Chapter

01 The Living World

WHAT IS LIVING?
Characteristics Of living

Non - Defining Defining

Characteristics Characteristics
Metabolism,
Growth

I
Cellular organisation
Reproduction
Consciousness

y gunny ayyyDefiningpenning gym

Self - consciousness feature of human beings

NOMENCLATURE
Obviously, nomenclature or naming is only possible when the organism is described correctly. This is identification.

International Code for Botanical Nomenclature (ICBN). International Code for Viral Nomenclature (ICVN).
International Code of Zoological Nomenclature (ICZN). International Code for Nomenclature of Bacteria (ICNB).

Binomial Nomenclature

Two components
Generic name Specific epithet

First word in a biological name represents the genus while the second component denotes the specific epithet.
First word denoting the genus starts with a capital letter while the specific epithet starts with a small letter.
Both words in a biological name, when handwritten, are separately underlined, or printed in italics to indicate
their Latin origin.
Name of the author appears after the specific epithet, i.e., at the end of the biological name and is written in an
abbreviated form, e.g., Mangifera indica Linn. It indicates that this species was first described by Linnaeus.

Taxonomy

r1 Characterisation 2 Identification Kingdom

r
In case of plants, classes with few
characters are assigned to a
3 Classification 4 Nomenclature Phylum or Division
higher category called Division.

Systema Naturae was written by Linnaeus. Class

The highest category in taxonomic
Term ‘systematics’ was also given by ‘Carolus
Order hierarchy is kingdom.
Linnaeus’.
Family
Taxonomic catergories KEEP POTS CLEAN
Each category, rank or taxon (plural-taxa) Genus OR FAMILY GETS
referred to as a unit of classification.
Species is lowest category. Species I SICK
 Common
Biological Name Family Order Class/Division Phylum Kingdom
Name

Man Home sapiens Hominidae Primata Mammalia Chordata Animalia

Housefly Musca domestica Muscidae Diptera Insecta Arthropoda Animalia

Organisms Mango Mangifera indica Anacardiaceae Sapindales Dicotyledonae Angiospermae Plantae

Wheat Triticum aestivum Poaceae Poales Monocotyledonae Angiospermae Plantae

with their Dog Canis familiaris Canidae Carnivora Mammalia Chordata Animalia

Taxonomic Cat Felis catus Felidae Carnivora Mammalia Chordata Animalia

Tiger Panthera tigris Felidae Carnivora Mammalia Chordata Animalia

Categories Lion Panthera leo Felidae Carnivora Mammalia Chordata Animalia

Leopard Panthera pardus Felidae Carnivora Mammalia Chordata Animalia

Potato Solanum tuberosum Solanaceae Polymoniales Dicotyledonae Angiospermae Plantae

Brinjal Solanum melongena Solanaceae Polymoniales Dicotyledonae Angiospermae Plantae

Makoi Solanum nigrum Solanaceae Polymoniales Dicotyledonae Angiospermae Plantae

TAXONOMICAL AIDS

I. Herbarium 2. Botanical Gardens

Herbarium is a store house of collected plant These specialised gardens have collections of
specimens that are dried, pressed and living plants for reference.
preserved on sheets.
Ex-situ conservation

The herbarium sheets carry a label providing Largest famous botanical garden of world is
information about date and place of collection, Royal Botanical Garden, Kew (London),
English, local and botanical names, family, England.
collector’s name, etc.
It serve as a quick referral system Indian Botanical Garden, Sitapur, Howrah.

National Botanical Research Institute, Lucknow

3. Museum (India).

Museums have collections of preserved plant 4. zoological Parks EXSITU CONSERVATION

and animal specimens for study and reference.
These are the places where wild animals are
Plant and animal specimens may also be kept in protected environments under human
preserved as dry specimens. care and which enable us to learn about their
food habits and behaviour.
Insects are preserved in insect boxes after
collecting, killing and pinning. All animals in a zoo are protected, as far as
possible, the conditions are similar to their
Larger animals are usually stuffed and preserved. natural habitats.
6. Flora
Museums often have collections of animals too.
Flora contains the actual account of habitat and
5. Key distribution of plants of a given area.

Key is the taxonomical aid used for identification 7. Manuals

of plants and animals based on the similarities
They are useful in providing information for
and dissimilarities.
identification of names of species found in an area.
The keys are based on the contrasting
characters generally in a pair called couplet.
8. Monographs
Each statement in the key is called a lead.
They contain information on any one taxon.
Keys are generally analytical in nature .
Chapter

02 Biological classification
Number of species 1. 7 -1.8 million

Aristotle used simple morphological characters to classify plants into trees, shrubs and herbs.
He divided animals into two groups, one which had red blood (Enaima) and those that did not (Anaima).
Two kingdom classification : Linnaeus divided all organisms into two kingdoms, Plantae & Animalia
Three kingdom classification six kingdom classification
Ernst Haeckel created a new kingdom Carl Woese
Protista, having only unicellular eukaryotes. Three domains
1. Archaea: Archaebacteria
2. Bacteria: Eubacteria
Four Kingdom Classification
3. Eukarya: Includes 4 eukaryotic
Copeland (1956). kingdoms- Plantae, Animalia, Protista
Copeland created a separate kingdom and Fungi
'Monera'

