1

ADARSH TUITION CENTRE

CH-7

DIVERSITY IN LIVING ORGANISMS

CLASSIFICATION AND EVOLUTIONP CLASSIFICATION REFERS TO THE IDENTIFICATION, NAMING, AND GROUPING OF ORGANISMS INTO A

FORMAL SYSTEM BASED ON SIMILARITIES IN THEIR INTERNAL AND EXTERNAL STRUCTURE OR

EVOLUTIONARY HISTORY. IT DETERMINES THE METHODS OF ORGANIZING DIVERSITY OF LIFE ON EARTH.

THEREFORE, CLASSIFICATION HELPS IN UNDERSTANDING MILLIONS OF LIFE FORMS IN DETAIL. WHO STARTED THE CLASSIFICATION OF ORGANISMS? LET US EXPLORE THE HISTORY OF CLASSIFICATION. HISTORY OF CLASSIFICATION ONE OF THE EARLIEST SCHEMES OF CLASSIFICATION WAS GIVEN BY THE GREEK THINKER, ARISTOTLE, AROUND 300 BC. HE CLASSIFIED ANIMALS ACCORDING TO THEIR HABITAT – LAND, AIR, OR WATER. HOWEVER, THIS CLASSIFICATION OF ARISTOTLE WAS MISLEADING BECAUSE ANIMALS THAT LIVE ON LAND

INCLUDE EARTHWORMS, MOSQUITOES, BUTTERFLIES, RATS, ELEPHANTS, TIGERS ETC. THESE ANIMALS DO

NOT RESEMBLE EACH OTHER EXCEPT THAT THEY SHARE A COMMON HABITAT. SIMILARLY, ALL AQUATIC ANIMALS DO NOT RESEMBLE EACH OTHER. THEREFORE, A NEW SYSTEM OF CLASSIFICATION WAS DEVELOPED TO CLASSIFY THE VAST DIVERSITY OF

ORGANISMS PRESENT ON EARTH. PRINCIPLES OF CLASSIFICATION FOLLOWED TODAY INCLUDE: NATURE OF CELL: NATURE OF THE CELL IS CONSIDERED TO BE THE FUNDAMENTAL FEATURE, AS IT GIVES

RISE TO ANOTHER FEATURE CALLED CELLULARITY. IT INCLUDES THE PRESENCE OR ABSENCE OF MEMBRANE-BOUND ORGANELLES. THEREFORE, ON THE BASIS OF THIS FUNDAMENTAL CHARACTERISTIC, WE CAN

CLASSIFY LIVING ORGANISMS INTO TWO BROAD CATEGORIES OF EUKARYOTES ANDPROKARYOTES. CELLULARITY: UNICELLULAR ORGANISMS ARE THOSE ORGANISMS WHOSE BODY IS MADE UP OF A SINGLE

CELL, WHEREAS MULTICELLULAR ORGANISMS ARE THOSE ORGANISMS WHOSE BODY IS MADE UP OF MANY

CELLS. MULTICELLULAR ORGANISMS USE THE PRINCIPLE OF DIVISION OF LABOUR TO PERFORM SPECIALIZED

FUNCTIONS. THIS RESULTS IN A SPECIFIC BODY DESIGN THAT DISTINGUISHES MULTICELLULAR ORGANISMS

FROM UNICELLULAR ORGANISMS. MODE OF NUTRITION: THE MODE OF NUTRITION ALSO DISTINGUISHES DIFFERENT ORGANISMS. THE

ABILITY TO MANUFACTURE THEIR OWN FOOD MAKES THE BODY DESIGN OF PLANTS DIFFERENT FROM THAT

OF ANIMALS. THIS FURTHER EXTENDS OUR CLASSIFICATION AS SHOWN BELOW:

2

CLASSIFY ANIMALS LOOK AT THE PICTURES GIVEN BELOW

DIFFERENT LIFE FORMS CAN YOU DIVIDE THESE ANIMALS INTO FOUR GR

THESE ANIMALS CAN BE GROUPED AS FOLLOWS

(I) SEAHORSE, FISH: THESE ARE EXCLUSIVELY

GILLS. (II) LIZARD, SNAKE: THESE ARE COLD

BODY. THEY BREATHE THROUGH

GIVEN BELOW.

