DIVERSITY IN LIVINGDIVERSITY IN LIVING
ORGANISMSORGANISMS
SCIENCE

INTRODUCTION
Every organism whether plant or animal is
unique in itself. There is a wide diversity in the
flora (plants) and fauna (animals) in the world.
The diversity we see today is the result of 3.5
billion years of organic evolution. During the
course of this evolution several species
vanished from the surface of the Earth and
became extinct. It is estimated that more than
fifty times the existing species have become
extinct. With such a vast number of organisms
- both living and extinct, it becomes
impossible to study every one of them at
individual level. This task of studying the
diversity of living organisms can be made
easier and more effective if the various
organisms are arranged in an orderly manner.

PLANT KINGDOM
PLANT KINGDOM
CRYPTOGAMAE PHANEROGAMAE
THALOPHYTA BRYOPHYTA PTERIDOPHYTA
ALGAE
FUNGI
LICHENS
GYMNOSPERMAE ANGIOSPERMAE
MONOCOT
DICOT

• INTRODUCTION
• Eichler in 1883 suggested a system to classify
the plant kingdom which is well accepted. He
said that the plant kingdom is subdivided into
two subkingdoms: Cryptogamae and
Phanerogamae. sub kingdom cryptogamae are
lower plants that do not bear flowers or seeds.
They form three divisions.

THALLOPHYTATHALLOPHYTA
The plant body is not differentiated into stem, rootThe plant body is not differentiated into stem, root
and leaves but is in the form of an undividedand leaves but is in the form of an undivided
thallus.thallus.
Vascular tissues are absent.Vascular tissues are absent.
The reproductive organs are single-celled andThe reproductive organs are single-celled and
there is no embryo formation after fertilization.there is no embryo formation after fertilization.
This division includes three sub-divisions: algae,This division includes three sub-divisions: algae,
fungi and lichens.fungi and lichens.

BRIOPHYTA
• Moss and Liverwort belong to this variety of plants.
There are the simplest form of land plants. The plant
body is flat and lack true leaves and roots. The upper
surface of the plant body produces a stalk which bears
a capsule. The capsule contains spores.

PTERIDOPHYTAPTERIDOPHYTA
The plant body is differentiated intoThe plant body is differentiated into
stem, leaves and roots.stem, leaves and roots.
Vascular system is present.Vascular system is present.
Leaves usually have leaflets.Leaves usually have leaflets.
Spores are borne on theSpores are borne on the
undersurface of the leaf.undersurface of the leaf.
They grow in damp cool shadyThey grow in damp cool shady
places.places.

Example

ALGAEALGAE
► Occur in ponds, lakes and fresh waterOccur in ponds, lakes and fresh water
bodies. Sea weeds are found in marinebodies. Sea weeds are found in marine
waters.waters.
► May be single celled, colonial orMay be single celled, colonial or
filamentous.filamentous.
► Are autotropic i.e., they can prepare theirAre autotropic i.e., they can prepare their
own food with the help of the green pigmentown food with the help of the green pigment
i.e., chlorophyll present in the plant.i.e., chlorophyll present in the plant.
Sometimes red, blue, yellow and brownSometimes red, blue, yellow and brown
pigments are found.pigments are found.
► Blue-green bacteria (cyanobacteria) areBlue-green bacteria (cyanobacteria) are
included in this group of plants.included in this group of plants.

Examples

FUNGIFUNGI
 These do not contain chlorophyll and hence areThese do not contain chlorophyll and hence are
heterotropic and have diverse modes ofheterotropic and have diverse modes of
nutrition. They may be saprophytic i.e.,nutrition. They may be saprophytic i.e.,
depending on dead or decaying organic matterdepending on dead or decaying organic matter
for their food, or may be parasitic i.e.,for their food, or may be parasitic i.e.,
depending on living organisms for their fooddepending on living organisms for their food

ExampleExample

LICHENSLICHENS
1.1. This is a group which has twoThis is a group which has two
varieties of plants, an algae andvarieties of plants, an algae and
a fungus living in perfecta fungus living in perfect
harmony. They co-exist forharmony. They co-exist for
mutual benefit. This relationshipmutual benefit. This relationship
is known as symbiosis. Theis known as symbiosis. The
fungus absorbs water andfungus absorbs water and
mineral salts and supplies it tomineral salts and supplies it to
the alga. The alga prepares foodthe alga. The alga prepares food
and supplies it to the fungus.and supplies it to the fungus.