Five Kingdom classification

By R.H. Whittaker
1. Plantae, 2. Animalia, 3. Protista, 4. Monera
and 5. Fungi
I Whittaker has used 5 criteria EVE TIED
1. Reproduction 3. Phylogenetic relationships
2. Cell structure 5. Thallus organisation 4. Mode of nutrition

Characteristics of the Five Kingdoms

Five Kingdoms
Characters
u Monera Protista u Fungi Plantae Animalia

Cell type Prokaryotic Eukaryotic Eukaryotic Eukaryotic Eukaryotic

Noncellulosic
Present (with
Cell wall (Polysaccharide + Present in some Present (cellulose) Absent
chitin)
amino acid) PELLICLE
Nuclear Membrane Absent Present Present Present Present

Multicellular/ Tissue/organ/
Body organisation Cellular Cellular Tissue/organ
loose tissue organ system
Autotrophic
(chemosynthetic
and Autotrophic
Heterotrophic Heterotrophic
photosynthetic) (Photosynthetic) Autotrophic
Mode of nutrition (Saprophytic/ (Holozoic/
and and (Photosynthetic)
Parasitic) Saprophytic etc.)
Heterotrophic Heterotrophic
(Saprophytic
/parasitic)
KINGDOM MONERA (i) Bacteria
Prokaryotes. Archaebacteria & Eubacteria Coccus - Spherical

I
Bacillus - Rod-shaped
1. Archaebacteria Vibrium - Comma shaped
Live in some of the most harsh habitats Spirillum - Spiral.
Halophiles : Inhabit salty areas.
Thermoacidophiles : Inhabit hot springs/deep sea Reproduce mainly by fission
water, Under favourable conditions, they produce
Methanogens : In marshy areas and gut of ruminants spore
Archaebacteria differ from other bacteria in having a

TI
Nutrition in Bacteria
different cell wall structure or different cell
membrane structure lacksadwaffAI VITA Autotrophic Heterotrophic
ANAEROBE
2. Eubacteria Mycoplasma 1. Photoautotropic
'True bacteria' Smoky 2. Chemoautotropic
1. Saprophytic
2. Parasitic
Includes bacteria, cyanobacteria (BGA), and 3. Symbiotic

I
mycoplasma.
pp
Diseases caused by the heterotrophic bacteria
Cyanobacteria of BGA = Blue green algae are
unicellular, colonial or filamentous.
Cholera Vibrio cholerae

Typhoid Salmonella typhi Cyanobacteria have chlorophyll a similar to green

plants.
Nostoc & Anabaena are cyanobacteria that can fix
Tetanus Clostridium tetani atmospheric nitrogen in specialised cells called

Citrus canker Xanthomonas citri

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heterocysts.

Mycoplasma :
Mycoplasma are also called PPLO. Lack a cell wall,
KINGDOM PROTISTA
All single-celled eukaryotes oxygen.
I
are the smallest cells and can survive without

Chrysophytes Dinoflagellates
Includes diatoms & desmids (golden algae).

Diatoms Cell wall has stiff cellulose plates

Cell wall forms two thin overlapping shells that fit Dinoflagellates have 2 flagella : One
together as in a soap box. lies longitudinally and the other
Walls are embedded with silica transversely
Large amount of cell wall deposits is referred to as Red dinoflagellates (Gonyaulax)
diatomaceous earth. undergo such rapid multiplication

I
Uses : making the sea appear red (red tides).
In polishing, Toxins (SAXITOXIN) released by them
In filtration of oils & syrups. may even kill other marine animals
such as fishes.

E
Diatoms are the chief 'producers' of oceans.

Euglenoids:
Euglenoids possesses a protein rich layer called pellicle, instead of cell wall
They have two flagella, a short & a long one
Euglena acts as connecting link between plants and animals.
 Slime Moulds PROTOZOANS
Are saprophytic protists,
without cell walls. slime moulds Amoeboid
possess true walls.
Pseudopodia e.g. Amoeba
Protozoan
Entamoeba
Under favourable conditions,
form an aggregation called Flagellated
Flagella e.g. Trypanosoma
plasmodium that may grow & protozoan
spread over several feet. SLEEPING SICKNESS
Ciliated

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During unfavourable conditions, Cilia e.g. Paramecium
forms fruiting bodies bearing Protozoan
spores at their tips. No locomotory
Sporozoan e.g. Plasmodium
Spores are extremely resistant organ
& survive for many years. They
are dispersed by air currents.

