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Subject : Biology
Basic Terminology
Cell :- The basic structural & functional unit of
life is called cell.
Tissue :- ‘A’ group of cells performing a
particular function is called tissue.
Organ :- A group of tissue performing a
particular function is called organ.
Organ System :- A group of organs performing
a particular function is called organ system.
Eukaryotic cell :- The cell in which nucleus is
well organized as well as member bound cell
organelles are present is called Eukaryotic cell.
Prokaryotic Cell :- The cell in which nucleus is
not well organized as well as membrane bound
cell organelles are not present then it is called
procariyotic cell.
Nutrition :- The process in which nutrients are
taken inside the body is called nutrition.
Photosynthesis
Hetrotroptric
Chemosynthesis
Saprophytic Parasite Holozoid
Ectoparasite
Endoparasite :- The parasite which is present
outside the body of the host is called
ectoparasite.
Holozoic Nutrition :- The nutrition in which
organisms shows tendency towards engulfing
food material is called holozoic nutrition.
HABITAT :
Aquatic organisms :- The organisms which can
survive only in water are called as aquatic
organizations.
Amphibian :- The organisms which can survive
in water as well as on land are called
amphibians.
Terrestrial :- The organisms which can survive
in water as well as on land are called
amphibians.
NUTRITION
Autotropric
Parasitic Nutrition :- The nutrition in which an
organisms is dependent on another living
organisms for is nutrition is called parasitic
nutrition.
Ectoparasite
Autotrophic Nutrition (Self-dependent) :The nutrition in which organisms depend on
itself for nutrition is called autotrophic
nutrition.
Chemosynthetic Nutrition :The type of nutrition in which organisms
prepare its own food in presence of chemical is
called chemosynthetic Nutrition.
Photosynthetic Nutrition :- The type of
nutrition in which organisms prepare its own
food in presence of light is called
photosynthetic nutrition.
Hetrotrophic Nutrition :- The nutrition in
which organisms are depends on another
organisms is called heterotrophic nutrition.
Saprophytic Nutrition :- The nutrition in which
an organisms are dependent on the dead or
decaying matter is called as saprophytic
Nutrition.
Arboreal :- The organisms which spends most
of the life time over the trees are called arboreal
organisms.
Aerial :- The organisms which can fly in air are
called aerial originations.
Hydrophytes :- The plants which survives in
water are called hydrophytes.
Mesophytes :- The plants which survives in
moderate conditions are called mesophytes.
Xerophytes :- The plants which survives in high
temperature and low rainfall in called as
xerophytes.
Reproduction :- The process of production of
new individual from the pre-existing individuals
is called as Reproduction.
Types of Reproduction :
Haploid : A cell having single set of
chromosomes is called Haploid. It is represented
by ‘n’.
Diploid : A cell having two sets of chromosomes
is called diploid (2n)
Gamete :
gamete.
A sexually reproducing cell is called
Sextual Reproduction : The reproduction in
which hapliod male gamete unites with hapliod
female gamete to form a diploid zygole is called
as sexual reproduction.
Asexual Reproduction :- The reproduction
which does not involve union of opposite
haploid
gamete
is
called
Asexctual
Reproduction.
Vegetative propogation / Reproduction : The
formation of new plant from pre-existing plant
body’s vegetative parts is called vegetative
reproduction or vegetative propagation.
Vegetative Part : The part of the plant body
which does not produces either male or female
gamete is called vegetative part.
Reproductive part
: The part which can
produce either male or female gamete is called
Reproductive part.
Cell Division : The ability of a cell to divide into
two is called cell division.
Types of cell Division : A cell division can be
differenciated into two types as
1) Mitosis.
2) Meiosis.
 Mitosis :- A type of cell division in
which a mother cell divide into two
daughter cells is called mitosis.
 Meiosis :- A type of cell division in which
one mother cell divides into four
daughter cells with the change in
chromosome number is called meiosis.
==================
Subject : Biology.
Topic
: DIVERSITY IN ORGANISMS
1. DIVERSITY IN LIVING ORGANISMS :
Enormous variety of living organisms exist
on the earth. There are about 5-30 milion
species of plants and animals on earth. It is not
possible for a human being to remember the
characteristics of all these organisms without
their systematic arrangement.
2. SYSTEMATICS : TAXONOMY,
TAXONOMIC HIERARCHY AND BINOMIAL
NOMENCLATURE.
Systematics : “ Systematics is the scientific
study of similarities and differences among
different kinds of organisms and it also includes
their
identification,
nomenclature
and
classification.
Taxonomy : It is the branch of biology which
deals with the collection, identification of plants
and animals.
Objectives of Systematics/ Taxonomy :
i)
To know various kinds of plants on the
earth with their names, affinities,
geographical
distribution,
habit,
characteristics and their economic
importance.
ii) To have a reference system for all
organisms with which the scientists can
work.
iii) To demonstrate the manifold diversities
of organisms and their phylogenetic
(evolutionary) relationship.
iv) To ascertain nomenclature i.e, scientific
name for every organism.
Classification :
The classification is based on similarities and
dissimilarities among the organisms.
Need of Classification :
i)
ii)
iii)
iv)
The classification helps to explain
unity in diversity of the organisms.
It is gives specific and scientific
names to the organisms which are
accepted universally.
It reveals the relationships among
various group of organisms.
The classification places an organism
amongst those which have common
characteristics.
Taxonomic hierarchy [Gr. – Hierarchs = rank]
The manner of scientific grouping of different
taxonomic categories in a descending order on
the basis of their ranks or positions in
classification is called taxonomic hierarchy.
i) Taxon :- Taxon a group of living organisms
(pl. taxa) which is used to represent a concrete
unit of classification.
ii) Category :- A category is a rank of level in
the hierarchial classification of organisms.
Example :
Method of classification of China rose and
Cobra.
Category
Taxon
Taxon
Kingdom
Plantae
Animalia
Division/Phylum Angiospermae Chordata
Class
Dicotyledonae Reptilia
Sub-class
Polypetalae
Diapsida
Series
Thalamiflorae Order
Malvales
Squamata
Family
Malvaceae
Elapidae
Genus
Hibiscus
Naja
Species
Rosa-sinensis naja
Hierarchy of taxonomic categories :
Species : It is the basis unit in the system of
classification. Members of a species show all the
similar characters and are able to breed among
themselves to produce their own kind. For
Example, all the plants of potato (Solanum
tuberosum) are grouped under the species
tuberosum.
Genus : (Pl. genera) –
 It is a group of closely related species.
 E.g rosa- sinensis, esculentus, canabinus etc.
are different species under the genus
Hibiscus.
Family :
 A family represents a group of closely
related genera.
 The genera like Hibiscus, Malva, Sida,
Gossypium, Abutilon, etc. belong to the
family Malvaceae.
Order :
 It is a group of closely related families which
resemble in major characters.
 Families Malvaceae, Tiliaceae, Sterculiaceae
etc. belong to the order Malvales.
Sub-Class :

