) which are later converted
into carbohydrates in the stroma of chloroplast with the help of the energy of the carrier molecules
(ATP and NADPH2)
 It is slower process regulated by different enzymes
 It does not require light.
C3 Plants

Plants in which the first stable product of Light independent Reaction is 3C
(Glycerate 3 Phosphate)

C3 cycle is divided into 3 distinct phases:
– Carboxylation: CO2 is fixed into organic molecule
– Reduction: Synthesis of PGAL by reduction of organic molecule
– Regeneration: Three carbon molecules are rearranged to to form 5 Carbon RuBP
 CARBOXYLATION
Rubisco
3CO2 + 3RuBP
6G3P
 5C RuBP combines with atmospheric CO2 to produce a short lived 6C intermediate which
breaks into two molecues of glycerate 3 Phosphate (G3P)
 Account of Glycerate 3 Phosphates are formed ????
• One Benson Calvin Cycle produces 6 Glycerate 3 Phosphates from 3CO 2 molecule fixation
• So a total # of 12 Glycerate 3 Phosphates are formed by 6 CO2
• # of Carbons in 1 PGAL = 3 C
• # of Carbons in 12 PGAL=3x12=18 Carbons
REGENERATION OF RuBP
 10 G3P out of 12 are consumed in the synthesis of 6 RuBP
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Prof. Muhammad Saleem Mughal
C4 PLANTS
 This is an alternate way to fix CO2 in hot and arid climate.
 Under such conditions plants close their stomata to avoid loss of water.
 Due to the closed stomata, increasing concentration of O2 would cause
PHOTORESPIRATION to occur which is a wasteful process.
 C4 plants are those which fix CO2 into Four Carbon compound Oxaloacetate rather then 3
Carbon Glycerate 3 Phosphate
 Oxaloacetate can release CO2 for its fixation during the Calvin cycle which avoids
competition with O2
 Calvin cycle occurs in bundle sheath cells rather than mesophyll cells
 C4 examples: Grass family such as Sugar cane, etc
CAM PLANTS
 CAM plants in hot, dry climate close their stomata during day time which prevents
transpiration but also prevent CO2 from entering into leaves.
 Therefore, they open stomata at night to bring in CO2 and incorporate it into a variety of
organic acids which are stored in vacuole.
 During the day, when the light reaction supplies ATP and NADPH+H, the CO2 is released
from the organic acids for its fixation
 CAM examples: Succulent plants such as cacti, pineapple, etc
RESPIRATION:
 Energy releasing process
 A complex process of oxidation-reduction in which food is oxidized to release energy.
 Energy comes from sunlight (done by photoautotrophs), or from the oxidation of molecules.
 OXIDATION: loss of e-'s, usually with H+ as well; dehydrogenation. Also applies to partial
losses in electrons.
 REDUCTION: the gaining of e-'s, with or without H+'s.
 What is "reduced" in a reduction is the charge: Fe+++ + e- = Fe++
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 Whenever there is an oxidation, there is also a reduction.
 Not all oxidations release energy, but those involving carbon do so.
C6H12O6 + 6O2 → 6CO2 + 6H20 + 673 Kcal/mole
OXIDATIVE PHOSPHORYLATION
 Water is oxidized
 CO2 is reduced;
 in reverse, glucose is oxidized and
 O2 is reduced.
 Glucose is oxidized with the loss of electrons and oxygen is reduced by the gain of electrons.
 During this redox reaction, electrons give up energy which is used up in the synthesis of ATP
from ADP and Pi.
 This is called Oxidative Phosphorylation
ATP - LIFE’S ENERGY CURRENCY

Energy is released when ATP is hydrolyzed (broken down) to ADP.

ATP is restored from ADP and an input of energy.

ATP’s energy is used to drive endergonic (energy-requiring) reactions.
TYPES OF CELLULAR RESPIRATION: Aerobic & Anaerobic Respirations
AEROBIC RESPIRATION:
 It utilizes O2 and releases CO2, water and much energy
ANAEROBIC RESPIRATION:
 It breaks down sugar in the absence of O2
AEROBIC RESPIRATION: Glycolysis; Link reaction; Kreb’s cycle; Electron Transport System
GLYCOLSYSIS:
 Break down of glucose into 2 molecules of Pyruvate. (Pyruvic Acid)
 Common to both aerobic as well as anaerobic respirations.
 Site: Cytosol
 Oxygen is not required;
 CO2 is not released
 4ATPs & 2NADH+H are produced
KREB’S CYCLE:
 The Krebs cycle occurs two times for each glucose molecule from glycolysis, since it occurs
for each of the two molecules of acetyl coenzyme A formed by the oxidation of the two molecules
of pyruvic acid.
 For each turn of the Krebs cycle, one molecule of ATP, three molecules of NADH, and one
molecule of FADH2 (a coenzyme similar to NADH) are formed.
 Therefore, for one glucose molecule, the Krebs cycle results in the formation of two
molecules of ATP, six of NADH, and two of FADH2.
 The NADH and FADH2 then undergo the electron transport chain, resulting in the production
of more ATP.
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RESPIRATORY CHAIN OF MITOCHONDRIA
 Membrane proteins transfer e- from NADH or Succinate to O2.
 Electrons enter at complex I or II.
 Complex I, III and IV pump protons.
 Complex IV reduces O2 to H2O.
 ATP-synthase uses the proton-gradient to generate ATP from ADP & Pi.
UNIT - 12
NUTRITION
KEY POINTS
 Nutrition is the process by which the organisms obtain energy to maintain the functions of life to build the
matter and to maintain their structures.
 Nutrients are food or any substance which supplies elements and energy to the living body for its metabolic
activity.
Prof. Muhammad Saleem Mughal
 The main nutrients for living organisms are generally CO 2 and H 2 O used directly or indirectly.
 Autotrophic nutrition is the type of nutrition in which organic compounds are manufactured by living
organisms form available inorganic raw materials taken from their surroundings.
 There are two methods of autotrophic nutrition i.e. phototrophic and chemotrophic nutrition.
 All the plants, algae and some bacteria are phototrophic while some bacteria are chemotrophic.
 Heterotrophic nutrition is the type of nutrition in which organic compounds are not manufactured from
simple inorganic nutrients. Such heterotrophic organism must obtain pre-fabricated organic molecules from
their environment.
 Most bacteria, fungi and animals have heterotrophic mode of nutrition.
PLANT NUTRITION:
AUTROTROPHIC NUTRITION: (self nourishment)
 It is the type of nutrition in which organisms prepare their food from simple, inorganic
substances.
 Two types: Phototrophic; Autotrophic
PHOTOTROPHIC NUTRITION

Organisms convert LIGHT (SOLAR) ENERGY into CHEMICAL ENERGY (Food)
CHEMOTROPHIC NUTRITION
 Organisms oxidize certain inorganic substances such as ammonia, nitrates, nitrites, ferrous
ions, H2S and no of other metallic and non metallic materials .
BACTERIAL PHOTOSYNTHESIS
SULPHUR BACTERIA