KINGDOM FUNGI
Reproduction in Fungi
With the exception of yeasts which are
unicellular, fungi are filamentous. Vegetative Asexual Sexual
Their bodies consist of long, slender Means Reproduction Reproduction
thread-like structures called hyphae.
Network of hyphae is known as Fragmentation Conidia Oospores
mycelium. Fission Zoospore Ascospores
Some hyphae are Écontinuous tubes
filled with multinucleated cytoplasm Budding Sporangiospore Basidiospores
are called coenocytic hyphae.
Cell walls of fungi are composed of
chitin

Sexual cycle involves

Fusion of protoplasms plasmogamy. Class 1 - Phycomycetes
Fusion of two nuclei karyogamy.
Meiosis in zygote results in haploid spores. Mycelium is aseptate and
coenocytic.
In some fungi the fusion of two haploid cells immediately
results in diploid cells (2n). Asexual reproduction occurs
In other fungi (ascomycetes andÉ basidiomycetes), an through zoospores (motile),
intervening dikaryotic stage (n + n, i.e., two nuclei per cell) aplanospores (non-motile).
occurs; such a condition is called a dikaryon and the phase is Spores are endogenously
called dikaryophase of fungus. produced in sporangium.
The fungi form fruiting bodies in which reduction division
occurs, leading to formation of haploid spores. Examples : Mucor

Members of phycomycetes are found : Rhizopus : White spots seen on

1. In aquatic habitats mustard leaves are due to a
2. On decaying wood in moist and damp places parasitic fungus (Albugo).
3. As obligate parasites on plants.
Class 2 - ASCOMYCETES Class 3 -Basidiomycetes:
Known as sac-fungi ascomycetes are mostly Basidiomycetes are mushrooms, bracket fungi
multicellular, e.g., Penicillium unicellular, e.g., or puffballs.
yeast (Saccharomyces). Grow in soil, on logs and tree stumps and in
'Mycelium is branched and septate living plant bodies as parasites, e.g., rusts and
Asexual spores are conidia produced smuts. The mycelium is branched and septate.
exogenously on the special mycelium called Asexual spores are generally not found,
conidiophores. Conidia on germination produce vegetative reproduction by fragmentation is
mycelium. common.
Sexual spores are called ascospores are Sex organs are absent.
produced endogenously Basidiospores are exogenously produced on
Examples : Aspergillus, Claviceps and the basidium basidia are arranged in fruiting
Neurospora. Morels (Morchella) and truffles bodies called basidiocarps.
are edible Yeast (Saccharomyces cerevisiae) Examples : Agaricus (mushroom), Ustilago
called Baker's yeast and Brewer's yeast (smut), Puccinia (rust fungus).

Class 4 -Deuteromycetes

Imperfect fungi (sexual reproduction is absent).

Asexual spores known as conidia. The mycelium is septate and branched.
Alternaria, Colletotrichum and Trichoderma.

VIRUSES. VIROIDS & LICHENS Viroids

In 1971, T.0. Diener discovered that viroids are
Virus smaller than viruses and caused potato spindle
The viruses are non-cellular organisms that tuber disease.
are characterised by having an inert RNA of the viroid was of low molecular
crystalline structure outside the living cell. weight.
Viruses are obligate intercellular parasites.
Prions
Their protein coat called capsid is made of Prions are the infectious proteinaceous agents.
Prions lack genetic material & contains only

IF
small subunits called capsomeres.
proteins molecule.
Ivanowsky discovered virus. D.J. Ivanowsky
(1892) recognised mosaic disease of tobacco. 0 MADCOW DISEASE
M.W. Beijerinek extracted infectious living Lichens CJ JACOB DISEASE
fluid and called it as Contagium vivum Lichens (SO2 Pollution indicators)
fluidum.
W.M. Stanley (1935) showed that viruses Algae (Phycobiont) Fungi (Mycoboint)
could be crystallised and are inert outside
their specific host cell.
No virus contains both RNA and DNA. Autotrophic Heterotrophic
(i) ssRNA : TMV, HIV (Retrovirus).
TMV has a coiled RNA strand.

o
(ii) ssDNA : 7 x 174 Bacteriophage.
The genetic material is infectious.
Prepare food Absorb mineral, nutrient, H2 O
and provide shelter
Chapter

08 Cell The unit of life

Cell was discovered by Robert Hooke. Schleiden and Schwann together formulated
the cell theory.
Anton Von Leeuwenhoek first saw and
described a live cell. Rudolf Virchow (Omnis cellula-e cellula).
Matthias Schleiden examined a large Cell theory as understood today is:
number of plants. i) All living organisms are composed of cells
and products of cells.

I
Theodore Schwann studied different ii) All cells arise from pre-existing cells.
types of animal cells and reported that
cells had a thin outer layer which is Prokaryotic cells
today known as the 'plasma membrane'.
Bacteria, blue-green algae, mycoplasma and
AN OVERVIEW OF CELL PPLO (Pleuro Pneumonia like organisms).
Cell wall surrounding the cell membrane
Cytoplasm is the main arena of cellular except in mycoplasma.
activities in both the plant and animal cells.
No well defined nucleus.
Mycoplasmas, smallest cells are only
0.3μm in length while bacteria could be 3 Genetic material is basically naked.
to 5μm.
Largest isolated single cell is the egg of an Small circular DNA outside the genomic DNA
ostrich (15 cm). (Plasmids.)