It is an assemblage of different orders
having some similarities.
The orders, Malvales, Ranales, Parietales
etc. have free petals and hence grouped
under the sub-class Polypetalae.
Class : It is a group of related sub-classes.
 The class Dicotyledonae includes subclasses as Polypetalae and Gamopetalae.
Division :
 The division is a category composed of
related classes.
 Division angiospermae includes two
classes-Dicotyledonae and Monocotyledonae.
Sub Kingdom :
 Different
divisions
having
similarities from sub-kingdom.

some
Division Angiospermae and Gymnospermae
will form the sub kingdom Phanerogams or
Spermatophyta.
Kingdom :
 It is the highest taxonomic category
composed of different sub Kingdoms.
 Sub-Kingdom
Phanerogams
and
Cryptogams, form the Plant kingdom.
Binomial Nomenclature :
A system of nomenclature of plants and animals
in which the scientific name consists of two
words or parts or epithets is called binomial
nomenclature.
 When a single species is described under
different names by different authors, then
these names are called synonyms. In such
cases the name under which the species is first
described is considered to be valid.
 These names are simple, meaningful, precise
and standard as they are accepted universally
 Due to this system confusion and uncertain
created by local or vernacular names is
avoided.
 The binomials are easy to understand and
remember.
 Indicate phylogeny (evolutionary history) of
organisms
and
help
to
understand
relationships between organisms, and groups
of organisms.
FIVE
KINGDOM
CLASSIFICATION :
The five kingdoms are :
1.
2.
3.
4.
5.
SYSTEM
OF
Kingdom Monera
Kingdom Protista
Kingdom Fungi
Kingdom Plantae
Kingdom Animalia
Kingdom : Monera
 The organisms included in this kingdom are
microscopic and prokaryotic, having a
primitive type of nucleus.
 The cells are without membrane bound cell
organelles
Rules of binomial nomenclature :
 The name of the organism is composed of
two Latin or Latinised or Greek words.
 The generic name is a simple noun should
come first and should begin with a small
letter.
 These scientific names must be underlined
separately if hand written and must be
printed in italics.
 The generic as well as specific name should
not have less than three letters and more than
thirteen letters.
 Usually the name of the author, who names a
plant or animal, is also written in full or in
abbreviated form after the scientific name.
 E.g. Mangifera indica L. where L. stands
for Linnaeus.
Composition :
The cell wall is rigid and composed of
peptidoglycan
Organisation :
These organisms are unicellular as in
eubacteria or filamentous as in cyanobacteria.
Locomotion :
These organisms are either motile (the
locomotion is due to gliding movement or
flagella. Cilia are absent or non-motile.
Nutrition :
The organisms exhibit different modes of
nutrition like autotrophic, heterotrophic,
parasitic or saprophytic. The autotrophs are
either photoautotrophs e.g. cyanobacteria or
chemoautotrophs e.g. Thiobacillus.
Reproduction :
 The mode of reproduction in Monera is
either asexual or with the help of fission or
budding. (Sexual reproduction, mitosis and
meiosis are absent)
Example :
- Archaebacteria e.g. – Methanobacillus,
Thiobacillus, etc.
- Eubacteria.
e.g – Rhizobium,
Clostridium
- Cyanobacteria e.g. – Nostoc,
Anabaena, etc.
- Actinomycetes e.g. – Streptomyces,
Mycobacterium, etc.
Kingdom – Protista ( Protoctista) :
Occurrence :
Fungi like protists :
They are saprophytic and lack cell wall e.g.
Smile moulds.
Kingdom - Fungi :
It is a unique kingdom of heterotrophic
organisms, showing extracelluar digestion.
Organisation :
The organisms are unicellular of multicellular
and filamentous.
Unicellular Organisms :

They have a protoplast with many nuclei.
e.g. Rhizopus.

Multicelluar organisms consist of a body
called mycelium in which a number of
thread-like structures called hyphae are
present. The hyphae may be with septa
(septate) or without septa (aseptate). They
may be uni or multi-nucleated. The nonseptate multinucleated hyphae are called
coenocytic hyphae.
 These organisms are unicellular, eukaryotic
and mostly aquatic. However, some are
terrestrial.
 They are either motile or non-motile. The
locomotory organs are cilia, flagella,
pseudopodia, etc.
Cell wall composition :
The protists are with or without cell wall. If
cell wall is present, it is composed of
cellulose.
Nutrition :
They show either photosynthetic, holozoic,
saprophytic or parasitic mode of nutrition.
The reserve food material is in the form of
glycogen or starch and fat.
Cell wall Composition :
The cell wall in fungi is composed of chitin
or fungal cellulose.
Nutrition :


Reproduction :
The reproduction is by asexual or sexual
method.
Reproduction :
Reproduction is vegetative, asexual of
sexual. (Example : Mucor, Rhizopus, Yeast,
Penicillum, Agaricus, ect.)
Asexual Reproduction :



Asexual reproduction occurs by mitotic or
amitotic cell division.
Sexual reproduction is by fusion of male
and female gametes forming zygote.
The zygote directly develops into young
individual without formation of embryo.
Plant like protists :
They are autotrophic (photosynthetic) have
cellulosic cell wall and store reserve food
as starch e.g. Dianoflagellates and Diatoms.
Animal like protists
:
These are heterotrophic, ingest food, lack cell
wall and store reserve food as glycogen.e.g
Amoeba, Paramoecium.
The fungi exhibit heterotrophic mode of
nutrition.
Most of the members are
saprophytes.
Some are parasites or predators and some are
symbiotic
Kingdom : Plantae
The Kingdom Plantae includes multicellular,
eukaryotic and autrophic organism
Cell wall Composition :

The cell wall of plant cells is composed of
true cellulose.