Bacteriochlorophyl b is required
H2S is used instead of H2O
S is released rather than O2
2H2S+CO2→(CH2O)n+H2O+2S
PLANT PHOTOSYNTHESIS

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

Chlorophyl a, b is required to trap light
Requirements: CO2 , H2O, minerals
O2 is released
12H2S+6CO2→C6H2O6+6O2+6H2O
CHEMOTROPHIC NUTRITION
 Light is not required
 Energy is produced by the oxidation of certain inorganic substances and number of metallic
and non metallic ions
 Ammonia using Bacteria:
 NH4+ + 3O2 → 2NO2- +2H2O + 4H+ +ENERGY
 Nitrites (NO2-) using Bacteria
 2NO2- +O2 → 2NO3- + ENERGY
MINERAL NUTRTION IN PLANTS
 A mineral is an element or chemical compound that is normally crystalline and that has been
formed as a result of geological processes
 Nitrogen is also included in mineral nutrients because it is normally obtained by the plant
from soil whereas it is not a mineral element.
 Nitrogen, Phosphorus and Potassium are important minerals used in the manufacture of
Fertilizers. Often designated as N-P-K and percentages are 5-10-5
NITROGEN:
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Prof. Muhammad Saleem Mughal
 Present in the soil in the form of nitrites or ammonium salts. It is required in the biosynthesis
of Proteins, nucleic acids and many other molecules like Chlorophyll.
 Deficiency symptoms:
o
o
o
Pale leaves due to Chlorosis (loss of chlorophyll)
Purple or red veins due to development of Anthocyanin
Stunted growth, inhibition of cell division Slow rate of respiration
PHOSPHORUS:
 Present in the soil in the form of soluble phosphates. It is abundantly present in the growing
and storage organs such as fruits and seeds. Promotes healthy root growth and fruit ripening by
helping translocation of carbohydrates.
 Deficiency symptoms:
o
Purple or red veins due to development of Anthocyanin
o
Premature leaf fall
o
Stunted growth
o
Dead necrotic patches appear on leaves, petiole and fruits
o
Accumulation of carbohydrates
POTASSIUM:



Present fixed in the soil.
Plays role in opening and closing of stomata; enzyme activator
Deficiency symptoms:
o
Leaves color turns dull or bluish green
o
Irregualr chlorosis followed by development of necrotic areas at the tip and margin of
leaves.
o
Stunted growth, shortening of grains
MAGNESIUM:
 Present in the soil in water soluble, exchangeable and fixed form. It is constituent of
chlorophyll. Essential for the synthesis of fats and metabolism of carbohydrates and phosphorus.
 Deficiency symptoms:
o
Chlorosis occurs. Defoliation occurs
o
First older leaves develop symptoms of necrotic spots
SPECIAL MODE OF NUTRITION IN PLANTS
 Parasitic Plants and Saprophytic Plants
PARASITIC PLANTS:
 Depend upon other living organisms for nutrition
 Obligate/Total Parasites And Facultative/Partial Parasites
SAPROPHYTIC PLANTS


Depend upon dead organic matter for nutrition
Total Saprophytes And Partial Saprophytes
PARASITIC ANGIOSPERMS

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

Parasitic plants develop haustoria which penetrate into host tissues for absorption of nutrients.
Partial stem parasite: e.g. Loranthus on shrubs, roseaceous trees, Bauhinia and mango.
Total stem parasite: e.g. Cuscuta (amer bail) on many herbs, shrubs and trees
Partial root parasite: e.g. Sandal wood tree on many plant roots
 Total root parasite: e.g. Orobanche on the family of Cruciferae and Solanaceae
CARNIVOROUS PLANTS (INSECTIVOROUS)