Human red blood cells are about 7.0 μm No organelles, like the ones in eukaryotes,
in diameter. except for ribosomes.

E
Nerve cells are longest cells. Something unique in the form of inclusions.
RBCs are round & biconcave.

Cell Envelope and its Modifications

Three layered structure outermost Help in cell wall formation, DNA
glycocalyx followed by the cell wall and replication respiration,respiration
then the plasma membrane. Function secretion processes.
together as a single protective unit.
Those that take up the gram stain are Cyanobacteria, have other membranous
Gram positive and the others that do not extensions into the cytoplasm called

I
are called Gram negative bacteria. chromatophores which contain pigments.

Glycocalyx Could be a loose sheath Cell wall determines the shape of the
called the slime layer in some, in others cell and provides a strong structural
it may be thick and tough, called the support to cell.
capsule.
Plasma membrane is selectively-
permeable in nature.
Flagella FLAGELLIN
Mesosome formed by extensions of
Filamentous extensions from their cell wall. plasma membrane in the form of
Pili and Fimbriae are also surface structures vesicles, tubules and lamellae.
of the bacteria but do not play a role in
motility.
sonogram
Pili made of a special protein Pilin.
Fimbriae are small bristle like fibres.
Help attach the bacteria to rocks in streams
and also to the host tissues.
 Ribosomes Inclusion Bodies
15 nm by 20 nm in size made of two Reserve material are stored in the
subunits 50S and 30S units which
when present together form 70S. cytoplasm in the form of inclusion bodies.

Site of protein synthesis. Not bounded by any membrane system

Several ribosomes may attach to a Gas vacuoles are found in blue green and
single mRNA and form a chain called purple and green photosynthetic bacteria.
polyribosome or polysome.

EUKARYOTIC CELLS
Extensive compartmentalisation,
presence of membrane bound
organelles.
Organised nucleus with a nuclear
envelope. Variety of complex
locomotory and cytoskeletal
structures.
CELL MEMBRANE
Plant and animal cell are different as
the former possess cell wall, plastids Lipids are arranged in a bilayer.
and a large central vacuole which are
absent in animal cells. Polar head towards the outer sides
hydrophobic tails towards the inner part.
CELL WALL The membrane of the erythrocyte has
A non-living rigid structure forms an approximately 52 per cent protein and
40 per cent lipids.
outer covering for the plasma membrane.

Gives shape to the cell and protects the

cell from mechanical damage and Fluid Mosaic Model
infection, it also helps in cell-to-cell
interaction provides barrier to Proposed by Singer and Nicolson.
undesirable macromolecules.
Peripheral proteins lie on the surface of
Algae made of cellulose, galactans, membrane while the integral proteins
are partially or totally buried in the
carbonate, in other plants Iit consists of
mannans and minerals like calcium
membrane.
lipids can tiptopbut
cellulose, hemicellulose, pectins &
proteins. Quasi-fluid nature of lipid enables lateral
movement of proteins within the overall
ppg
bilayer.
Young plant cell, the primary wall is
capable of growth, secondary wall is
formed on the inner (towards I Fluid nature of the membrane; cell growth
formation of intercellular junctions,
membrane) side of the cell. secretion, endocytosis, cell division etc.
Middle lamella is a layer mainly of
calcium pectate which holds or glues Important functions of the plasma membrane
the different neighbouring cells is the transport of the molecules across it.
together.
Movement of water by diffusion is called
Cell wall and middle lamella may be osmosis.
traversed by plasmodesmata to
I
connect the cytoplasm of neighbouring
cells.

Endomembrane System
(i) Endoplasmic Reticulum (ER) (iii). Lysosomes

Network or reticulum of tiny tubular Formed by the process of packaging

structures scattered in the cytoplasm. in the golgi apparatus.

Divides the intracellular space into two, Rich in almost all types of hydrolytic
luminal & extra luminal compartments. enzymes optimally active at the
acidic pH.
Endoplasmic reticulum bearing ribosomes
on their surface is called rough
endoplasmic reticulum (RER). Capable of digesting the
macromolecules like carbohydrates,
In the absence of ribosomes they appear proteins, lipids and nucleic acids
smooth and are called smooth endoplasmic
reticulum (SER).
RER involved in protein synthesis and
(iv). Vacuoles
secretion. Membrane-bound space found in the
cytoplasm, bound by a single
Smooth endoplasmic reticulum, major site membrane called tonoplast.
for synthesis of lipid and steroids (lipid –
like steroidal hormones).
Vacuoles can occupy up to 90 per
cent of the volume of the cell.
(ii). Golgi Apparatus
Contains water, dissolved substances,
Camillo Golgi first observed densely sap, excretory product and other
stained reticular structures near the materials not useful for the cell.
nucleus.
Many flat, membranous disc-shaped Transport of a number of ions and
sacs/bag or cisternae of 0.5μm to other materials against concentration
1.0μm diameter. gradients into the vacuole.
Stacked parallel to each other. In Amoeba, contractile vacuole is
Concentrically arranged near the important for excretion &
nucleus with distinct convex cis or the osmoregulation.
forming face and concave trans or the
maturing face. In protists, food vacuoles are formed
by engulfing the food particles.
Function of packaging materials to be
delivered either to the intra-cellular
targets or secreted outside the cell.
(4) Mitochondria
Packed in the form of vesicles from the ER
fuse with the cis face of the golgi Absent in mammalian RBCs and
apparatus and move towards the maturing prokaryotes.
face.
Sausage-shaped or cylindrical having a
Proteins modified in the cisternae of the diameter of 0.2 -1.0 μm (average 0.5 μm)
golgi apparatus before they are released and length 1.0 – 4.1 μm
from trans face.
Double membrane-bound structure
Important site of formation of distinctly two aqueous compartments, the
glycoproteins and glycolipids. outer compartment and the inner
compartment.
Inner compartment is called the matrix.
(5) Plastids Inner membrane forms a number of
infoldings called the cristae (sing.: crista)
Found in all plant cells and in euglenoids. towards the matrix.
Bear some specific pigments, imparting Sites of aerobic respiration or Kreb's
specific colours to the plants. cycle.