Photosynthetic pigments :- The members
possess photosynthetic pigments.

Reserve food material :- It is in the form of
starch.
Vascular tissues :

Vascular tissues are absent in the lower
plants (Algae and Bryophytes) but present
in
higher
plants
(Pteridophytes,
Gymnosperms and Angiosperms)
Reproduction :




The plants reproduce by vegetative, asexual
or sexual methods.
Vegetative reproduction : Vegetative
reproduction occurs with the help of
vegetative parts.
Asexual
reproduction
:
Asexual
reproduction with the help of spores.
Sexual reproduction: Sexual reproduction
takes place with the help of gametes.
Example :
- Algae
e.g. - Spirogyra, Chara, etc.
- Bryophytes
e.g. - Riccia, Funaria, etc.
- Pteridophytes e.g - Lycopodium, Nephrolepis,
etc.
- Gymnosperms e.g.- Cycas, Pinus, etc.
- Angiosperms e.g. – Sunflower, Jowar, etc.
Kingdom Animalia :




Occurance : The animals are multicellular
and eukaryotic and may be aquatic,
terrestrial, amphibious or aerial.
Locomotion : Majority of the animals are
motile. However a few like sponges are
sedentary.
Cell Wall Composition : The animals cells
do not possess cell wall, plastids and central
vacuole.
Nutrition : They are heterotrophic, mostly
holozoic and some are parasitic.
Advantages of S. Kingodom System :



The fungi are separated from Plantae on the
basis of their saprophytic mode of nutrition.
Organisms with doubtful placement like
Euglena get proper place in classification.
During redistribution of the organisms
among additional kingdom, the original subdivisions of old two-kingdom system are not
disturbed.
Drawbacks in five kingdom system. :