ANIMALS INTO FOUR GROUPS AND CAN YOU GIVE REASONS FOR EACH D

GROUPED AS FOLLOWS: HESE ARE EXCLUSIVELY WATER-INHABITING ANIMALS. THEY BREATHE THROUGH

HESE ARE COLD-BLOODED ANIMALS. THEY LAY EGGS AND HAVE SCALES ON THEIR

HEY BREATHE THROUGH LUNGS.

E REASONS FOR EACH DIVISION?

HEY BREATHE THROUGH

E SCALES ON THEIR

3

(III) PIGEON, SPARROW: THESE ARE WARM

THEIR BODY. (IV) CHIMPANZEE, MONKEY: TCONCLUSION: CHARACTERISTICS CAN B

ORGANISMS, AND THEN THESE ORGAN

HIERARCHY OF CLASSIFICATION

HIERARCHY REFERS TO THE ORGANI

IMPORTANCE. WHO DEVELOPED THE HIERARCHY OF CLASSIFICA

CAROLUS LINNAEUS DEVELOPED TH

POSSESSED BY AN ORGANISM.

FOR CLASSIFYING ORGANISMS.ACCORDING TO THIS SYSTEM, INTO CLASSES; LATER IT WAS GROUPED

FURTHER SUB-DIVIDED INTO SMALLER GR

GENUS IS DIVIDED INTO SPECIES

HIERARCHY OF CLASSIFICATION

WHAT IS SPECIES? A SPECIES CAN BE DEFINED AS A

PRODUCING A FERTILE OFFSPRING

BUT HOW DOES CLASSIFICATION HELP IN DETER

DO YOU KNOW WHAT EVOLUTION IS

EVOLUTION MOST OF THE LIFE FORMS THAT WE SEE TODAY

THE BODY DESIGN OF ANCIENT ORGANISMS

OVER A LONG PERIOD OF TIME IS TERMED AS

SURROUNDINGS. CLASSIFICATION ALLOWS THINGS TO BE

FUNCTION OF AN ORGANISM, AND ACCORDINGLY

ORGANISMS. THIS HELPS IN PREDICT

HESE ARE WARM-BLOODED ANIMALS. THEY LAY EGGS AND HAV

THEY HAVE MAMMARY GLANDS AND PRODUCE YOUNG ONES

HARACTERISTICS CAN BE COMPARED TO FIND OUT SIMILARITIES BETWEEN VARIOUS

AND THEN THESE ORGANISMS CAN BE CLASSIFIED INTO GROUPS. LASSIFICATION

REFERS TO THE ORGANIZATION OR CLASSIFICATION OF THINGS IN ORDER OF R

RARCHY OF CLASSIFICATION? INNAEUS DEVELOPED THE HIERARCHY OF CLASSIFICATION ON THE BASIS OF CHARACTERISTIC

THE LINNAEUS SYSTEM OF CLASSIFICATION IS STILL THE BASIC FRAMEWORK

. KINGDOM IS THE HIGHEST RANK. LINNAEUS DIVIDED EACH

LATER IT WAS GROUPED INTO PHYLA FOR ANIMALS AND DIVISIONS FOR PLANTS

IDED INTO SMALLER GROUPS – ORDER AND FAMILY, THEN GENUS, AND FINALLY

PECIES. THUS, SPECIES IS THE BASIC UNIT OF CLASSIFICATION.

CATION

CAN BE DEFINED AS A GROUP OF INTERBREEDING ORGANISMS THAT ARE CAPABLE OF

OFFSPRING. CATION HELP IN DETERMINING THE EVOLUTIONARY HISTORY OF ORGAN

UTION IS?

S THAT WE SEE TODAY HAVE ARISEN FROM THE ACCUMULATION OF CHANGES

NCIENT ORGANISMS. THIS SLOW CHANGE IN THE BODY DESIGN OF AN

F TIME IS TERMED AS EVOLUTION. IT HELPS AN ORGANISM TO SURVIVE IN ITS

ALLOWS THINGS TO BE IDENTIFIED AND CATEGORIZED ON THE BASIS OF S

AND ACCORDINGLY, WE CAN REFER TO THEM AS PRIMITIVE OR ADVA

HIS HELPS IN PREDICTING THE LINE OF EVOLUTION.