Classified into chloroplasts, chromoplasts and 'Power houses' of the cell.

leucoplasts.
Single circular DNA molecule, few RNA
molecules, ribosomes (70S).
Divide by fission.
 Chloroplasts
Lens-shaped, oval, spherical, discoid or
even ribbon-like organelles having variable
length (5-10Pm) and width (2-4Pm).
1 per cell of the Chlamydomonas, 20-40
per cell in the mesophyll.
Double membrane bound., the inner
chloroplast membrane is relatively less
permeable.
Space limited by the inner membrane of
the chloroplast is called the stroma.
Number of organised flattened disc like
membranous sacs called the thylakoids,
Thylakoids are arranged in stacks like the
piles of coins called grana.
oil & fat protein

Flat membranous tubules called the

stroma lamellae connecting the

(6) Ribosomes to I thylakoids of the different grana.

Membrane of the thylakoids enclose a

Granular structures first observed as dense space called a lumen.
particles by George Palade (1953).

Composed of ribonucleic acid (RNA).

so I small, double-stranded circular DNA
molecules and ribosomes.
Eukaryotic ribosomes are 80S prokaryotic
Ribosomes of the chloroplasts are smaller
ribosomes are 70S.
(70S) than the cytoplasmic ribosomes
'S' stands for the Svedberg unit or (80S).
sedimentation coefficient.
w Mitochondria and chloroplast are semi-
Two subunits of 70S ribosome are 50S autonomous organelles because
(larger subunit) 30S (smaller subunit).
Possess their own nucleic acid (DNA
molecule).
Two subunits of 80S ribosome are 60S
(larger subunit) & 40S (smaller subunit). Can form some of the required protein.
Ribosomes are site of protein synthesis so Do not arise de novo.
they are called protein factories.
membrane similar to those of bacteria.

(7) Cytoskeleton
(8) Cilia and Flagella
Network of filamentous proteinaceous
structures present in the cytoplasm is Hair-like outgrowths of the cell membrane.
collectively referred to as the
cytoskeleton. Cilia are small structures which work like
oars.
Mechanical support, motility,
maintenance of the shape of the cell. Flagella are comparatively longer and
responsible for cell movement.
Core called the axoneme, possesses a
number of microtubules running parallel to
INTER the long axis.
DOUBLE
at
Axoneme usually has nine pairs of
doublets of radially arranged peripheral
microtubules, and a pair of centrally

g
located microtubules.
9+2 array.
Both the cilium and flagellum emerge
from centriole like structure called the
basal bodies.
 (9) Centrosome and Centrioles
Two cylindrical structures called centrioles.
They are surrounded by amorphous
pericentriolar materials.

II
Centrioles in a centrosome lie perpendicular
to each other in which each has an
organisation like the cartwheel.
Nine evenly spaced peripheral fibrils of
tubulin.
Each of the peripheral fibril (microtubule) is
a triplet. The adjacent triplets are also
linked.
The central part of the centriole is also
proteinaceous and called the hub, which is
connected with tubules of the peripheral
triplets by radial spokes made of protein.
The centrioles form spindle fibres that give
10) Microbodies rise to spindle apparatus
Membrane bound minute vesicles called
microbodies.
9140450ME PEROXISOME PITY TIME
11) Nucleus
First described by Robert Brown
Stained by the basic dyes was given
the name chromatin by flemming. 0000
Normally, there is only one nucleus structure
per cell. a
Some mature cells even lack nucleus,
e.g., erythrocytes of many mammals
and sieve tube cells of vascular
plants. These cells are enucleated or
anucleated.
Chromatin contains DNA and some basic
The interphase nucleus has highly proteins called histones some non-histone
extended and elaborate nucleoprotein proteins and also RNA.
fibres called chromatin, nuclear matrix
and one or more spherical bodies called Every chromosome essentially has a primary
nucleoli. constriction or the centromere on the sides
of which disc shaped structures called
Two parallel membranes with a space kinetochores are present.
between (10 to 50 nm ) called the
perinuclear space.
w
Nuclear envelope is interrupted by
minute pores, which are formed by
the fusion of its two membranes.
w V
Nuclear pores are the passages
through which movement of RNA and
protein molecules takes place in both
directions between the nucleus and L
the cytoplasm. W
Nucleoplasm contains nucleolus and
chromatin. a
Content of nucleolus is continuous
with the rest of the nucleoplasm it J
is not a membrane bound structure.