Viruses do not find any place in fivekingdom dystem of classification.
Kingdom Protista includes photosynthetic
and non-photosynthetic organisms, as well
as those with or without cell wall and it is
difficult to imagine them together.
LICHENS : The lichens are slow growing, long
living organisms, occurring in wide variety of
places.
Composition : Lichens are formed by close
association of two different partners (organisms)
one of which is an algal component and the other
is fungal component. The algal component is
called phycobiont or photobiont and it mostly
belongs to Chlorophyceae (green algae) or
cyanobacteria (blue green algae). The fungal
component is called mycobiont and it mostly
belongs
to
Ascomycetes
and
rarely
Basidiomycetes or Deuteromycetes.
Habitat :
 The Lichens are distributed in wide variety of
habitats. They grow on tree trunks, decaying
logs, and on soil too.
 They are sensitive to air pollution and
generally do not grow near the cities.
 They are thalloid, and the thallus is greenish or
bluish green in colour. Some lichens have
additional pigments such as yellow, orange,
brown and black.
Body structure :
On the basis of fungal components the lichens
are divided into three cagagories.
Type of lichens :
A) Ascolichens - In this category the fungal
partner belong to Ascomycetes.
B) Basidiolichens - Here the fungal partner
belongs to Basidiomycetes.
C) Deuterolichens – In this category the fungal
partner belongs to Deuteromycetes. These
are sterile lichens producing no spores.
On the basis of external form, (thallus
organization) the lichens are of three types
asA) Crustose Lichens - These are thin and flat
lichens occurring as crust on the bark or rock.
e.g. Graphis. Leanora, Haematomma etc.
B) Foliose Lichens - These are lobed and
dorsiventrally flattened, leafy lichens. They are
attached to substratum by hairy rhizoid like
structures called rhizines e.g. Parmelia, Collema,
Petligera.
C) Fruticose Lichens - These lichens are
commonly called shruby lichens. They have
cylindrical, branched and erect or pendulous
thallus which given them a shrub like
appearance.
They remain attached to the
substratum by basal mucilaginous disc. e.g.
Cladonia, Usnea, Alectoria.
The lichens generally reproduce by vegetative,
asexual and sexual methods.
Economic Importance of Lichens.
1) Lichens as Food :-- Several lichens are
used as food. The lichens contain as substance
lichenin which is similar to carbohydrate e.g.
Lecanora esculenta in Israel and Umbilicaria
esculenta in Japan. Parmelia is used in curry
powder as well as in making chocolates and
pestries.
Body Structure :
 Viruses show very simple structure i.e. a
nucleic acid core surrounded by a protein
coat (capsid) to form the nucleocapsid.
They posses their own genetic material in
the form of either DNA or RNA (but never
both).
 They can be crystallized.
 They can be stored for long period.
2) Lichens as Fodder :-- Lichens form a
favourite food for reindeers and cattles. Species
of Cladonia, Citraia, Evernia, Parmelia are
used as fodder.
Reproduction :
3) Medicinal Uses :-- Usnic Acid obtained
from the Usnea and Cladonia species is used as
an antibiotic against Gram positive bacteria,
Lobaria, Citraria species are, useful in
respiratory disease like T. B., Peltigera is useful
in hydrophobia, Parmelia is useful in epilepsy
and Usnea species in urinary disease. Some
lichens possess anticarcinogenic property.
Types of viruses : (Classification of viruses)
Viruses are classified into three groups on
the basis of their hosts.
1) Plant viruses :- The viruses which attack
and infect plants are called plant viruses.
These viruses consists of ss.-RNA or
ds-RNA. They show helical symmetry and
are mostly rod-shaped or cylindrical.
(e.g. : TMV)
2) Animal viruses :- The viruses which attack
and infect animals are called animal viruses.
The genetic material is either RNA or DNA.
They show radial symmetry. These are
mostly polyhedral in shape.
(e.g. : Herpes)
3) Bacterial viruses or Bacteriophages :(Greek phagin=eater). The viruses which
attack and infect the bacteria are called
bacteriophages or bacterial viruses. The
genetic matrial is DNA.
They were
discovered by Twort (1915). Felix d’ Herelle
named them as bacteriophages. They are
mostly tadpole shaped.
4) Industrial Uses of Lichens :-a) In Sweden na Russia, Lichens are used
for production of alcohol.
b) Lichens are used in the process of
tanning and dying.
c) In the litmus paper preparation which
used as acid-base indicator extract of
species of Rocella and Lasallia are used
d) Orcein a biological stain is obtained
from orchrolechia androgyna and O.
tortaria.
e) In Perfumery, species of Evernia and
Ramalina are the sources of essential
oils which are used in preparation of
soaps and other cosmetics.
Ecological Importance of Lichens :
The
lichens are the pioneers of vegetation on rocks.
Lichens are the first plants to settle on barren
rocks. Lichens bring about weathering of rocks
by releasing carbonic and oxalic acids.
Weathering of rocks leads to formation of soil
and is called pedogenesis.
VIRUSES AND VIROIDS :
Viruses :
Viruses are a cellular, highly
infectious microorganisms which are considered
to be on the threshold of life.
Size : Their size ranges from 10nm to 2000nm
Viruses do not grow, do not eat food or
respire.
They utilize the ribosomes and enzymes of
the host cell for synthesis of protein during
reproduction
Economic Importance of viruses :
The plant viruses and animal virues are of great
economic importance as they cause various
diseases in plants and animals.
Plant diseases caused by viruses are like –
1)
2)
3)
4)
5)
6)
7)
Little leaf of Brinjal
Yellow vein mosaic of lady’s finger.
Potato leaf roll
Leaf curl of papaya
Bunchy top of banana
Grassy shoot of sugarcane
Tabacco mosaic disease
Common symptoms due to viral infection
include –
Local lesions clearing of veins, mosaic
formation, chlorosis, necrosis, stunting and
premature defoliation, ring spotting, etc.
Animal diseases caused by viruses are like.
Disease
virus
1) Common cold - Rhino virus
2) Influenza
- Orthomyxo viruses
3) Small pox
- Variola virus
4) Mumps
- Myxovirus parotiditis
5) Mealses
- Morbilli virus
6) Poliomyelitis
- Polio viruses
7) Yellow fever
- Flavi virus
8) Swine flu
- H1N1 virus
9) AIDS
- Retro virus /HIV
Viroids :
These are very small, circular, single –
stranded RNAs which are not complexed with
any protein. (without protein coat) This RNA is
either covalently closed circular RNA or single
stranded linear RNA. These are mainly plant
pathogens.
The first viroid discovered was the potato
spindle tuber viroid (PSTV) which causes a
disease in potato. PSTV is composed of 359
nucleotides and thus has ten times less genetic
material than the smallest known virus. The
naked
RNA
molecule
can
replicate
autonomously in plant cells. It can also disperse
into the environment and produce disease.
*******************
Subject : Biology.
Topic : KINGDOM PLANTAE
INTRODUCTION : On the earth there is a
large number of living organisms, conmmonly
known as plants, animals and microorganisms.
All multicellular, eukaryotic organisms with
photosynthetic mode of nutrition are included
under kingdom Plantae. These are the main
producers on land and in water. With the help of
green pigments (chlorophylls) they synthesize
carbohydrates and release oxygen in air. Thus