HEY LAY EGGS AND HAVE FEATHERS ON

RODUCE YOUNG ONES. EEN VARIOUS

THINGS IN ORDER OF RANK OR

IS OF CHARACTERISTICS

BASIC FRAMEWORK

INNAEUS DIVIDED EACH KINGDOM

FOR PLANTS. CLASS IS

AND FINALLY, EACH

.

APABLE OF

ARY HISTORY OF ORGANISMS?

UMULATION OF CHANGES IN

HE BODY DESIGN OF AN ORGANISM

TO SURVIVE IN ITS

ED ON THE BASIS OF STRUCTURE AND

AS PRIMITIVE OR ADVANCED

4

WHICH CHARACTERISTIC DO YOU CONSIDER BASI

LATER? THE CHARACTERISTIC THAT CAME INTO EXISTEN

OTHER CHARACTERISTICS, IN TERMS OF THEIR EF

ORGANISM. FOR EXAMPLE, CELL STRUCTURE

ORGANISM THAT IS TO BE CLASSIFIED

PRIMITIVE AND ADVANCED ORGANISMS

A PRIMITIVE OR A LOWER ORGANISM HAS A SIMPL

FEATURES, WHICH HAVE NOT CHANG

AN ADVANCED ORGANISM OR A HIGHER ORGANISM

ORGANIZATION. THUS, WE CAN CONCLUDE THAT

COMPLEX ORGANISMS.

IT MEANS THAT THE EXISTING ANIMALS AND PL

CONTINUOUS CHANGE IN PRIMITIVE OR SIMPLE

WHICH OF THE FOLLOWING TWO ORGANISMS DO Y

AMOEBA AND STARFISH

A PRIMITIVE ORGANISM HAS A SIMPLE BODY

HAVE NOT CHANGED MUCH OVER TIME.

STARFISH, WHICH IS MORE ADVANCED.

FIVE KINGDOMS OF CLASSIFICATION

ALL ORGANISMS PRESENT ON EARTH ARE CLASSIF

THE FIVE-KINGDOM CLASSIFICATI

KINGDOMS? KINGDOM IS THE HIGHES

LINNAEUS’ SYSTEM OF CLASSIFICA

KINGDOM CLASSIFICATION OF LIVING ORGANIS

THE FIVE KINGDOMS PROPOSED BY

PLANTAE, AND ANIMALIA. CARL WOESE FURTHER DIVIDED

ENVIRONMENT THEY ARE ABLE TO INHABIT

DO YOU CONSIDER BASIC – THE ONE THAT CAME INTO EXISTENC

AT CAME INTO EXISTENCE EARLIER IS BASIC BECAUSE THEY ARE IND

IN TERMS OF THEIR EFFECTS ON THE STRUCTURE AND FUNCTION OF A

CELL STRUCTURE IS THE BASIC CHARACTERISTIC THAT DECIDES THE CELLULARITY OF A

BE CLASSIFIED. D ORGANISMS ORGANISM HAS A SIMPLE BODY STRUCTURE AND AN ANCIENT BODY DESI

WHICH HAVE NOT CHANGED MUCH OVER TIME. OR A HIGHER ORGANISM HAS A COMPLEX BODY STRUCTURE AND

WE CAN CONCLUDE THAT UNICELLULAR OR SIMPLE ORGANISMS GAVE RISE TO MULTICELLULAR O

STING ANIMALS AND PLANTS HAVE DEVELOPED BY A PROCESS OF GRADUAL A

PRIMITIVE OR SIMPLE ORGANISMS. THIS IS KNOWN AS EVOLUTION.

G TWO ORGANISMS DO YOU CONSIDER PRIMITIVE?