Partial autotrophic and partial heterotrophic
Incapable of synthesizing nitrogenous compounds and proteins
Grow in nitrogen deficient areas
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Prof. Muhammad Saleem Mughal
 E.g. Pitcher plants; Drosera or sundew; Dionaea or venus fly trap; Aldrovanda (water fly
trap); Utricularia or bladder wort
HOLOZOIC NUTRITION
 The nutrition in which complex non-diffusible food is taken in and digested into smaller diffusible
molecules which can be absorbed and assimilated is known as holozoic nutrition.
 The holozoic nutrition is achieved by the following processes, Ingestion, Digestion, Absorption,
Assimilation and Egestion.
 It is the process by which large complex insoluble organic food substances are broken down into smaller
simple soluble molecules with the help of enzymes.
 The digestion is of two types, extra-cellular (inter-cellular) and intracellular.
 The extra-cellular digestion takes place out side the cells but within the digestive tract.
 The intracellular digestion takes place inside the cells.
 In mechanical digestion, the food is broken down into small pieces mechanically by churning or
mastication.
 The chemical digestion is the enzymatic hydrolysis.
 In sac-like digestive system, there is only a single opening which is known as the mouth.
 In tube like digestive system, the digestive cavity is separated from the body cavity. It has two openings,
mouth and anus.
 The ingestion is initial process of holozoic nutrition by which the food is taken in either directly by
phagocytosis or through the mouth.
 In metazoans, the ingestion takes place through mouth, which is a permanent opening of the digestive tract.
 It is the post digestion process in which the digested soluble food substances are absorbed directly into the
body cells or though body fluids blood and lymph.
 Assimilation is the ultimate goal of the nutrition.
 The digested food is utilized within the cells either to provide energy or materials to be incorporated into
the body.
 Egestion is elimination of the undigested food either through a temporary anus or a permanent anal opening.
NUTRITION IN AMOEBA
 Amoeba is a microphagous feeder. It engulfs the food particles. The digestion is intracellular.
 The soluble food particles are passed into the canals and finally into the surroundings cytoplasm
by micropinocytosis.
 Undigested food is egested by exocytosis.
NUTRITION IN HYDRA
 It is a macrophagous feeder and feeds upon small aquatic animals.
 The mouth opens into the body cavity (coelenteron) bounded the endoderm having glandular
and flagellated musculoepithelial cells.
 Thus the digestion in Hydra is extra-cellular as well as intracellular.
NUTRITION IN PLANARIA
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
It is carnivore and feeds upon small worms, crustanceans, snails and dead animals debris.
The prey gets entangled in the slimy secretion produced by the mucous glands.
The intestine which consists of three branches an anterior and two lateral.
Anus is absent and the undigested food is thrown out directly by the mouth.
Thus the digestive system is sac type.
The much branched intestine is a means of increasing the surface area for digestion absorption
and distribution of food.
 Digestion is both extra-cellular as well as intracellular.
NITRITION IN COCKRAOCH
 Cockroaches are omnivore.
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Prof. Muhammad Saleem Mughal
 The alimentary canal is complete and is differentiated into fore-gut (stomodaeum), mid-gut
(mesentron) and hind gut (proctodaeum).
 The mouth lies at the base of the pre-oral cavity which is bounded by the mouth parts labrum
(upper lip), labium (lower lip), mandibles (jaws) and maxillae (feeding appendages).
 A pair of salivary glands is found in the oral cavity. The saliva contains amylase which acts
upon the carbohydrates.
 The tubular pharynx dilates into a large thin walled pear shaped crop which opens into a small
rounded thick walled gizzard lined by cuticle in the form of teeth.
 This partition from pre-oral cavity to gizzard is known as fore gut or stomodaeum.
 The mid gut is a narrow tubular portion having eight hepatic caeca.
 They are lined by glandular cells which secrete enzymes.
 The enzymes produced by the mid gut and hepatic caeca flow back into the crop where proteins
and fats are digested.
 The digested food forms a bolus which gets enclosed in a thin chitinous tube secreted by the
gizzard.
 It is permeable to enzymes and the digested food.
 The hind gut has a cuticular ectodermal lining.
 It has a short tubular ileum, a long coiled colon and a broad rectum opening out through the
anus.
 The rectum absorbs and conserves the much needed water from the undigested food before
expelling out the feces.
HUMAN DIGESTIVE SYSTEM
 It consists of alimentary canal and digestive glands.
 The gut begins with mouth and buccal / oral cavity which is followed by the pharynx,
oesophagus, stomach, small intestine and large intestine.
 The mouth opens into the oral cavity.
ORAL CAVITY
 Both the jaws bear teeth which are used to masticate food into smaller pieces, resulting in
mechanical digestion which increases the surface area of food for the action of enzymes.
 Humans have two sets of teeth (diphydont), one set is deciduous or milk teeth (number = 10/10)
which appear first but are replaced by the permanent teeth (number =16/16).
 The teeth are of different shapes and sizes (heterodont) and are embedded within the gums
(thecodont).
 The milk teeth start arising at the age of six months and continue till the age of 30 months.
Molars do not appear in milk teeth.
 The permanent teeth are 32 in number consisting of 8 incisors, 4 canines, 8 premolars and 12
molars.
 The incisors are cutting and biting teeth.
 The canines are pointed used for tearing and pulling flesh.
 The molar and premolars are the grinders and are specialized for crushing and grinding the
food.
 The tongue has taste buds and tongue papillae.
 The oral cavity has three pairs of salivary glands.
 The parotid glands lie at the base of the pinnae; sublinqual glands at the base of the tongue and
the submandibular glands at the base of lower jaws.
 The saliva is a watery secretion containing 95% water, some mucus, amylase and lysozyme
enzymes.
 The salivary amylase begins the digestion of starch first to dextrins, shorter poly saccharides
and then to a disaccharide, maltose.
 Lysozyme destroys the oral cavity pathogenic bacteria.
PLAQUE AND DENTAL DISEASES
 The plaque is a mixture of bacteria and salivary materials.
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Prof. Muhammad Saleem Mughal
 Plaque also combines with certain chemicals in the saliva which becomes harden and calcified
forming deposits of calculus.
 Some of the bacteria in plaque convert sugar into acid which causes dental caries.
 Prevention of dental caries may be achieved by adding fluoride in drinking water or food.
SWALLOWING
 The swallowing is initially a voluntary action but afterwards it continues as involuntary action.
 The basic propulsive movement of the gastrointestinal tract is peristalsis.
 The usual stimulus for peristalsis is distention.
STOMACH
 The stomach is a distensible muscular bag lying below the diaphragm on the left side of the
abdominal cavity.
 It performs three functions; storage of food, mechanical digestion by peristalsis and the
chemical digestion of food by enzymes which is reduced to a creamy paste called chyme.
 The stomach has three regions; anterior cardiac region having mucous glands, middle region
fundus, which is the main part and has gastric glands and a posterior region pyloric region.
 Goblet cells secrete mucus, zymogen cells secrete pepsinogen and oxyntic cells secrete
hydrochloric acid. The collective secretion is known as gastric juice.
 The HCl softens the food, kills the bacteria, activates the inactive enzyme pepsinogen into
pepsin which acts upon proteins and convert them into short chain polypeptides (peptones) and
also breaks nucleoproteins into nucleic acids and proteins.
 In infants another proteolytic enzyme rennin is secreted which curdles the milk and converts
soluble milk proteins (caseinogen) into insoluble proteins (casein) in the presence of calcium
ions.
 The thick mucous coating prevents the internal lining of the stomach by the action of HCl.
SMALL INTESTINE
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The stomach opens into duodenum through pyloric sphincter or pylorus which acts as a value.
It is about 6 meter long and 2.5 cm wide.
There are three division of small intestine; duodenum, jejunum and ileum.
Duodenum is about 30cm long and runs parallel to the stomach. It receives a common bile duct
and a pancreatic duct opening by a common aperture.
Bile is the yellow in colour but on oxposure to air it changes to green.