they are the most essential biotic components of
the ecosystem.
Kingdom plantae is broadly classified into
two sub-kingdoms.
A) Cryptogamae B) Phanerogamae
Cryptogamae : Cryptogams are spore producing plants,
and do not produce seeds and flowers.
They reproduce sexually by gametes but
sex organs are concealed.
 Cryptogams include three major groups,
namely (a) Algae (b) Bryophytes (c)
Pteridophytes.
Habitate : Algae are mostly aquatic, some
being terrestrial also. A few alage grow on
other plants. Aquatic algae grow in marine
water or fresh water. Most of them are free
living while some are symbiotic.
Structure : The vegetative structure (thallus)
of algae display variety in organization and size.
Theymay be small, unicellular, microscopic like
chlorella (non-motile), chlamydomonas (motile)
or multicellular unbranched filamentous like
Spirogyra, or branched filamentous like Chara
or huge macroscopic such as sea weeds which
measure more than 60 meters in length e.g.
Sargassum.
Cell Composition :
 The algal cell wall consists of two layers i.e.
inner cellulosic and outer composed of
pectin.
 The algae consist of various type of
photosynthetic pigments.
Chlorophyll-a
(essential pigment) is present in all groups of
algae. The accessory pigments present are
chlorophyll-b, chlorophyll-c and chlorophylld, carotenes, xanthophylls and phycobilins.
Phycobilins are of two types i.e, phycocyanins
and phycoerythrins.
 The reserve food material is in the form of
starch,
laminarin-starch,
mannitol
or
floridean-starch, etc.
Reproduction :
 Algae reproduce by three different methods.
 Vegetative
reproduction
occurs
by
fragmentation (in filamentous forms) and cell
division (in inicellular forms.
 Asexual reproduction occurs by the formation
of various types of non- motile or motile
spores.
 Sexual reproduction takes place by formation
and fusion of gametes.
Occurrence :
 The bryophytes are mostly terrestrial plants
which depend of external water for
fertilization and completion of their life cycle.
Hence they are called amphibian plants.
Habitat :
The Bryophytes generally grow in shady and
moist places such as moist walls, damp rocks,
moist soil and on decaying logs.
Body Structure :
They show thalloid plant body which is not
differentiated into root, stem and leaves as in
liverworts. In mosses, thallus is foliose, i.e, it
bears leaf-like structures.
Rhizoids :
In Bryophytes true roots are absent but
rhizoids are present. Rhizoids are unicellular
in liverworts while multicelluar in mosses.
They absorb water and minerals and also help
in fixation of thallus to the substratum.
Vascular tissues :
The vascular tissue are absent. However, a
condicting strand of ew thick-walled cells is
present in mosses.
Leaves :
 Some bryophytes show leaf like structures
(e.g. moss) but they are not true leaves. They
do not produce flowers or seeds as well.
 Bryophytes show heteromorphic alternation
of generations. In which the gametophyte is
the dominant, green haploid and independent
phase while sporophyte is diploid recessive
and partially dependent on gametophyte.
Reproduction :
Bryophytes reproduce by vegetative means i.e,
by special structures like tubers and gemmae
while asexual reproduction takes place by spore
formation Sexual reproduction occurs by
formation of gametes.
Examples :
Liverworts e.g.
- Raccia ; Marchantia
Hornworts e.g.
- Anthoceros
Mosses
- Funaria.
e.g.
Division : Pteridophyta (pteron – feather :
phyton = plant) : The pterodophytes were the first vascular
plants on the land and are hence considered
as the first successful terrestrial plants.
 The Pteridohytes are also known s vascular
cryptogams.
Habitat : The Pteridophytes are terrestrial, small,
either annual or perennial, and grow
luxuriantly in moist and shady places. e.g.
ferns.
They may be aquatic (Azolla,
Marsilea), xerophytic (Equisetum) epiphytic
(Lycopodium) i.e. growing on large trunks
of trees.
Alo
 The pteridophytes show heteromorphic
alternation of generation in which the
sporophyte
is
diploid,
dominant,
autotrophic,
independent
and
is
differentiated into root, stem and leaves.
Root Structure :The primary root is short-lived and is soon
replaced by adventitious roots while the
Leaves :The leaves may be scaly (Equisetim), simple
and sessile (Lycopodium) or large and
pinnately compound (Ferns).
Vascular tissue. :In pteridophytes the xylem consists of only
tracheids and phloem consists of sieve cells
only. Secondary growth is not seen in
Pteridophytes due to absence of cambium.
Reproduction. :The sporophyte shows asexual reproduction
and produces spores by meiosis from which
the gametophyte develops. Gametophyte is
haploid recessive but independent, and
reproduces sexually. Product of sexual
reproduction, i.e. zygote produces diploid
sporophyte.
Apogamy - It is the development of the
sporophyte without the fusion of the male
and female gametes. It arises directly from
the gametophyte. Here the sporophyte is
haploid.
Apogamy It is the development of
thegametophyte from any cell of the
sporophyte other than the spores. Such a
gametophyte is diploid in nature.
Phanerogamae
The members of
Phanerogamae
i.e,
Phanerogams
are
commonly called seed plants. Which are
further divided into two divisions name
a) Gymnospermae b) Angiospermae.
Gymnospermae : Gymnosperms are the plants with naked
seeds.
 Most of the Gymnosperms are evergreen,
perennial woody trees or shrubs.
Vascular Tissue : They are vascular plants having xylem
with tracheids and phloem with sieve cells.
 The Gymnosperms show heteromorphic
alternation of generations. The sporophyte
is
diploid,
dominant,
autotrophic,
independent while the gametophyte is
haploid, recessive and dependent. (It is
much reduced and exists within
sporophyte.)
stem may be aerial or underground.
Vascular Tissue : They are vascular plants having xylem
with tracheids and phloem with sieve
cells.
 The Gymnosperms show heteromorphic
alternation of generations.
The
sporophyte is diploid, dominant,
autotrophic, independent while the
gametophyte is haploid, recessive and
dependent. (It is much reduced and
exists within sporophyte. )
Morphology : The plant body i.e. sporophyte is
differentiated into root, stem and leaves.
 The root system is well developed tap
root system. Coralloid roots of Cycas
show association with blue-green algae
roots of Pinus show association with
endophytic fungi called mycorrhizae.
Stem : The gymnospermic stem is mostly erect,
aerial, solid and cylindrical. In cycas it
is usually unbranched, while in conifers
it is branched.
 The leaves are dimorphic. The foliage
leaves are green, simple, needle like or
pinnately compound, where as scale
leaves are small, membranous and
brown.
Secondary
growth
is
seen
in
Gymnosperms due to presence of
cambiu.
Type of Spores :Gymnosperms are heterosporous. They
produce microspores (pollen grains) in
mocrosporangia and megaspores in
megasporangia (ovules). The sporangia
are borne on leafy structures called
sporophylls which are often aggregated
to form cones or strobili (sing-strobilus).
Reproduction : The pollination in Gymnosperm is
anemophilous (wind pollination) and direct
as the pollen grains are received directly in
the pollen chamber of the ovule.
Fertilization is achieved through a pollen
tube. This process is called siphonogamy.
 Vegetative reproduction takes place with the
help of bulbils.