AS A SIMPLE BODY STRUCTURE AND AN ANCIENT BODY DESIGN OR FEATURES

. THEREFORE, AMOEBA IS A PRIMITIVE ORGANISM AS COMPARED TO

ON EARTH ARE CLASSIFIED INTO FIVE MAJOR GROUPS. THIS IS KNOWN AS

KINGDOM CLASSIFICATION. WHO PROPOSED THIS CLASSIFICATION AND WHAT

INGDOM IS THE HIGHEST LEVEL OF CLASSIFICATION AS PROPOSED BY LINNAEUS

SYSTEM OF CLASSIFICATION, BIOLOGIST R.H. WHITTAKER (IN 1969) PROPOSED A FIVE

ON OF LIVING ORGANISMS. POSED BY WHITTAKER ARE MONERA, PROTISTA, FUNGI,

OESE FURTHER DIVIDED MONERA INTO ARCHAEBACTERIA AND EUBACTERIA DEPENDING ON THE

ABLE TO INHABIT.

T CAME INTO EXISTENCE EARLIER OR

BECAUSE THEY ARE INDEPENDENT OF

RE AND FUNCTION OF AN

THE CELLULARITY OF AN

AN ANCIENT BODY DESIGN OR

TRUCTURE AND

E TO MULTICELLULAR OR

PROCESS OF GRADUAL AND

FEATURES, WHICH

ISM AS COMPARED TO

HIS IS KNOWN AS

SSIFICATION AND WHAT ARE THE FIVE

INNAEUS. BASED ON

PROPOSED A FIVE-

RIA DEPENDING ON THE

5

WHAT ARE THE CHARACTERIST

FUNDAMENTAL CHARACTERISTICS USED FOR CLAS

BASED ON THE PRESENCE OR ABSENCE OF

DIVIDED INTO TWO BROAD CATEGORIES OF

ON THE BASIS OF CELLULARITY

UNICELLULAR EUKARYOTES FORM THE

AS AMOEBA, PARAMECIUM, DIATOMS

THE PRESENCE OR ABSENCE OF

PLANTS AND FUNGI ARE BOTH MULTICELLULAR

FUNGI AND PLANTS INTO SEPARATE KINGDOMS

FUNGI HAVE A SAPROPHYTIC MODE OF NUTRITIO

NUTRITION. SOME COMMONLY KNOWN F

ARE PENICILLIUM, ASPERGILLUS

CELL WALL IS ABSENT IN ANIMALS AND THEY H

BRANCH DIAGRAM REPRESENTING FIVE

LET US NOW STUDY THE CHARACTERISTIC FEATU

THE FIVE-KINGDOM CLASSIFICATION

KINGDOM MONERA SOME GENERAL FEATURES OF MONERANS ARE AS F

ABSENCE OF A WELL-DEFINED NUCLEUS OR M

ARE THE CHARACTERISTICS OF LIVING ORGANISMS ON WHICH THE CLASSIFICATION WAS MADE

ISTICS USED FOR CLASSIFICATION OF LIVING ORGANISMS: OR ABSENCE OF MEMBRANE-BOUND ORGANELLES, ALL LIVING ORGANISMS

AD CATEGORIES OF EUKARYOTES AND PROKARYOTES. LARITY, WE CAN DIVIDE EUKARYOTES AS UNICELLULAR AND MULTICELLULAR

S FORM THE KINGDOM PROTISTA. IT INCLUDES PROTOZOA SUCH

DIATOMS, AND SLIME MOULDS. CE OF THE CELL WALL IS TAKEN AS THE CRITERIA FOR FURTHER CLASSIFIC

BOTH MULTICELLULAR, EUKARYOTIC, AND HAVE A CELL WALL. WO SEPARATE KINGDOMS ON THE BASIS OF THEIR MODES OF NUTRITION

TIC MODE OF NUTRITION WHEREAS PLANTS HAVE AN AUTOTROPHIC MOD

OME COMMONLY KNOWN FUNGI

SPERGILLUS, PUCCINIA, ALBUGO,USTILAGO, ETC. N ANIMALS AND THEY HAVE A HETEROTROPHIC MODE OF NUTRITION

ENTING FIVE-KINGDOM CLASSIFICATION

CHARACTERISTIC FEATURES OF ORGANISMS BELONGING TO VARIOUS GR

GDOM CLASSIFICATION.

OF MONERANS ARE AS FOLLOWS. DEFINED NUCLEUS OR MEMBRANE-BOUND ORGANELLES

SSIFICATION WAS MADE?