Nucleolus is a site for active

ribosomal RNA (r-RNA) synthesis. w
i
 E E w

Few chromosomes have non-staining secondary constrictions at a constant location. This gives the appearance
of a small fragment called the satellite.

Short arm p arm

long arm
q arm
Chapter

18 Body Fluids and

Circulation
Blood is a special connective tissue consisting of -

Plasma

Straw coloured, viscous fluid constituting 55 Plasma also contains Na+, Ca++, Mg ++,
per cent of blood. 90-92 per cent water and HCO3- Cl -, glucose, amino acids, lipids,
6 to 8 per cent proteins which include
etc.
Fibrinogens: coagulation of blood. Plasma without the clotting factors is
Globulins: defense mechanisms albumins serum.

E
osmotic balance.
Albumins: osmotic balance
Formed Elements
Constitute 45 percent of the blood.

RBC s (Erythrocytes)
most abundant. w 12-16 g of haemoglobin in 100 ml blood w

5 - 5.5 million RBCs mm -3 w Role in transport of respiratory gases. w

Formed in red bone marrow. w Life span of 120 days

Devoid of nucleus, biconcave in shape. w Destroyed in the spleen (graveyard of RBCs).

Have red coloured, iron containing
protein called haemoglobin. w
wBC s (Leucocytes) w
w
6000-8000 mm⁻³ of blood. w Monocytes: (6-8 per cent), phagocytic cells

Short lived
w Basophils: least abundant (0.5-1 per cent),
secrete histamine, serotonin, heparin,
Neutrophils, eosinophils and basophils are
involved in inflammatory reactions. w
granulocytes, lymphocytes and
monocytes are the agranulocytes. w Eosinophils (2-3 per cent) resist infections.

Neutrophils: most abundant (60-65 per Lymphocytes (20-25 per cent)

cent), kill microbes by phagocytosis. B and T lymphocytes are responsible for
w immune responses.
w
 Platelets (Thrombocytes)
produced from megakaryocytes in bone marrow.

1,500,00 - 3,500,00 platelets mm–3.

prothrombin thrombokinase Thrombin
w ABO grouping
Based on the presence or absence of two surface antigens A and B.
f
fibrinogen fibrin
Plasma contains two natural antibodies.

Blood groups and Donor Compatbility

w w
Antibodies in
Blood group Antigens of RBCs Donor’s group
Plasma

A A Anti-B or b A, O
B B Anti-A or a B, O
AB A, B nil AB, A, B, O
O Nil Anti-A, B O

'O' group individuals are 'universal donors'.

w O ABT
UD UR
'AB' individuals are 'universal recipients'.

Rh grouping w
Rh incompatibility between the Rh-ve blood
Rh antigen is observed on the surface of mother with Rh+ve blood of foetus leads
of RBCs of 80 per cent of humans to erythroblastosis foetalis.
(Rh+ve). When antigen is absent
(RH-ve).

COAGULATION OF BLOOD
Prevent excessive loss of blood. w
w w
Calcium ions play important role.

w e

e
 human circulatory system
TISSUE FLUID w Heart (mesodermally derived).

Fluid released out from capillaries is Protected by double walled pericardium.

called interstitial fluid or tissue fluid.
Two small upper chambers (atria)
Same mineral distribution as plasma.
two larger lower chambers (ventricles).

lymphatic system drains it back to veins. Tricuspid valve: between right atrium and

I
right ventricle
Lymph: colourless fluid containing Bicuspid or mitral valve: between left
specialised lymphocytes. atrium left ventricle.

NC EUSTACHIAN A Semilunar valves: openings of right and left

ventricles into pulmonary artery and aorta
VANE
CORONARY SINUS Thebasian Valves prevent backward flow.

Value

NODAL TISSUE W cardiac cycle O 8510

Specialised musculature distributed in 4 phases in a cardiac cycle:
heart.
W Joint Diastole: all four chambers are in relaxed
O Sino-atrial node (SAN): Right upper corner
of the right atrium
state.
Blood flows into ventricles.
Otsu
O Atrio - ventricular node (AVN): lower left
corner of the right atrium
W Atrial systole : SAN generates an action
potential and atria undergo contraction.
This increased the flow of blood into ventricles
Bundle of nodal fibres continues, passes
ATRIAL DIASTOLE 0.7sec
through atrio - ventricular septa, divides Ventricular systole : action potential
into a right and left bundle. conducted to ventricular side,
0.35L Ventricles contract, atria relax.