Some Gymnosperms like Ginkgo biloba are
called living follils. It is because the plant is
found in living as well as follil form, and the
number of fossil forms is much more thena
the living forms.
ANGIOSPERMS :-


The Angiospermae is the most advanced
division of the flowering plants.
The
Angiosperms are flowering plants in which
seeds are enclosed within the fruit.
Habitat : The Angiosperms is a group of highly
evolved plants, primarily adapted to
terrestrial habitat.
They vary in size; e.g. Wolffia is the smallest
angiosperm, 1mm in size and Eucalyptus
grows to over 100 meters.
Marphology :


The plant body is differentiated into root,
stem and leaves. It has flowers, fruits and
seeds.
Vascular tissue are well developed. Xylem
shows vessels or tracheae while phloem has
sieve tubes and companion cells.
Angiosperms
show
heteromorphic
alternation of generation in which the
sporophyte is diploid, dominant, autotrophic
and independent while the gametophytes
(male or female) are recessive, haploid and
delepndent on the sporophyte. (exist within
sporophyte)
Reproduction Asexual reproduction :Angosperms are heterosporous. Microspores
(commonly called pollens) are formed in
microsporangia.
They develolop in highly
specialized microsporophylls or stamens while
megaspores are formed in megasporangia (or
ovules)
borne
on
highly
specialized
megasporophylls called carpels.
Pollination :- In Angiosperms the pollination is
indirect (pollen grains received on stigma) and
may be self or cross.
Sexual Reproduction :- These plants show
double fertilization. One male gamete fuses with
egg cell and another fuses with secondary
nucleus, to form embryo and endosperm
respectively. It occurs within the ovule, and
ovule changes to seed. The ovqer simultaneously
ripens into a fruit.
Class dictyledonae : These plants have two cotyledons in their
embryo.
 They have a tap root system and the stem is
generally profusely branched.
 The leaves show reticulate venation while
the flowers show tetra or pendamerous
symmetry.
 The vascular bundles are conjoint, collateral
and open. In dicots secondary growth is
commonly found.
Class Monocotyledonae : These plants have single cotyledon in their
embryo.
 They have adventitious root system and the
stem is rarely branched.
 The leaves generally have sheathing left
base and parallel venation while the flowers
are generally trimerous.
 The vascular bundles are conjoint, collateral
and closed. In monocots, secondary growth
is absent due to absence of cambium. (e.g.
Zea mays (Maize) Sorghum vulgare. Jowar)
Importance of Botanical Garderns :Botanical garders are important for

They records of local flora and as basis for
continued monographic work.

That provide vacilities for collection of
living plant material for studies.

Botanical gardens also supply seeds and
material for botanical investigations.

The botanical gardens in addition to
outdoor garden, may contain herbaria,
green houses, research laboratory and
library.
Botanical Gardens of India :
1) The Indian Botanical Gardern, Kolkata.
2) Lioyd Botanical Garden, Darheeling.
3) National botanical Garden, Lucknow.
4) Botanical Garden of the Forest Research
Institute, Dehradun.
5) Government
Botanical
Garden,
Ootacamund.
6) The State Botanical Garden, Lalbagh,
Mysore.
7) Botanical Garden, Saharanpur.
Herbaria : The collection or deposition of dried plant
material by using various techniques of
preservation and their arrangement in the
sequence of an accepted classification, forms
herbaria.
 A herbarium technique involves collection,
drying, poisoning, mounting, stitchning,
labeling and deposition.
 Herbaria are associated with research
institutes, scientific societies, botanic
gardens, universities and colleges.
 Herbaria can be classified into three main
categories such as –
a) Regional herbaria
b) Local herbaria and
c) Herbaria of educational institutions
including
schools,
colleges
and
universities.
Importance of herbaria :
The hyrbaria preserve national regional,
local plant wealth.

Help to carry out research programmes of
fundamental or of applied value.

It also facilitates exchange and loan of
preserved plant material for various
purpose like exhibitions, research etc.

