DIVERSITY IN LIVING DIVERSITY IN LIVING ORGANISMSORGANISMS

SCIENCE

INTRODUCTIONEvery 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 KINGDOMPLANT 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, root The plant body is not differentiated into stem, root and leaves but is in the form of an undivided and 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 and The 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 into The 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 the Spores are borne on the undersurface of the leaf. undersurface of the leaf.

They grow in damp cool shady They grow in damp cool shady places. places.

Example

ALGAEALGAE► Occur in ponds, lakes and fresh water Occur in ponds, lakes and fresh water

bodies. Sea weeds are found in marine bodies. Sea weeds are found in marine waters. waters.

► May be single celled, colonial or May be single celled, colonial or filamentous. filamentous.

► Are autotropic i.e., they can prepare Are autotropic i.e., they can prepare their own food with the help of the their own food with the help of the green pigment i.e., chlorophyll present green pigment i.e., chlorophyll present in the plant. Sometimes red, blue, in the plant. Sometimes red, blue, yellow and brown pigments are found. yellow and brown pigments are found.

► Blue-green bacteria (cyanobacteria) Blue-green bacteria (cyanobacteria) are included in this group of plants. are included in this group of plants.

Examples

FUNGIFUNGI These do not contain chlorophyll and These do not contain chlorophyll and

hence are heterotropic and have diverse hence are heterotropic and have diverse modes of nutrition. They may be modes of nutrition. They may be saprophytic i.e., depending on dead or saprophytic i.e., depending on dead or decaying organic matter for their food, or decaying organic matter for their food, or may be parasitic i.e., depending on living may be parasitic i.e., depending on living organisms for their food organisms for their food

ExampleExample

LICHENSLICHENS1.1. This is a group which has two varieties This is a group which has two varieties

of plants, an algae and a fungus living of plants, an algae and a fungus living in perfect harmony. They co-exist for in perfect harmony. They co-exist for mutual benefit. This relationship is mutual benefit. This relationship is known as symbiosis. The fungus known as symbiosis. The fungus absorbs water and mineral salts and absorbs water and mineral salts and supplies it to the alga. The alga supplies it to the alga. The alga prepares food and supplies it to the prepares food and supplies it to the fungus. fungus.

Examples

KINGDOM PHANEROGAMAEKINGDOM PHANEROGAMAE

This division is made up of plants that bear flowers This division is made up of plants that bear flowers and seeds and make up the majority of the larger and 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 place leaves and roots. Propagation of the plant takes place with the help of seeds. Seeds are formed as a result of with the help of seeds. Seeds are formed as a result of sexual reproduction. The male and female gametes sexual 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 some of 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 multicellular The simplest multicellular animals. The cells are loosely animals. The cells are loosely held together and do not form held together and do not form tissues tissues Aquatic in habitat (mostly Aquatic in habitat (mostly marine) marine) Ostia (pores) are present all Ostia (pores) are present all over the body, with a single over the body, with a single large opening on top called large opening on top called osculum osculum Food and oxygen enter the Food and oxygen enter the organism along with water into a organism along with water into a canal system canal system Support system made up of tiny Support system made up of tiny needle-like formations. They needle-like formations. They may be made of silica, calcium may be made of silica, calcium or spongin fibres or spongin fibres Reproduction may be sexual, Reproduction may be sexual, asexual or budding asexual or budding Example: Sycon, Spongilla, Example: Sycon, Spongilla, Euptectella Euptectella 

COLLENTERATACOLLENTERATA Two layered body which is radially Two layered body which is radially symmetrical symmetrical Aquatic in habitat which includes both fresh Aquatic in habitat which includes both fresh water and marine water and marine The outer layer has tentacles armed with The outer layer has tentacles armed with stinging cells cnidoblasts which can release stinging cells cnidoblasts which can release venom into the victim. The inner layer venom into the victim. The inner layer encloses a body cavity called gastro encloses a body cavity called gastro vascular cavity vascular cavity Animals in this group exist in two types of Animals in this group exist in two types of individuals called zooids - polyps and individuals called zooids - polyps and medusae. Polyps are fixed and lead solitary medusae. Polyps are fixed and lead solitary or colonial life, while medusae are free or colonial life, while medusae are free swimming swimming Alternation of generation takes place in Alternation of generation takes place in colonial forms. Polyps and medusae colonial forms. Polyps and medusae alternate with each other during the life cycle alternate with each other during the life cycle Reproduction is usually asexual i.e., by Reproduction is usually asexual i.e., by budding in the polyp form and sexual in budding in the polyp form and sexual in medusa form medusa form Exoskeleton made of lime is found in corals Exoskeleton made of lime is found in corals Example: Hydra, Obelia, Aurelia, Metridium Example: Hydra, Obelia, Aurelia, Metridium 