It contains water, bile salts and bile pigments but no enzyme.
The bile salts (sodium bicarbonate) neutralize the acid of the gastric juice and make the chyme
alkaline.
The other salts emulsify the fats into small fat globules.
The bile pigments billirubin (red) and billiverdin (green) are excretory products formed by the
breakdown by haemoglobin of worn out R.B.Cs in the liver.
Pancreatic juice is secreted by the pancreas under stimulation of another hormone secretin
produced by the duodenum. Secretin is produced under the stimulus of HCl carried with chyme.
The pancreatic juice is a watery, colourless alkaline fluid having four enzymes trypsin
(protease), chymotrypsin (protease), amylase and lipase.
Trypsin is secreted as an inactive precursor trypsingogen which is activated by an enzyme
enterokinase produced by the duodenum. The trypsin acts upon the polypeptides and proteins
and converts them into polypeptides.
Chymotrypsin converts casein (milk protein) into short chain amino acids.
Amylase converts starch and glycogen into maltose and lipase converts emulsified fats into
fatty acids and glycerol which are the soluble end products of fat.
The digestion of fat is completed in the duodenum.
Duodenum passes into jejunum which is about 2.4 meters long.
The digestion of food is completed within the jejunum by a number of intestinal enzymes such
as maltase, sucrase, lactase, peptidase (exopeptidase and endopeptidase) and nucleotidase.
Jejunum passes into ileum which is about 3.6 meters long.
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Prof. Muhammad Saleem Mughal
 The inner wall of the small intestine contains circular folds with finger like microscopic
projections called villi whose walls are richly supplied with blood capillaries and lymph vessels
called lacteals.
 Folds and villi increase the absorptive surface area.
 Both monosaccharides and amino acids are absorbed into the blood capillaries either by
diffusion or active transport, while the fatty acids and glycerol enter the epithelial cells of the
villi.
LARGE INTESTINE
 The large intestine consists of a short caecum bearing appendix, colon and rectum terminating
at the anus.
 It has a large diameter about 6.5cm.
 Vermiform appendix is a vestigial organ.
 Inorganic salts, vitamins and water are absorbed in the colon.
 The undigested and unabsorbed food material passes down into the colon and rectum where
water and inorganic nutrients are absorbed while some metabolic wastes and inorganic
substance notably calcium excess in the body are excreted as salts along with the faeces.
 Many symbiotic bacteria present in the large intestine synthesize amino acids and some
vitamins especially vitamin K which are absorbed into the blood stream.
 The external opening of the anal canal is known as anus.
 Two sphincters surround the anus an internal one of the smooth muscle, under the control of
the autonomic nervous system and an outer one of striated muscle controlled by the voluntary
nervous system.
LIVER
 Liver is the largest gland as well as the largest organ of the body.
 A pear shaped gall bladder lies on the under surface of the liver. It stores bile which is secreted
by the liver cells.
 The bile is collected by two hepatic ducts which join the cystic duct coming from the gall
bladder forming a common bile duct which joins the pancreatic duct and opens into duodenum.
 Liver is a metabolic factory, detoxification center and storage organ.
 The liver also processes fatty acids and stores the products as ketone bodies which later are
released as nutrients for active muscles.
 Liver stores vitamins and produce necessary substances for coagulation of blood.
 It excretes out the bile pigments and other waste products.
 It converts glucose into glycogen for storage.
SOME DISORDERS OF G.I.T.
 Diarrhoea or loose motions results from rapid movement of faecal matter though the large
intestine.
 Entritis is caused by a virus or by a bacterium in the intestinal tract.
 Sometimes cholera may cause diarrhea causing extreme quantities of bicarbonate ions to be
secreted in the intestinal tract.
 Dysentery is an acute inflammation of the large intestine characterized by diarrhea with blood
and mucus in the stool. It is caused either by bacillary or amoebic infection.
 Constipation means slow movement of faeces through the large intestine.
 Piles are also known as haemorrhoids. These are dilated veins occurring in relation to the anus.
The most common cause of piles is the constipation.
 Dyspepsia is commonly known as epigatric discomfort following meals.
 A peptic ulcer is a damaged area of the mucosa caused by the digestive action of gastric juice.
 Food poisoning or gastro enteritis can be due to many causes like the infection by virus,
bacteria, protozoa or non infective by some allergy. Salmonella species are very common
causes of food poisoning. The domestic fowl is the commonest source of infection.
 When an organism is deficient in or receives excess of one or more nutrients over a long period
of time is said to have malnutrition.
 Obesity may be defined as condition in which there is an excessive amount of body fat.
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Prof. Muhammad Saleem Mughal
 Over weight is associated with an increased rate of mortality at all ages.
 Anorexia nervosa is loss of appetite for food, a psychological condition usually seen in girls
and young women.
 The symptoms of bulimia nervosa are recurrent bouts of binge eating, lack of self control over
eating during binges.
PARASITIC NUTRITION
 Parasitism is an association between two living organisms of different species in which one
partner is benefited and the other is at loss.
 The benefited partner is known as parasite and the partner at loss is called the host.
 Parasites which live on the outer surface of the host are called ectoparasties. Those live within
a host are endoparasites.
 The parasites may be obligatory when they are total parasites and live parasitically permanently
within the host. The facultative parasites live within the host and after the death of the host
continue to feed saprotrophically on the dead body.
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Prof. Muhammad Saleem Mughal
UNIT - 13
GASEOUS EXCHANGE
KEY POINTS
 Respiration is complex process of oxidation reduction in which food is oxidized to release
energy.
 In addition to the process of respiration, autotrophs like plants perform gaseous exchange for
the process of photosynthesis.
 Efficient gas exchange depends upon following factors, maintenance of diffusion gradient,
large surface area in relation to the volume of organism and presence of moist membrane or
respiratory surface for exchange of gases.
 The source of oxygen called respiratory media for aquatic and terrestrial organisms are water
and air, respectively.
 The latter is the main source of oxygen on earth which contains about 21% oxygen.
 Same volume of water when fully saturated with oxygen contains about 5% oxygen.
GASEOUS EXCHANGE IN PLANTS
 All plants exchange gases for respiration as well as photosynthesis.
 In higher land plants gas exchange through entire surface of leaves and stem is prevented due
to external, waxy covering called cuticle. It is an adaptation to avoid excessive evaporation of
water.
 The cutilarized epidermis of leaves has numerous pores called stomata (singular stoma) for the
exchange of gases as well as evaporation of water.
 Each stoma is formed by two modified epidermal bean shaped guard cells.
 Unlike other epidermal cells, guard cells bear chloroplast with thicker inner and thinner outer
walls.
 Stomata can be opened or closed depending upon the turgidity of guard cells.
 In woody stems epidermis is replaced by impervious layer of closely packed cork cells that
hamper the diffusion of gases through it. But the problem is overcome by numerous lenticels
which are localized regions of loosely arranged cells with intercellular air spaces between them.
 Through lenticels respiratory gases can move freely in and out of stem.
PHOTORESPIRATION
 It is metabolic process that occurs commonly in plants like wheat, rice, sugar cane, etc. Such
plants are termed biochemically as C 3 plants.
 It occurs during hot and dry days.
 In this process C 3 plants consume oxygen and release carbon dioxide during daytime so it is
termed as photorespiration.
 The photorespiration is an oxidation process similar to respiration in which oxygen is consumed
and carbon dioxide is released but unlike respiration it does not produce any ATP so from the
energy point of view, it is a useless and wasteful process.
GASEOUS EXCHANGE IN ANIMALS
 Respiratory surface of animals bear following properties; permeable, large surface area in
relation to volume, wet and thin.
 Earthworm uses its wet skin as respiratory surface. In order to keep the skin moist, earthworm