O Give rise to minute fibres throughout

ventricular musculature (Purkinje fibres).
Closure of tricuspid and bicuspid valves.
Semilunar valves open.

These fibres with right and left bundles `Ventricular diastole: ventricles relax closure of

I
bundle of His semilunar valves.
Tricuspid and bicuspid valves open.
Nodal musculature is autoexcitable. Blood moves freely to ventricles.

SAN generates maximum number of action

potentials, i.e., 70-75 min–1,

It is called the pacemaker (average 72 beats

min–1).
 Co SU X HR
This sequential event is called the cardiac Cardiac output = Stroke volume x Heart
cycle. rate.

Duration of a cardiac cycle is 0.8 seconds. During cardiac cycle two prominent sounds
are produced.
Each ventricle pumps out 70 mL blood/min First heart sound (lub): closure of the
(stroke volume). tricuspid and bicuspid valves
Second heat sound (dub): closure of the
Cardiac output: volume of blood pumped out by semilunar valves.
each ventricle per minute (5000 mL)

ELECTTROCARDIOGRAPH (ECG)

Machine (electro-cardiograph) used to

obtain an electrocardiogram (ECG).

Graphical representation of electrical

activity of heart.

Patient is connected with three electrical

leads (one to each wrist and to left
ankle)

P-wave: depolarisation of the atria

QRS complex: depolarisation of the ventricles
T-wave: (repolarisation).

Circulatory Pathways

EDT
Fishes have 2-chambered heart.

Pty
Amphibians reptiles (except crocodiles) 3-
chambered heart.

Birds and mammals 4-chambered heart.

Double Circulation
Oxygenated and deoxygenated blood received Systemic circulation: left ventricle pumps
by the left and right atria respectively passed blood into the aorta
to two separate circulatory pathways Oxygenated blood entering the aorta is
carried by capillaries to tissues from
Pulmonary circulation: Blood pumped by the where the deoxygenated blood emptied
right ventricle enters the pulmonary artery into the right atrium.
Passed on to the lungs from where the
oxygenated blood is carried by the pulmonary
veins into the left atrium
 Hepatic portal system: Unique vascular DISORDERS OF CIRCULATORY SYSTEM
connection between the digestive tract and
liver High Blood Pressure (Hypertension) w
r Special coronary system of blood vessels for Normal: 120 mm Hg systolic pressure and 80
circulation to cardiac musculature. mm Hg diastolic pressure.
If 140/90 mm Hg (140 over 90) or higher, it
Neural centre in the medulla oblangata can shows hypertension.
moderate the cardiac function through Leads to heart diseases, affects vital organs.
autonomic nervous system (ANS).

Sympathetic nerves increase heart beat,

r Coronary Artery Disease (atherosclerosis)
Deposits of calcium, fat, cholesterol and
ventricular contraction and cardiac output. fibrous tissues, makes arteries narrower.
Parasympathetic neural signals decrease the
heart beat, conduction of action potential Angina pectoris: acute chest pain when not
and cardiac output. enough oxygen is reaching the heart muscle.

Adrenaline Thyroxine p t Heart Failure: heart is not pumping blood

effectively enough

Vagal stimulation of A Cardiac Arrest: heart stops beating,

Acetylcholine I t Heart attack (Myocardial Infarction) : heart

muscle is suddenly damaged.
Chapter

20 Locomotion
and Movement
INTRODUCTION
Animals and plants exhibit a wide range of Movements result in a change of place o r location.
movements. Such voluntary movements are called locomotion.

TYPES OF MOVEMENT
Type of movement in human body MUSCLE
Mesodermal origin.

40-50 percent of the body weight have special

properties like excitability, contractility,
extensibility and elasticity.

É Made of many long, cylindrical fibres composed of

numerous fine fibrils, called myofibrils.

Muscle fibres contract (shorten) in response to

I
Locomotion require s a perfect coordinated stimulation, then relax (lengthen) & return to
activity of muscular, skeletal and neural systems. their uncontracted state.

types of muscles
Skeletal (striated) muscles Visceral (Non-striated) muscles Cardiac muscles

SKELETAL MUSCLE
Made of a number of muscle bundles or fascicles held
together by a common collagenous connective tissue
layer called fascia.

Muscle fibre is the anatomical unit of muscle.

Total number of muscle in human body - 639.

Largest muscle - Gluteus maximus

Smallest muscle – Stapedius

Longest muscle – Sartorius

 Muscle Fibre
Lined by the plasma membrane Syncitium
called sarcolemma.
Presence of a large number of
Sarcoplasmic reticulum is the parallelly arranged filaments in
store house of calcium ions. the sarcoplasm called
myofilaments or myofibrils.
I 0 A Each myofibril has alternate dark and light bands on it.

feat
1
0 O
tail
O g The portion of the myofibril between two successive 'Z' lines is
considered sarcomere.

112 I BANDIABAND t 112 IBANDA

C D
Structure of Contractile Proteins

lengthof Sarcomere t
MECHANISM OF MUSCLE CONTRACTION 1Band 1
ABAND SAME
Hzoned
Sliding filament theory which states that
W
contraction of a muscle fibre takes place by the
sliding of the thin filaments over the thick
filaments
w
Signal sent by (CNS) via a motor neuron.