Examples

KINGDOM PHANEROGAMAEKINGDOM PHANEROGAMAE
This division is made up of plants that bear flowersThis division is made up of plants that bear flowers
and seeds and make up the majority of the largerand seeds and make up the majority of the larger
plants. The body is differentiated into true stem,plants. The body is differentiated into true stem,
leaves and roots. Propagation of the plant takes placeleaves and roots. Propagation of the plant takes place
with the help of seeds. Seeds are formed as a result ofwith the help of seeds. Seeds are formed as a result of
sexual reproduction. The male and female gametessexual reproduction. The male and female gametes
(sex cells) fuse together inside the ovary (female part(sex cells) fuse together inside the ovary (female part
of the flower) and develop into the seed. In someof the flower) and develop into the seed. In some
plants seed is not produced inside an ovary.plants seed is not produced inside an ovary.
Phanerogamae is made into two further divisions.Phanerogamae is made into two further divisions.
Gymnosperms (naked seeded plants)Gymnosperms (naked seeded plants)
Angiosperms (Seed borne within a fruit)Angiosperms (Seed borne within a fruit)

DIVISION GYMNOSPERMAE
• Gymnosperms are
intermediate between
cryptogams and
angiosperms. The male
flower is a cone which
produces pollen. The female
flower is much larger and
consists of a rosette of
carpels which bear ovules
along the two margins.

DIVISION ANGIOSPERME
• This group constitutes the largest group of plants.
Seeds are produced inside an ovary which later
becomes the fruit. These are highly evolved group of
plants. The plant body is distinctly differentiated into
roots, stem and leaves.
• Based on the number of cotyledons (seed-leaves)
that form the seed this group is divided into:
• Monocotyledons (One seed leaf)
Example: Rice, Wheat
Dicotyledons (two seed leaves)
Example: Beans, Mango

Animal Kingdom:- The following
classification “telescope” clearly indicates
the mechanism behind the classification of
the Animal Kingdom

The chart given below briefly outlines the classification of
the Animal Kingdom. ANIMALIA
PORIFERA
COELENTERATA
PLATYHELMINTHES
NEMATODA
ANNELIDA
ARTHROPODA
MOLLUSCA
PROTOCHORDATA
VERTEBRATA
PISCES AMPHIBIA REPTILA AVES MAMMALIA

PORIFERAPORIFERA
The simplest multicellularThe simplest multicellular
animals. The cells are looselyanimals. The cells are loosely
held together and do not formheld together and do not form
tissuestissues
Aquatic in habitat (mostlyAquatic in habitat (mostly
marine)marine)
Ostia (pores) are present allOstia (pores) are present all
over the body, with a singleover the body, with a single
large opening on top calledlarge opening on top called
osculumosculum
Food and oxygen enter theFood and oxygen enter the
organism along with water into aorganism along with water into a
canal systemcanal system
Support system made up of tinySupport system made up of tiny
needle-like formations. Theyneedle-like formations. They
may be made of silica, calciummay be made of silica, calcium
or spongin fibresor spongin fibres
Reproduction may be sexual,Reproduction may be sexual,
asexual or buddingasexual or budding
Example: Sycon, Spongilla,Example: Sycon, Spongilla,
EuptectellaEuptectella

COLLENTERATACOLLENTERATA Two layered body which is radiallyTwo layered body which is radially
symmetricalsymmetrical
Aquatic in habitat which includes both freshAquatic in habitat which includes both fresh
water and marinewater and marine
The outer layer has tentacles armed withThe outer layer has tentacles armed with
stinging cells cnidoblasts which can releasestinging cells cnidoblasts which can release
venom into the victim. The inner layervenom into the victim. The inner layer
encloses a body cavity called gastroencloses a body cavity called gastro
vascular cavityvascular cavity
Animals in this group exist in two types ofAnimals in this group exist in two types of
individuals called zooids - polyps andindividuals called zooids - polyps and
medusae. Polyps are fixed and lead solitarymedusae. Polyps are fixed and lead solitary
or colonial life, while medusae are freeor colonial life, while medusae are free
swimmingswimming
Alternation of generation takes place inAlternation of generation takes place in
colonial forms. Polyps and medusaecolonial forms. Polyps and medusae
alternate with each other during the life cyclealternate with each other during the life cycle
Reproduction is usually asexual i.e., byReproduction is usually asexual i.e., by
budding in the polyp form and sexual inbudding in the polyp form and sexual in
medusa formmedusa form
Exoskeleton made of lime is found in coralsExoskeleton made of lime is found in corals
Example: Hydra, Obelia, Aurelia, MetridiumExample: Hydra, Obelia, Aurelia, Metridium

PLATYHELMINTHESPLATYHELMINTHES
Simplest triploblasticSimplest triploblastic
organisms showing bilateralorganisms showing bilateral
symmetrysymmetry
Mostly parasites in otherMostly parasites in other
animalsanimals
Body in dorsoventrally flatBody in dorsoventrally flat
and leaf-like or ribbon-likeand leaf-like or ribbon-like
with bilateral symmetrywith bilateral symmetry
The body cavity has only oneThe body cavity has only one
opening which serves asopening which serves as
both the mouth and the anusboth the mouth and the anus
Hermaphrodites i.e, maleHermaphrodites i.e, male
and female sex organsand female sex organs
present in one individualpresent in one individual
Example: Planaria, LiverExample: Planaria, Liver
Fluke, Tape WormFluke, Tape Worm