It fulfils public demand by supplying plant
material and giving scientific information
regarding plants by arranging training
courses.
=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=
Metaphase :
 During metaphase, the condensation of chromosomes is completed and the thick
chromosomes get organized along equational plane of the cell.
 This phase is characterized by formation of kinetic spindle.
 In animal cells the spindle fibres radiate as an aster from centriole and called astral rays.
Hence it is called astral mitosis.
 In plant cells asters are absent and so it is called anastral mitosis.
Anaphase :
 Centromeres divide into two, resulting in the separation of chromatids. Each separated
chromatid is now called daughter chromosome
 The kinetic spindle now has four type of fibres made up of microtubules. They are
4) Telephase :
At the poles, daughter chromosomes uncoil and undergo hydration to from chromatin network.
The nuclear membrane begins to reappear around each group of aughter chromosomes and the
daughter nuclei are formed.
Cytokinesis :
The division of cytoplasm of the mother cell is called cytokinesis.
In animal cells it occurs by furrowing of plasma membrane that deepens and the daughter cells
ar formed. This process is called cleavage. In plant cells it takes place formation and extension
of cell plate, from centre to the periphery.
MEIOSIS :
Meiosis is a type of cell division, which involves halving of the chromosome number.
Therefore, it is termed as reduction division.
The meiotic division involves two successive divisions.
a) Meiosis-I or reduction division
b) Meiosis-II or equational division both of which have karyokinesis and cytokinesis
phase. Karyokinesis includes four phase like mitosis.
A) Meiosis – I or reduction division :
Interphase :
It is similar to that in mitosis.
Karyokinesis :
a) Prophase-I : It is furthet distinguished into five sub-stage viz, leptotene
i)
Leptotene or leptonema , ii) Zygotene or Zygonema, iii) Pachytene or
Pachynema, iv) Diplotene, v) Diakinesis,
i)
ii)
iii)
iv)
Leptotene or leptonema : During this phase the chromatin network condenses and
resolves into long and thin, thread like chromosomes.
Zygotene or Zygonema : It is a phase in which homologous chromosomes begin to pair
lengthwise . Such a pairing of chromosomes is called synapsis.
Pachytene or Pachynema :
 During this phase condensation of chrosomes progresses and they become short
and thick.
 During this process crossing over i.e, exchange of genetic material between nonsister chromatids of homolgous chromosomes takes place.
 It result in genetic recombination of parental characters.
 The points where crossing over takes place are called chiasmata.
Diplotene : The homologues now start repelling each other and begin to separate.
However, at the points of crossing over, they remain attached and thus chiasmata can be
seen. Nucleolus and nuclear membrane start disappearing.
v)
Diakinesis :
 During this phase chromosomes continue to condense and shorten.
 The chrasmata get shifted to the ends of chromatids called terminalisation.
 The nucleolus and nuclear membrane completely disappear and kinetic spindle
become apparent.
b) Metaphase – I
The spindle formation is complete and the bivalents move and arrange themselves at the
equatorial plane.
c) Anaphase –
The chromosomal fibres contract and pull the homologues and
inter-chromosomal fibres appear and extend so that homologous chromosomes start moving
towards opposite poles.
A) Telophase-I : The chromosomes uncoil to form chromatin. The spindle fibres
disappear. The nuclear membrane and nucleolus reappear forming two daughter nuclei.
Cytokinesis – I
Telophase-I is often followed by division of the cytoplasm.
B) Meiosis – II :
a) Prophase – II : During this phase the chromosomes with chromatids become
distinct. The nucleoius and nuclear membrane disappear.
b) Metaphase – II : During this phase spindle formation takes place and the
chromosomes move towards equatorial plane. The chromosomes get connected to the
respective poles by the chromosomal fibres.
c) Anaphase II : The centromere of each chromosome divides and chromatids are
separated. Each chromatid is now called daughter chromosome.
Telophase II : The daughter chromosomes which have gathered at each pole start
uncoiling . The nucleolus reappears and the nuclear membrane is formed around each
group of chromosomes forming two daughter nuclei.
Cytokinesis-II
Telephose-II is followed by division of cytoplasm of each cell forming two
daughter cells. At the end of meiosis-II four haploid daughter cells are thus formed.
Subject : Biology
Biochemistry of cell
Introduction :
Cell is a fundamental, structural and functional unit of an organism.
One of the major attributes of a living cell is its ability to carry of metabolic activities. To know how a tiny cell
can carry out the metabolic activities one has to understand the chemistry of various organic molecules, found
in cells. The collection of various types of molecules in a cell is known as cellular pool.
Metabolism, it indicates a variety of reactions carried out at cellular level. The metabolic reactions can be
divided into two main categories such as
i)
Anabolic reactions- The reactions in which biosynthesis of a new cellular material takes place.
ii)
Catabolic reactions- The reactions in which a complex storage product is hydrolyzed and or broken
down into smaller and simpler molecules.
Both, anabolic and catabolic reactions catalyzed by biological catalysts called enzymes.
BASIC CHEMICAL CONSTITUENTS OF CELL:
Carbohydrates:
Carbohydrates are the basic components food.
Carbohydrates are compounds of carbon, hydrogen and oxygen atoms.
The general formula is C H O for simple (C H O)n, for complex carbohydrates.
Rhamnose (C H O) and digitoxose (C H O) are carbohydrates, but do not follow general formula of
carbohydrates. Simple carbohydrates are commonly known as sugars.
Complex carbohydrates like starch, cellulose, etc.
Carbohydrate molecules are also characterized by the presence of either aldehyde (-CHO) or ketone (C=O)
group and two or more hydroxyl (-OH) groups.
Classification of carbohydrates
The three types are1) Monosaccharides
2) Disaccharides and
3) Polysaccharides
1) Monosaccharides:- Monosaccharides are compounds, which cannot be further hydrolyzed into still
smaller molecules.
Monosaccharides are further classified aldoses and ketoses
They consist of 3 to 6 carbon atoms. They are crystalline, soluble in water and sweet to taste.
On the basis of number of carbon atoms
the monosaccharides can be trioses, tetroses,pentoses, hexoses etc.
2) Desaccharides: Disaccharide is a carbohydrate made up of two monosaccharide units.
These are soluble in water, sweet to taste and crystalline. The covalent bond that joins monosaccharide
units is called glycosidic bond.
The most familiar disaccharides are sucrose, lactose, maltose.
3) Polysaccharides: These are complex carbohydrates formed by the condensation of large number of
monosaccharides. A single polysacchyaride may consist of thousands of units of monosaccharide may.
These are amorphous, tasteless and insoluble in water. A polysaccharide may contain one type of
monosaccharides (or homopolysaccharide) or different types of monosaccharides
(heteropolysaccharide).
The role of carbohydrates is (1) To provide energy for metabolism. (2) The monosaccharide like
glucose is main substrate for synthesis of ATP. (3) In mammals, disaccyharide lactose present in the
milk, provides energy to their babies. (4) The polysaccharedes serve as structural components of cell
membrane and cell wall and also serve as reserved food material (starch).
Proteins are long chain polymers of amino acids.
Serve as an important structural constituent of cells. Most of the proteins are host species and show
slight variations in each species. The differences among the species are due to differences in their
protein components.
All proteins consist of nitrogen in addition to the carbon, hydrogen and oxygen. Some protein