has to live in damp soil. The moisture is absorbed by mucous secreted from the goblet glands
in the skin of earth worm.
 Cockroach has evolved a special type of invaginated respiratory system called tracheal system.
 The tracheal system consists of number of internal tubes called tracheae with one side open
outside the body through minute slit like pores known as spiracles.
 Both the tracheoles are lines internally by thin cuticle.
 There are ten pairs of spiracles on lateral sides of the cockroach; two lie in the thoracic segments
while eight in the first abdominal segments.
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 Tracheoles finally end as blind fluid filled fine branches which are attached with the cells of
the tissues.
 The removal of carbon dioxide from the cells of the body is largely dependent upon plasma of
the blood which takes up carbon dioxide for its ultimate removal through the body surface via
the cuticle.
RESPIRATORY SYSTEM OF FISH
 Respiratory organs in fish are called gills.
 Each gill is a highly vascularized structure.
 It is composed of two rows of hundreds of filaments which are arranged in V-shape and are
supported by a cartilage or a long curved bone, the gill bar or gill arch.
 Each filament is folded to form numerous plate-like lamellae which greatly increase the surface
area of the gill.
 In bony fishes, ventilation is brought about by the combined effect of mouth and opercula (sing
operculum).
 Gas exchange is also facilitated in gills due to counter current flow of water and blood.
RESPIRATORY ORGANS OF FROG
 Frog has evolved vascularized paired out growth from the lower part of pharynx known as
lungs.
 The inner surface of alveoli is single cell layer and attached with blood capillaries.
 Alveoli are the site of exchange of gases.
 In frog ventilation in a single two way path.
 Frog uses positive pressure to move air in and out of lungs.
 This type of ventilation does not allow the lungs to be completely emptied or refilled by air
hence termed as incomplete ventilation.
 The exchange of gases on land through lungs is termed as pulmonary respiration. The other
types of gaseous exchange in frog are cutaneous respiration (through skin) and
buccopharyngeal respiration.
RESPIRATORY SYSTEM OF BIRD
 The lungs of a bird are internally sub divided into numerous small highly vascularized, thin
membranous channels called parabronchi.
 These channels are responsible for continuous flow of air in one direction.
 In addition to a pair of lungs a bird has 8 to 9 thin walled, non-muscular, non vascular, air sacs.
 The air sacs work as bellows that ensure the unidirectional flow of air or complete ventilation.
 Thus a bird must take two breaths to move air completely through the system of air sacs and
lungs.
RESPIRATORY SYSTEM OF MAN
 The respiratory system of man consists of paired lungs and the air passage ways.
 The walls of thoracic cavity are formed of inter costal muscles which are attached with a bony
cage formed by 12 pairs of ribs, vertebral column and sternum bone.
 Nasal cavity is lined internally by vascularized, ciliated epithelium containing mucous secreting
cells.
 Its internal lining is ciliated and bears mucus secreting goblets cells. Due to mucus and upward
beating of cilia any residues of dust and germs are always pushed outside the trachea into the
oesophagus through pharynx.
 The right lung is partitioned into three lobes while the left lung into two lobes.
 Each lung is enclosed by two thin membranes known as pleural membranes.
 Within the pleural membranes, there is a fluid filled narrow cavity called pleural cavity. This
fluid acts as a lubricant.
 The alveoli are considered as the respiratory surfaces of lung.
 A single alveolus is composed of single layer of epithelial cells with slightly larger diameter
than the blood capillary.
 The internal area of an alveolus is provided with a thin layer of fluid containing surfactant. It
reduces the internal surface tension to prevent it from collapsing during gas exchange.
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 Breathing is the process of taking in (inspiration/inhalation) and giving out of air
(expiration/exhalation) from the atmosphere up to the respiratory surface and vice versa.
 In man including other mammals, breathing is termed as negative pressure breathing. In this
kind of breathing air is drawn into the lungs due to negative pressure (decrease in pressure in
thoracic cavity in relation to atmospheric pressure).
 Inspiration or the process of taking in of air is energy consuming process.
 Expiration or the process of giving out of air is just reverse of inspiration. It is a passive process
which takes place due to increase pressure in thoracic cavity as well as lungs.
 Mostly rate of breathing is controlled automatically. This is termed as involuntary control. This
automatic control is maintained by coordination of respiratory and cardiovascular systems.
 It has been found that increased concentrations of carbon dioxide and H + in blood are the basic
stimuli to increase the rate of breathing.
 Their concentrations are monitored by chemoreceptors known as aortic and carotid bodies
situated in aorta and carotid arteries, respectively.
DISORDERS OF RESPIRATORY TRACT
 Lung cancer is usually a consequence of smoking either actively or passively.
 Emphysema is a degenerative disease in which alveoli gradually deteriorate.
 It happens when some toxic substance such toxic substances the elasticity of the lungs
decreases.
 Asthma is another respiratory tract disorder in which there are recurrent attacks of
breathlessness characteristically accompanied by wheezing when breathing out.
 Tuberculosis is an infectious disease of lungs. It is caused by a bacterium called Mycobacterium
tuberculosis, commonly known as T.B was once major killer diseases of human.
TRANSPORT OF GASES IN MAN
 This deoxygenated blood is dark maroon in color and appears bluish through the skin.
 Oxygenated blood is bright red in color.
 Many factors, concentration gradient, presence of any competitor such as carbon mono oxide,
moisture, surfactant, influence this transport of respiratory gases across the alveolar wall.
 The total average lung capacity of adult human being is about 5 liters of air.
 During normal breathing, a person takes in and gives out air approximately half of a liter (450
cm 3 to 500 cm 3 ). This is called tidal volume. It is only about 10% of the total capacity of lung.
 With an extra deep breath the maximum volume of air inspired and expired called vital capacity
averages about 4 liters.
 The remaining volume approximately 1 liter of air remained in the lungs is termed as residual
volume.
 Haemoglobin, an iron containing protein is a respiratory pigment present in the red blood
corpuscles of vertebrates.
 Each haemoglobin molecule has 4 iron containing groups called heme.
 It is the iron which reversibly binds with oxygen.
 Due to Hb, blood could carries 70 times more oxygen than plasma.
 Hb binds to oxygen to form a loose compound called oxyhaemoglobin.
 Myoglobin found in the muscles can bind to oxygen more tightly than haemoglobin. It gives
red colour to muscles.
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Prof. Muhammad Saleem Mughal
48
UNIT - 14
TRANSPORT
TRANSPORT IN PLANTS:
 Three Levels of Transport
i) Water, gas and solutes move in and across cell membrane,
ii) SHORT DISTANCE TRANSPORT: Loading of food from photosynthetic cells into sieve
tubes,
iii) LONG DISTANCE TRANSPORT: Conduction of wate with dissolved minerals and food
along the whole plant through xylem and phloem
 Methods of Transport Across Membrane
 Diffusion; Osmosis; Facilitated Diffusion; Active Transport; Imbibition
DIFFUSION:
 The movement of substances from their higher concentration to lower concentration is called
diffusion or Passive Transport. However, even after the equilibrium, there is movement of
substances but in a balanced condition.
OSMOSIS:
 The movement of water molecules from the region of their higher concentration towards
lower concentration through semipermeable membrane
Tonicity is a relative term
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Hypotonic Solution: One solution has a lower concentration of solute than another.
Hypertonic Solution: one solution has a higher concentration of solute than another.
 Isotonic Solution: both solutions have same concentrations of solute.
PLASMOLYSIS:
 Shrinkage of Protoplasm from cell wall due to the exsomosis of water under the influence of
Hypotonic solution is called Plasmolysis.
 Incipient Plasmolysis: When the cytoplasm just begin to separate from the cell wall
TURGIDITY:
 The condition when the cell is fully stretched due to continous endosmosis of water under the
influence of Hypotonic solution.
TURGOR PRESSURE:

The hydrostatic pressure developed by continuous movement of water inside the cell.
IMBIBITION
 Adsorption of water and swelling up of hydrophilic substances (e.g. starch, gum, protoplasm,
cellulose, etc)
 E.g. wrapping up of wooden framework during rainy season, swelling up of seeds, etc
WATER STATUS IN PLANTS
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Water is constantly taken up by the roots and lost to the atmosphere in gaseous form.
The uptake of water helps in bringing in minerals
It helps in movement of various substances within plants
It provides medium to bring about biochemical activites
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WATER POTENTIAL
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The free energy of water or its Chemical potential

The difference between free energy of water molecules in pure water and energy of
water in any other system

It is symbolized as φ (psi) and expressed in pressure unit such as megapascals
(1MPa=9.87 atmosphere)

It is a relative quantity and depends upon concentration, pressure and gravity
Prof. Muhammad Saleem Mughal
φ
= φ0 +ƒ(concentration) + ƒ(Pressure)+ƒ(Gravity)
Pure water has highest water potential and its value = 0 MPa
Addition of solutes lowers water potential so its water potential is always a negative
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term
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Water Potential determines the direction of movement of water molecules across cell
membrane
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Thus the net movement of water molecules takes place from higher wp to lower wp
across plasma membrane
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Amazingly, its is said to be the tendency to lose water since higher wp means higher
tendency of losing water.
Osmotic Potential or Solute Potential
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Osmotic Pressure (Pressure Potential): The pressure exerted upon a solution to
prevent the passage of solvent molecule into it when the solvent and solution are separated by
a differentially permeable membrane. Thus it prevents osmosis
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Osmotic Potential (Solute Potential): A measure of the tendency of a solution to
take up water when separated from pure water by a selectively permeable membrane.
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The concentration of solute particles in a solution is called solute potential
HOW WATER & MINERALS ARE TAKEN UP BY ROOTS?
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Most of the absorption takes place near root tips
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Water flow path
Root hairs → epidermal cells→ cortex endodermis → Pericycle → Xylem
Since it is in radial direction, it is also called as Lateral Transport.
Three pathways are postulated
1. Vacuolar Pathway: From cell to cell
2. Symplast: Through plasmodesmata of cell wall, the sap is taken by cells whose cytoplasm
is in direct contact with each other
3. Apoplast: Through hydrophilic cell walls, i.e. extracellular pathway
ASCENT OF SAP
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Upward movement of water and minerals from roots to the leaves against the gravity
Path of Sap: XYLEM
o Tracheids: Smaller, irregular, tubular dead lignified cells with tapering ends. In fern
and angiosperms there is only tracheids.
o Vessels: Thick walled tube like structures with lignified wall which are perforated by
pits; much faster rate of flow than tracheids.
 Upward movement of water and minerals from roots to the leaves against the gravity
MECHANISM OF ASCENT OF SAP:

Ascent of sap takes place at the rate of about 15m/hour
i)
Push from below – Root Pressure: Continuous active accumulation of ions in roots
causes water to bring inside. Even if the leaves are removed, the sap ascends and
exudes from the cut ends of stem. Root pressure caused Exudation or Guttation
through hydathodes.
ii)
Pull from above – Transpiration Pull: Loss of water from aerial parts in gaseous
form generates pulling force. Also the adhesion and cohesion properties of water
molecules brings water molecules in the form of chain.
 Ascent of Sap is solar powered.
TRANSPIRATION
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
The loss of water in the form of vapours from the aerial part of plants
About 98-99% is lost as transpiration
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Prof. Muhammad Saleem Mughal

Sites: Stomata, Cuticle and Lenticels

Stomatal Transpiration: Most of the transpiration is this type. It takes place through
stomata present as microscopic openings in the epidermis of leaves.

Two processes involved: evaporation & diffusion
Factors affecting Transpiration

Light; Temperature; Wind; Humidity; Soil water
TRANSLOCATION

The movement of photoassimilates and other organic materials from leaves to other
parts of plant is called Translocation

It occurs through Phloem from source to sink

It is mainly explained by Ernst Mϋnch in 1930

Pressure Flow Hypothesis: Flow of solution in the sieve elements is driven by a
pressure gradient produced due to differences in osmotic pressure between sources and sinks.