Motor neuron along with the muscle fibres w

constitute a motor unit junction between a motor w
neuron and the sarcolemma of the muscle fibre is
called the neuromuscular junction or motor-end
plate.

A neural signal reaching this junction releases a

neurotransmitter (Acetylcholine) which generates
an action potential in the sarcolemma.
Increase in Ca++ level leads to the binding of calcium with a
Spreads through the muscle fibre and causes the subunit of troponin on actin filaments and thereby remove the
re lease of calcium ions into the sarcoplasm. masking of active sites for myosin.
W
Utilising the energy from ATP hydrolysis, the myosin
head now binds to the exposed active sites on actin
to form a cross bridge.

'Z' line attached to these actins are also pulled

inwards thereby causing a shortening of the
sarcomere, i.e., contraction.
w w
During shortening of the muscle, i. e. 'I' bands get s fast
reduced.'A' bands retain the length. H-zone also
t o
reduced
To
The process continues till the Ca++ ions are pumped
back to the sarcoplasmic cisternae resulting in the
masking of actin filaments. causes the return of 'Z'
lines back to their original position, i.e .,
relaxation. Tactic And
Repeated activation of the muscles can lead to the
accumulation of lactic acid due to anaerobic
breakdown of glycogen in them, causing fatigue.

SKELETAL SYSTEM w
In human beings , this system is
made up of 206 bones and a
few cartilages.

Axial skeleton comprises 80 bones

O t we

distributed along the main axis of

the body.

Thus the skull consists or 29 bones as

Cranial bones. - 8
Facial bones. - 14 In C Atlas
Hyoid bones. - 1 w
a a
Ear ossiclcs - 6 C2Axis
29
Axial skeleton (80 bones)
Vertebral column of man is made u p of 33 bones but is
consists of only 26 vertebrae because 5 sacral vertebrae
fused to for m one sacrum & 4 coccygeal vertebrae fused 1. Skull - 29 (8, 14, 1, 6)
to form one coccyx. 2. Vertebral - 26 (7, 12, 5, 1, 1)
column
26 serially arranged units called vertebrae. 3. Sternum - 1
4. Ribs - 24 (7, 3, 2) × 2
First vertebra is the atlas and it articulates 80
with the occipital condyles

Ribs
O Appendicular skeleton (126 bones)
n Fore limb (30 bones)
12 pairs of ribs . Each rib is a thin flat bone

ventrally to the sternum. I

connected dorsally to the vertebral column and
1. Fore limb - 60 (30 × 2) w 1. Humerus - 1

E
2. Hind limb - 60 (30 × 2) 2. Radius - 1
Biccphalic 3. Pectoral girdle - 04 (2 × 2) 3. Ulna - 1
4. Pelvic girdle - 02 4. Carpals - 8

O
First seven pairs of ribs are called true ribs. 126 (wrist bones)
5. Metacarpals - 5
Dorsally, attached to the thoracic Vertebrae (palm bones)
ventrally connected to the sternum with the help 6. Phalanges
of hyaline cartilage..
W (digits) - 14
30
 The 8th , 9th and 10th pair s of ribs do not articulate Hind limb (30 bones)
directly with the sternum but join t he seventh rib with

I
the help of hyaline cartilage. These are called 1. Femur (thigh bone) - 1
vertebrochondral (false) ribs. 2. Tibia - 1
3. Fibula - 1
Last 2 pairs (11th and 12th) of ribs are not connected 4. Tarsals (ankle bones) - 7
ventrally and are therefore, called floating ribs. 5. Metatarsals - 5
6. Phalanges (digits). - 14
7. Patella (cup-shaped) - 1
30

Pectoral Girdle/shoulder girdle

Consists of a clavicle and a scapula. a is a depression called the glenoid
Below the acromion

I
cavity which articulates with the head of the humerus to
Scapula is present in dorsal part of thorax w form the shoulder joint.
between the second an d the seventh ribs.

Clavicle is a long slender bone with two curvatures. This

Dorsal, triangular body of scapula called the
bone is commonly called the collar bone.
acromion. The clavicle articulates with this.

JOINTS
PELVIC GIRDLE
Two coxal bones.

Each coxal bone is formed by the fusion of

three bones - ilium, ischium and pubis.
v
At the point of fusion of the above bones
is a cavity called acetabulum to which the
thigh bone articulates.
t O
The two halves of the pelvic girdle meet
ventrally to form the pubic symphysis
containing fibrous cartilage.

DISORDERS OF MUSCULAR
AND SKELETAL SYSTEM
w
w
Myasthenia gravis : Auto immune disorder
affecting neuromuscular junction leading to a
fatigue, weakening and paralysis of skeletal w w
muscle.

MUSCULAR DYSTROPY Genetic

Tutany low ca't

Osteoporosis Estrogen I
Rheumatoid arthritis Pannu
Gouty Arthritis URICAUD
Accumulation in Joint