molecules contain sulphur and other elements in addition to C, H, O, and N.
In a long chain of amino acids forming a protein, the amino group (-NH) of one amino acid is linked to
the carboxyl (-COOH) group of the other amino acid. Two amino acids are condensed by removal of a
water molecule (OH from COOH and H from NH) to form a peptide linkage. The remainder of each
amino acid after removal of a water molecule (H+ and OH-) is called residue. A molecule of a protein
made up of two amino acid residues is called dipeptide, of three residues as residues as tripeptide and
of many residues as polypeptide.
Classification of proteins:
1) Simple proteins: These are composed of only amino acids or their derivatives. e.g. histones, zein
from maize.
2) Conjugated proteins: These are simple proteins (amino acids) with some non protein part called
prosthetic group.
Proteins play important role as –
Enzymes- Most of the enzymes are proteins ( all proteins are not enzymes) e.g. amylase.
Hormones- Hormones like insulin, growth hormones, etc. are proteins.
Structural Proteins- These proteins form parts of cells or tissues
Contractile proteins- These proteins occur in muscles. e.g.
Transport proteins- They are useful for transportation of certain materials e.g.
Defensive Proteins- They are useful for protection of the body against diseases. e.g.
Lipids:
Lipids are a group of organic components having oily or greasy consistency.
Lipids are a group of heterogenous compounds like fats, oils, steroids, waxes etc.
Lipids are insoluble in water but freely soluble in organic or non-polar solvents benzene, chloroform,
etc.
Similar to carbohydrates lipids are composed of C, H, O atoms
Compound lipids contain N, S and P in addition to C, H and O.
Classification of lipids:
Lipids are classified into 3 main types as1) Simple lipids
2) Compound lipids
3) Derived lipids
1) Simple lipids: These are esters of fatty acids with alcohol, Glycerol is a three-carbon alcohol with three
–OH groups. Fatty acid is a long straight chain of carbon atoms with a carboxyl (-COOH) group at one
end.
Saturated fatty acids - These fatty acids do not have double bond between carbon atoms of its chain
e.g. palmitic acid, stearic acid, etc.
Unsaturated fatty acids – These fatty acids contain one or more double bonds between carbon atoms of
its chain e.g. oleic acid, linoleic acid,
Fats containing unsaturated fatty acids liquid at room temperature and are called oils.
2) Compound lipids: These lipids contain some additional elements or groups in addition to fatty acids
and alcohol such as nitrogen, phosphorous, sulphur, protein, etc.
3) Derived lipids: These lipids are the hydrolytic products of lipids. They include – Steroids, waxes,
carotenoids, essential oils, etc.
a. Steroids: Steroids are structurally quite different from other lipids. Each molecule of steroid has
carbon atom arranged in four interlocking rings. Some of the biologically important steroids are
cholesterol, bile salts, male and female sex hormones
b. Waxes: Plant waxes are esters of saturated fatty acids with long chain alcohols and ketone. These
are secreted by epidermis and form a covering on stem, fruits and leaves. In animals, fur and feathers
are wax.
c. Carotenoids: Carotenoids are pigments composed of two, six-carbon rings with a highly
unsaturated strait chain of hydrocarbons.
For example, alpha and beta carotene, xanthophylls, etc.
Role of lipids :
1) Lipids act as high energy reserve food material e.g. oil seeds store oils.
2) They are important components of cell membrane of eukaryotes e.g.
3) Some of the lipids act as components of some enzyme systems.
4) Subcutaneous tissue contains fat which acts as insulator for heat.
5) Wax provides water proofing and checks the rate of transpiration in plants.
6) Steroids like cholic acid are constituents of bile.
7) Cholesterol takes part in the synthesis of vitamin D and is precursor molecule of many sex
hormones.
From the chemical analysis of nucleus it is clear that it consists of two types of nucleic acids i.e. DNA
(Deoxyribose nucleic acid) and RNA
Nucleic acids are macromolecules composed of many small units or monomers called nucleotides.
Each nucleotide is formed of three components i.e. a pentose (5c) sugar, a nitrogenous base and a phosphate
(phosphoric acid).
I)
Sugar - It is a pentose (5c) sugar. The sugars can be one of the two types i.e. ribose sugar or
deoxyribose sugar.
II)
Nitrogenous bases – Each nucleotide has one of the four types of nitrogenous bases out of which
two are purines and remaining two are pyrimidines. Purine bases are double ring compounds
III)
further distinguished into adenine and guanine while pyrimidine bases are single ring compounds
further distinguished into thymine, cytosine and uracil.
Phosphoric acid – Phosphate is present in nucleic acid (H PO)
DNA is double-stranded helix in which each strand is made up of thousands of deoxyribose
nucleotides.
The two strands of DNA molecule are antiparallel, complementary and are joined by weak Hbonds.
There are two –H bonds between adenine and thymine while three-H bonds between guanine and
cytosine. Total the number of purine bases is equal to that of purimidine bases. Thus purine:
pyrimidine ratio is 1:1.
In eukaryotic cell DNA is found mainly in mitochondria and chloroplasts. It is the genetic material
and contains all the information needed for development and existence of an organism.
Structure of Ribose Nucleic Acid (RNA)
RNA is single stranded and the strand may be straight or variously folded upon itself. The
nitrogenous -base thymine is replaced by uracil in RNA.
1) Genetic RNA : RNA is the genetic material in most of the plant viruses and some animal
viruses.
2) Non-genetic RNA: This type of RNA is present in organisms in which the genetic material is
DNA.
I) m-RNA (Messenger RNA):
(1) It is a linear moteaule. Its synthesis takes place on DNA by the process called
‘Transcription’.
(2) It carries genetic information from nucleus to the site of protein synthesis.
(3) It forms about 5% of the total cell RNA.
II) r-RNA (Ribosomal RNA):
(1) It is a linear molecule folded at certain regions due to complementation of nitrogenous bases.
(2) It is associated with ribosome.
(3) It forms about 80% of the total cell RNA.
III) t-RNA (Transfer RNA) :
(1) It is soluble RNA with hair pin or clover leaf like structure.
(2) This is the smallest among three types.
(3) It forms about 10-15% of the total cell RNA.
(4) It carries activated amino acids to ribosomes and helps in elongation of polypeptide chain
during the process of translation.
Enzymes:
In livings cells the reactions occur at normal body temperature and pressure due to the
presence of specialized macromolecular, proteinaceous substances called enzymes.
The enzymes that are produced within a cell for metabolic activities are known
endoenzymes those which act away from the site of synthesis are called exo-enzymes.
General properties of enzymes and factors affecting enzyme activity.
1) Enzymes accelerate the reaction but do not initiate it.
2) Enzymes themselves do not participate in the reaction and remain unchanged at the end
reaction.
3) The molecule of an enzyme is larger than that of substrate molecule and hence during
reaction a specific part of enzyme molecule comes in contact with the substrate molecule.
That part is called active site of enzyme.
4) Amphoteric nature: Chemically most of the enzymes are proteins and, therefore, show
amphoteric nature.
5) Specificity: Most of the enzymes are specific in their action.
6) Colloidal nature: All enzymes are colloidal in nature and thus provide large surface area
for reaction to take place.
7) Enzyme optima: Enzymes generally work best under certain narrowly defined conditions
referred to as optima.
8) Concentration of enzyme and substrate
The rate of reaction is proportionate to the concentration of the reacting molecules.
9) Enzyme inhibitors- Enzyme inhibitors are certain products which inhibit enzyme activity.
Some important Diagrams