The pressure gradient is produced due to phloem loading and unloading at the source
and sink, respectively
TRANSPORT IN ANIMALS
 Hydra possesses a large surface area to volume ratio.
 The gaseous exchange takes place by direct diffusion across the general body surface.
 Planaria posseses an extensively branched intestine.
CIRCULATORY SYSTEM
 The purpose of a circulatory system is to provide rapid mass flow of materials from one place
of the body of the other place covering sufficient distances which cannot be easily covered by
diffusion.
 The characteristics of circulatory system are as follow:
 The blood is pumped by a contractile device around the body which may be a 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.
 The blood circulatory system is basically of two types (open type and closed type).
 The open type of circulatory system is found in Arthropods, Molluscs and Tunicates.
 The blood circulates within the open body sinuses and bathes the surrounding tissue.
 These blood sinuses are collectively known as haemocoel. Since there is no distinction
between blood and interstitial fluid so the general body fluid is more correctly known as
haemolymph.
 In insects gaseous exchange takes place through the tracheal system.
 The closed type circulatory system is more commonly found in annelid, echninoderms
cephalopods and vertebrates.
 The blood circulates through closed blood vessels and is distinct from the interstitial fluid. It
does not come out at any place in direct contact with the surrounding tissues.
 Animals with closed circulatory system are generally larger and often more active than those
with open system.
EVOLUTION OF HEART IN VERTEBRATES
 The heart of fish is two chambered consisting of an atrium and a ventricle.
 In amphibians and reptiles the heart consists of three chambers; two atria and one ventricle.
 The oxygenated blood from the lungs is returned to the left atrium through the pulmonary
veins whereas the deoxygenated blood from the body is passed to the right atrium via sinus
venosus by the anterior and posterior vena cava.
 Since the oxygenated and deoxygenated bloods are mixed with each other, the circulation is
known as incomplete double circulation.
 In birds and mammals, the heart is four chambered with two atria and two ventricles.
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Prof. Muhammad Saleem Mughal
 In them, the blood circulates through the heart twice.
 Thus it is known as complete double circulation.
 Birds and mammals are endotherms hence need more oxygen to release more heat energy.
TRANSPORT IN MAN
BLOOD
 Blood is a viscous red fluid connective tissue comprising colourless plasma in which the
blood corpuscles float.
 Plasma constitutes about 55% of the blood.
 The water is most abundant component and forms 90% of plasma.
 The dissolved substances are only 10%.
 There are the blood cells which from the remaining 45% of the blood. They are of two types.
 Red blood corpuscles (Erythrocytes) are biconcave, non-nucleated, circular, plate like cells.
Their average diameter is 7-8um.
 They contain a respiratory pigment, haemoglobin.
 The R.B.Cs are formed in bone marrow of sternum and ribs etc and are destroyed after 120
days by phagocytosis is spleen or liver.
 The iron is retained and the rest is passed as bile pigments, billirubin and biliverdin.
 White blood corpuscles (Leucocytes) are irregular, nucleated cells, larger but less numerous
than the R.B.Cs. They are formed in bone marrow, spleen, thymus and lymph nodes.
 They have short life and are destroyed with in a few 20-30 hours.
 Neutrophils and monocytes are phagocytic whereas lymphocytes, eosinophils and basophils
produce antitoxins, histamine and heparin, respectively.
 Platelets are irregular cell fragments; they are non-nucleated produced within the bone
marrow. The help in blood clotting.
DISORDERS OF BLOOD
 Leukaemia is a malignant disorder of the haemopoietic tissues associated with increased
number of leucocytes in the blood.
 Thalassaemia is an inherited impairment of haemoglobin production.
 Failure to synthesize beta chains (Beta-thalassaemia) is the most common type.
 Heterzygotes have thalassaemia minor with mild anaemia.
 Homozygotes thalassaemia major are either unable to synthesize haemoglobin or produce
very little and after 4 months of life develop a profound hypochromic anaemia.
HEART
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It is surrounded by a double layer, pericardium.
A pericardial fluid is secreted in between the two.
Two large veins, superior and inferior vena cava enter the right atrium.
Similarly two large arteries emerge out, one from the right ventricle, called pulmonary aorta
and the other from the left ventricle called systemic aorta.
The right and left atria are separated by a vertical membranous interatrial septum.
The right atrium opens into the left ventricle by the aperture guarded by a bicuspid valve
(Mitral valve).
These valves prevent backward flow of blood and allow it to move in forward direction.
The right and left ventricles are also separated by a thick muscular inter-ventcicular septum.
The inner walls of the ventricles have papillary muscles for the attachment of delicate fibres,
chordae tendinae which are attached to the cusps of the valves.
The cavity of the left ventricle is narrower than the right ventricle because of more muscular
walls.
It is due to the fact that the right ventricle has to pump blood into the lungs only (pulmonary
circulation) while the left ventricle pumps blood to the entire body (systemic circulation).
Heart muscles contract rhythmically without external stimulation. They are myogenic.
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Prof. Muhammad Saleem Mughal
 The sequence of events which take place during the completion of one heart beat is called
cardiac cycle.
 The resting period of the heart chambers is known as diastole and the period during which
they contract is known as systole.
 A human normal heart beats 72 times per minutes at rest.
 During ventricular systole blood is forced against the closed AV-vlaves. This produces the
first heart sound LUB.
 Venticular systole is followed by ventricular diastole.
 The high pressure developed in the aorate tends to force some blood back towards the
ventricles which closes the aortae valves. This impact of the back flow against the valves
causes the second heart sound DUP.
 A defect in one or more of the valves causes a condition known as heart murmur which may
be detectable as a hissing sound.
 The stimulus for contraction of the heart originates in a specific region of the right atrium
called sino-artial node close to the point of entry of the superior vena cava.
 Thus the S-A node is known as pace maker. It is located in the right atrium below S-A node.
They are stimulated by the wave of excitement send by the S-A node.
 It is excitation travel all parts of the ventricles through two bundles of specialized muscle
fibers of the bundle of His in the ventricular septum and into the walls of the ventricle through
a network of fibers called purkinje fibers consequently the two ventricles contract.
 There is a delay of about 0.15 seconds in conduction from S-A node to A-V node permitting
atrial systole to be completed before ventricular systole begins.
 Blue babies is a lay man terminology. In medical science it is known as cyanosis.
 Cyanosis is a bluish discolouration of the skin and mucous membrane due to excessive
concentration of reduced haemoglobin in the blood.
 The most common cause of cyanosis is cyanotic heart disease.
BLOOD VESSELS
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They are two types of blood vessels; arteries and veins.
The arteries carry blood away from the heart and the veins towards the heart.
Arteries are thick walled vessels consisting of three layers.
The outer tunica externa composed of fibrous connective tissue having collagen fibres.
The middle layer tunica media has smooth muscles and has elastic fibres.
The inner tunica interna consists of squamous endothelium.
The arteries are elastic and dilate during ventricle systole but do not get ruptured.
They are pulsatile and maintain the blood pressure.
Their lumen is small and does not contain semilunar valves.
The smaller arteries are known as arterioles. They contain sphincters at their capillary ends.
The arteries carry oxygenated blood except the pulmonary arteries.
Veins are thin walled blood vessels. Their lumen is large.
Semilunar valves are present which prevent the back flow of blood.
The pressure of blood flowing through them is low and they are non-pulsatile.
The veins carry deoxygenated blood except pulmonary veins.
The veins are superficial and collapse when empty.
The capillaries are extremely narrow thin walled microscopic vessels.
Their walls consist of a singe layer of endothelium.
 It is only here that exchange by diffusion or active transport occur .
BLOOD PRESSURE & BLOOD FLOW
 Blood pressure is the hydrostatic force exerted by the blood against unit area of the vessel
walls.
 Blood pressure is determined partly by cardiac output and partly by the diameter of the
arterioles when wall of the arterioles are constricted the blood pressure rises when they are
dilated (vasodilation) the blood pressure falls.
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Prof. Muhammad Saleem Mughal
 Blood in the arteries of the average adult exerts a pressure equal to a column of mercury about
120mm high in the glass tube during systole of the ventricles and 80mm during diastole. This
is expressed as a B.P of 120/80.
 The difference between systolic and diastolic pressure is called pulse pressure.
 Although an individual capillary is much narrower but the capillary beds have an enormous
number of such capillaries. So that the total diameter of these vessels is much greater than the