ANNELIDAANNELIDA
Occur in moist soil, fresh waterOccur in moist soil, fresh water
and seaand sea
Body is soft and segmented,Body is soft and segmented,
triploblastic with bilateraltriploblastic with bilateral
symmetrysymmetry
First animal with the coelomFirst animal with the coelom
(body cavity)(body cavity)
Body is covered by a non-Body is covered by a non-
chintinous cuticle which maychintinous cuticle which may
have chitinous setae, orhave chitinous setae, or
parapodiaparapodia
Reproduction is generallyReproduction is generally
sexual, but some may reproducesexual, but some may reproduce
asexually by rejuvination i.e, byasexually by rejuvination i.e, by
regrowing broken segmentsregrowing broken segments
Example: Nereis (sand worm),Example: Nereis (sand worm),
Aphrodite (sea mouse),Aphrodite (sea mouse),
Pheretima (earthworm),Pheretima (earthworm),
Hirudinaria (leech)Hirudinaria (leech)

ARTHROPODAARTHROPODA ► This is the largest phylum withThis is the largest phylum with
almost 80% of the animalalmost 80% of the animal
kingdom kingdom
► Body is bilaterally symmetricalBody is bilaterally symmetrical
and segmented. It is dividedand segmented. It is divided
into head, thorax andinto head, thorax and
abdomen abdomen
► Possess jointed legs whichPossess jointed legs which
may be modified for walking,may be modified for walking,
swimming feeding and feeling swimming feeding and feeling
► Exoskeleton is chitinous whichExoskeleton is chitinous which
is shed periodically by moultingis shed periodically by moulting
► Body cavity is reduced andBody cavity is reduced and
filled with blood (haemocoel) filled with blood (haemocoel)
► Respiration is by lungs, bookRespiration is by lungs, book
lung and trachealung and trachea
► Example: Apis (honey bee),Example: Apis (honey bee),
Araneae (Spider), PalaemonAraneae (Spider), Palaemon
(prawn), Scolopendra(prawn), Scolopendra
(Centipede) (Centipede)

MOLLUSCA
 Aquatic in habitat but
some land forms are
also seen
 Body is soft and divided
into three regions
(head, dorsal visceral
mass and ventral foot)
 Body enclosed in a hard
calcareous she
 Breathe through gills,
land molluscs have
lungs
 Sexes are separate
 Example: Chiton, Pila
(snail), unio (fresh water
mussel), octopus

ECHINODERMATAECHINODERMATA Marine in habitatMarine in habitat
Body is radiallyBody is radially
symmetrical, starsymmetrical, star
shaped, spherical orshaped, spherical or
elongate, Exoskeleton iselongate, Exoskeleton is
spinyspiny
Head is absent and fiveHead is absent and five
radially arranged armsradially arranged arms
presentpresent
Locomotion is with theLocomotion is with the
help of tube feethelp of tube feet
Sexes are separateSexes are separate
Example: Asterias (starExample: Asterias (star
fish), Echinus (seafish), Echinus (sea
urchin), Holothuria (seaurchin), Holothuria (sea
cucumber), Antedoncucumber), Antedon

REPTILEREPTILE Mostly terrestrialMostly terrestrial
Heart is 3 chambered,Heart is 3 chambered,
is cold bloodedis cold blooded
Breathe through lungsBreathe through lungs
Body covered withBody covered with
scalesscales
Have two pairs ofHave two pairs of
pentadactyl (five digit)pentadactyl (five digit)
limbs which are absent inlimbs which are absent in
snakessnakes
Example:Example: HemidactylusHemidactylus
(wall lizard), chameleon,(wall lizard), chameleon,
Draco (flying lizard)Draco (flying lizard)
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AMPHIBIAAMPHIBIA
Live in both water and onLive in both water and on
landland
Respiration is by gills,Respiration is by gills,
lungs or skinlungs or skin
3 chambered heart3 chambered heart
Is cold bloodedIs cold blooded
Have two pairs ofHave two pairs of
pentadactyl (5 digit) limbspentadactyl (5 digit) limbs
which may be absent inwhich may be absent in
some casessome cases

AVESAVES
Arboreal in habitat i.e, theArboreal in habitat i.e, they
live on treeslive on trees
Warm blooded. 4Warm blooded. 4
chambered heartchambered heart
Body covered withBody covered with
feathersfeathers
Lungs have membranousLungs have membranous
extensions called air sacsextensions called air sacs
to make the body lightto make the body light
Mouth is surrounded by aMouth is surrounded by a
beak. Teeth are absentbeak. Teeth are absent
Fore-limbs are modifiedFore-limbs are modified
into wingsinto wings

MAMMALIAMAMMALIA Most intelligent of allMost intelligent of all
organismsorganisms
Warm blooded with 4Warm blooded with 4
chambered heartchambered heart
Give birth to young onesGive birth to young ones
The mother suckles herThe mother suckles her
young ones on milkyoung ones on milk
secreted by specialsecreted by special
glands called mammaryglands called mammary
glandsglands
Body covered with hairBody covered with hair
Have two pairs ofHave two pairs of
pentadactyl limbspentadactyl limbs
Breathe through lungsBreathe through lungs
I AM I A
MAMMAL?