PLATYHELMINTHESPLATYHELMINTHESSimplest triploblastic Simplest triploblastic organisms showing bilateral organisms showing bilateral symmetry symmetry Mostly parasites in other Mostly parasites in other animals animals Body in dorsoventrally flat Body in dorsoventrally flat and leaf-like or ribbon-like and leaf-like or ribbon-like with bilateral symmetry with bilateral symmetry The body cavity has only one The body cavity has only one opening which serves as opening which serves as both the mouth and the anus both the mouth and the anus Hermaphrodites i.e, male Hermaphrodites i.e, male and female sex organs and female sex organs present in one individual present in one individual Example: Planaria, Liver Example: Planaria, Liver Fluke, Tape Worm Fluke, Tape Worm

ANNELIDAANNELIDAOccur in moist soil, fresh water Occur in moist soil, fresh water and sea and sea Body is soft and segmented, Body is soft and segmented, triploblastic with bilateral triploblastic with bilateral symmetry symmetry First animal with the coelom First animal with the coelom (body cavity) (body cavity) Body is covered by a non-Body is covered by a non-chintinous cuticle which may chintinous cuticle which may have chitinous setae, or have chitinous setae, or parapodia parapodia Reproduction is generally Reproduction is generally sexual, but some may reproduce sexual, but some may reproduce asexually by rejuvination i.e, by asexually by rejuvination i.e, by regrowing broken segments regrowing 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 This is the largest phylum with almost 80% of the with almost 80% of the animal kingdom animal kingdom 

► Body is bilaterally Body is bilaterally symmetrical and symmetrical and segmented. It is divided into segmented. It is divided into head, thorax and abdomen head, thorax and abdomen 

► Possess jointed legs which Possess jointed legs which may be modified for may be modified for walking, swimming feeding walking, swimming feeding and feeling and feeling 

► Exoskeleton is chitinous Exoskeleton is chitinous which is shed periodically by which is shed periodically by moulting moulting

► Body cavity is reduced and Body cavity is reduced and filled with blood filled with blood (haemocoel) (haemocoel) 

► Respiration is by lungs, book Respiration is by lungs, book lung and trachea lung and trachea

► Example: Apis (honey bee), Example: Apis (honey bee), Araneae (Spider), Palaemon Araneae (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 habitat Marine in habitat Body is radially Body is radially symmetrical, star symmetrical, star shaped, spherical or shaped, spherical or elongate, Exoskeleton is elongate, Exoskeleton is spiny spiny Head is absent and five Head is absent and five radially arranged arms radially arranged arms present present Locomotion is with the Locomotion is with the help of tube feet help of tube feet Sexes are separate Sexes are separate Example: Asterias (star Example: Asterias (star fish), Echinus (sea fish), Echinus (sea urchin), Holothuria (sea urchin), Holothuria (sea cucumber), Antedon cucumber), Antedon (feather star) (feather star)

REPTILEREPTILE Mostly terrestrial Mostly terrestrial

Heart is 3 chambered, Heart is 3 chambered, is cold blooded is cold blooded

Breathe through lungs Breathe through lungs

Body covered with Body covered with scales scales Have two pairs of Have two pairs of pentadactyl (five digit) pentadactyl (five digit) limbs which are absent in limbs which are absent in snakes snakes 

Example:Example:  Hemidactylus  Hemidactylus (wall lizard), chameleon, (wall lizard), chameleon, Draco (flying lizard)Draco (flying lizard)

BBooddyy ccoovveerreedd wwiitthh ssccaalleess

  

AMPHIBIAAMPHIBIALive in both water and on Live in both water and on land land

Respiration is by gills, Respiration is by gills, lungs or skin lungs or skin 

3 chambered heart 3 chambered heart

Is cold blooded Is cold blooded 

Have two pairs of Have two pairs of pentadactyl (5 digit) limbs pentadactyl (5 digit) limbs which may be absent in which may be absent in some cases some cases

AVESAVESArboreal in habitat i.e, they Arboreal in habitat i.e, they live on trees live on trees

Warm blooded. 4 Warm blooded. 4 chambered heart chambered heart

Body covered with Body covered with feathers feathers 

Lungs have membranous Lungs have membranous extensions called air sacs extensions called air sacs to make the body light to make the body light

Mouth is surrounded by a Mouth is surrounded by a beak. Teeth are absent beak. Teeth are absent 

Fore-limbs are modified Fore-limbs are modified into wings into wings

MAMMALIAMAMMALIA Most intelligent of all Most intelligent of all organisms organisms 

Warm blooded with 4 Warm blooded with 4 chambered heart chambered heart 

Give birth to young ones Give birth to young ones

The mother suckles her The mother suckles her young ones on milk young ones on milk secreted by special secreted by special glands called mammary glands called mammary glands glands 

Body covered with hair Body covered with hair

Have two pairs of Have two pairs of pentadactyl limbs pentadactyl limbs 

Breathe through lungs Breathe through lungs 

I AM I A MAMMAL?