arteries. For this reason the blood flows slowly in the capillaries.
LYMPHATIC SYSTEM
 A system of blind vessels (lymphatic) that drains lymph from all over the body back into the
blood stream is called lymphatic system.
 In addition to lymphatic and lymph, it consists of lymph nodes, spleen, thymus, tonsils and
some of the patches of tissues in vermiform appendix and small intestine.
 The lymph vascular system starts at capillary bed where tissue fluid (interstitial fluid)
surrounding the cells of the tissue enters the lymph capillaries.
 They lymph capillaries merge into lymph vessels which have a larger diameter.
 These vessels contain smooth muscles in their walls as well as internal valves to prevent
backward flow of lymph.
 The lymph circulates through the lymph vessels by the contraction of surrounding skeletal
muscles in one direction towards by the contraction of surrounding skeletal muscles in one
direction towards the heart.
 This intercellular or tissue fluid is formed when blood passes through the capillaries.
 The capillary walls are permeable to all components of blood except the R.B.Cs and blood
proteins.
 About 85% fluid returns into the blood at the venous end of the capillary.
 The rest 15% of the tissue fluid drains into blindly ending lymphatic capillaries as lymph
along with W.B.Cs cell debris and microorganism like bacteria are transported back to the
heart through lymphatic system.
LYMPH
 Thus lymph can be defined as a colourless body fluid that contains lymphocytes (agranular
W.B.Cs), small proteins and fats. Lymph takes fluid substances from cells of tissues and
intercellular spaces which cannot penetrate the blood capillaries.
LYMPH NODES
 Throughout the course of lymphatics lie lymph nodes through which lymph flows.
 Each node consists of a thin fibrous outer capsule and an inner mass of lymphoid tissue.
 The lymphoid tissue contains antibodies, lymphocytes and macrophages.
 These nodes act as filters that trap microorganisms and other foreign bodies in the lymph.
EDEMA
 Whenever the tissues fluid accumulates rather than being drained into the blood by the
lymphatic system tissues and body cavities become swollen. This condition is known as
edema. One of the common causes of edema is severe dietary protein deficiency.
 Another cause of edema is lymphatic obstruction which results in more and more protein
collection in the local tissue fluid hence the increased volume.
 The commonest cause of lymphatic obstruction is filariasis.
CARDIOVASCULAR DISEASES
 Diseases of heart, blood vessels and blood circulation are generally termed as cardiovascular
disorders.
 Atherosclerosis is a disease of the arterial wall (intima) which loses its elasticity.
 The narrowing is due to the formation of fatty lesions called atheromatous plaques (raised
patches) in the inner lining of the arteries.
 Unfortunately atherosclerosis produces no symptom until damage to the arteries is severe
enough to restrict blood flow.
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Prof. Muhammad Saleem Mughal
 When the main arterial pressure is greater than the upper range, accepted normality the person
is said to be hypertensive having hypertension.
 Usually a mean arterial pressure of greater than 110mm Hg under resting condition
considered to be hypertensive.
 This level normally occurs when the diastolic blood pressure is greater than 90mm Hg and
systolic pressure greater than 135-140 mm Hg.
 Hypertension is called as “Silent Killer” because the affected individuals may show no
outward symptoms until a stroke or heart attack occurs.
 The formation of blood clot (thrombus) within an intact blood vessel is initiated by
atherosclerotic plaques.
 Thrombus of the coronary artery or carotid artery may cause the death to the victim due to
heart attack (myocardial infarction) and stroke.
 In a clot dislodges and travels in the blood stream it is termed as embolus.
 Narrowing or blockage of one of the coronary arteries (which supply blood) to the heart
muscle) by a thrombus is called coronary thrombosis. It refers to the death of the part of heart
muscles characterized in most case by severe continuous chest plain. This is commonly
known as heart attack.
 Stroke implies to damage to part of the brain caused by interruption to its blood supply (either
by a thrombus or embolus) or leakage of blood outside of vessel walls.
 Damage to any one cerebral hemisphere can cause weakness or paralysis of one side of the
body called hemiplagia. Hypertension and atherosclerosis are among the most common cause.
 The heamorrhage is defined as the escape of blood from the vessels.
 Small haemorrhages are classified according to their size.
 The massive accumulation of blood within a tissue is called haematoma .
THE IMMUNE SYSTEM
 The ability of the body to resist microorganisms their toxins if any, foreign cells and
abnormal cells of the body is termed as immunity.
 Immune system combats infectious agents.
 The study of the functioning and disorders of the immune system is termed as immunology.
 Immune system is a collection of cells and proteins that work to protect the body from
potentially harmful infectious microorganisms.
 The immune system can be divided into two functional divisions; Innate immune system and
adaptive immune system.
INNATE IMMUNE SYSTEM
 Innate immune system is responsible for innate or natural immunity which is non-specific in
nature since it combats all microorganisms. It consists of physical skin (mucous membrane)
and chemical (lysozyme, gastric juice) barriers against infectious micro-organisms.
 Skin and mucous membrane with their secretions act as first line of defense.
 If some how micro-organisms are able to penetrate the outer layer of the skin or mucous
membrane, they encounter a second line of defense offered by the innate immune system. It is
also non-specific in nature and comprises of phagocytes, antimicrobial proteins and
inflammatory response.
 Another group of W.B.C., the nature killer cells (NK cells) destroy virally infected own cells
of the body. This kind of destroying the target cells is called cytotoxicity.
 Among antimicrobial proteins important are lysozyme, compliment proteins and interferons.
 Interferons 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 reaction to an injury or by the entry of microorganisms.
 In case of warm blooded animals a number of microorganisms who escape away from the
inflammatory response to infect some large part of the body, trigger fever. It is usually caused
by certain W.B.Cs that release substance called pyrogen.
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Prof. Muhammad Saleem Mughal
ADAPTIVE IMMUNE SYSTEM
 The adaptive immune system is extremely complex.
 It produces specific immune response.
 This is the third line of defense which comes into play simultaneously with the second line of
non-specific defense.
 The responses of the adaptive immune system are provided chiefly by two types of
lymphocytes called B cells and T cells.
ANTIGEN AND ANTIBODIES
 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.
HUMORAL IMMUNITY
 Immunity provided by the antibodies secreted in the circulatory system by B cells is termed as
humoral immunity.
 This antibody serves as antigenic receptor.
 Antigen antibody complex binding causes such B cells antibodies into the circulation that
help eliminate that particular antigen.
CELL MEDIATED IMMUNITY
 Cell mediated immunity is contributed by the second family of lymphocytes called T cell,
which do not secrete antibodies.
 They mediate immunity by killing infected cells and aiding in inflammation.
 This is particularly important in the defense against virus as well as some parasites.
 Several types of T cells contribute to cell mediated immunity such as helper T cells (T H ),
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Cytotoxic T cells (T C ), Suppressor T cells (T S ) and memory T cells (TM).
Like B cells, helper T cells and cytotoxic T cells have antigenic receptors called T cell
receptor (TCRs) on their plasma membrane.
Major Histo-compatibility complex (MHC) Class II molecules on the surface of macrophage
or B cells.
MHC Class I , which are found on every nucleated cells of ones own body.
Cytokines or the hormones of the immune system are protein molecules secreted by the cells
of the immune system to regulate the immune responses.
The first exposure of an antigen to the immune system elicits formation of clones effector
cells to develop specific immunity.
This response of the immune system is termed as primary immune response.
Beginning from the infection to the development of maximum effector cells takes about 5 to
10 days.
Indeed, there is always risk of re-infection with the same pathogen.
In such case the immune response is always quicker than the first one. This is known as
secondary immune response. It develops to its maximum within 3 to 5 days.
TYPES OF IMMUNITY
 Immunity acquired by own immune response is called active immunity.
 If it is a consequence of natural infection, it is said to be Natural Active immunity.
 Active immunity can be acquired artificially by vaccination. In this case it is said to be
Artificial Active Immunity. It depends upon the antibodies transported from another person or
even an animal.
 It could be Natural Passive Immunity if antibodies transferred to one person were derived
from another of the same species.
 Immunization is the process of inducing immunity as a preventive measure against certain
infectious diseases.
 The incidence of a number of diseases e.g diphtheria, measles, etc has declined dramatically
since the introduction of effective immunization programmes.
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Prof. Muhammad Saleem Mughal
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