ALL LIVING ORGANISMS ARE

AND MULTICELLULAR. SUCH

OR FURTHER CLASSIFICATION.

WE CAN SEPARATE

R MODES OF NUTRITION. E AN AUTOTROPHIC MODE OF

MODE OF NUTRITION.

ONGING TO VARIOUS GROUPS OF

6

ABSENCE OF MULTICELLULAR BODY DESIGNS [ALL ARE UNICELLULAR.] PRESENCE OR ABSENCE OF A CELL WALL AUTOTROPHIC OR HETEROTROPHIC MODE OF NUTRITION THIS KINGDOM INCLUDES MAINLY BACTERIA AND BLUE-GREEN ALGAE (CYANOBACTERIA). ALL PROKARYOTES ARE GROUPED UNDER KINGDOM MONERA. THEREFORE, THE OTHER FOUR KINGDOMS

INCLUDE ONLY EUKARYOTES. ON THE BASIS OF CELLULARITY, WE CAN DIVIDE EUKARYOTES AS UNICELLULAR AND MULTICELLULAR. UNICELLULAR EUKARYOTES FORM KINGDOM PROTISTA. KINGDOM PROTISTA SOME GENERAL FEATURES ARE AS FOLLOWS. THEY ARE UNICELLULAR EUKARYOTIC ORGANISMS. THEY CAN BE AUTOTROPHIC OR HETEROTROPHIC. SOME MEMBERS HAVE CILIA OR FLAGELLA, WHICH HELPS IN LOCOMOTION. IT INCLUDES PROTOZOA SUCH AS AMOEBA AND PARAMECIUM, DIATOMS, AND SLIME MOULDS. KINGDOM PROTISTA INCLUDES ALL UNICELLULAR EUKARYOTES. NOW, LET US LOOK AT THE CLASSIFICATION

OF MULTICELLULAR EUKARYOTES. THE PRESENCE OR ABSENCE OF THE CELL WALL IS TAKEN AS THE CRITERIA

FOR FURTHER CLASSIFICATION AMONG MULTICELLULAR EUKARYOTES. CAN YOU NAME ANY MULTICELLULAR EUKARYOTES CONTAINING A CELL WALL? PLANTS AND FUNGI ARE BOTH MULTICELLULAR, EUKARYOTIC ORGANISMS HAVING A CELL WALL. WE CAN SEPARATE FUNGI AND PLANTS INTO SEPARATE KINGDOMS ON THE BASIS OF THEIR MODES OF

NUTRITION. FUNGI HAVE A SAPROPHYTIC MODE OF NUTRITION WHEREAS PLANTS HAVE AN AUTOTROPHIC

MODE OF NUTRITION. KINGDOM FUNGI SOME GENERAL FEATURES OF KINGDOM FUNGI ARE AS FOLLOWS. THEY ARE MULTICELLULAR EUKARYOTIC ORGANISMS. THEIR BODY CONSISTS OF MYCELIUM, WHICH IS MADE UP OF MULTICELLULAR FILAMENTOUS HYPHAE. THEIR CELL WALLS ARE MADE UP OF TOUGH, COMPLEX SUGAR CALLED CHITIN. THEY ARE SAPROPHYTES, WHICH FEED ON DEAD ORGANIC MATERIAL. SOME COMMONLY KNOWN FUNGI ARE PENICILLIUM, ASPERGILLUS, PUCCINIA, ALBUGO, AND USTILAGO. SOME INTERESTING FACTS: DID YOU KNOW THAT SOME FUNGI LIVE IN A MUTUALLY BENEFICIAL RELATIONSHIP WITH CYANOBACTERIA

TO FORM LICHENS? THIS KIND OF A RELATIONSHIP IS CALLED SYMBIOSIS. THESE LICHENS GROW VERY SLOWLY. A COLONY OF LICHENS IN THE ARCTIC TAKES AROUND 1,000 YEARS

TO GROW TWO INCHES. KINGDOM PLANTAE SOME GENERAL FEATURES OF KINGDOM PLANTAE ARE AS FOLLOWS. THEY ARE MULTICELLULAR EUKARYOTIC ORGANISMS. CELL WALL IS MADE UP OF CELLULOSE, AND NOT CHITIN UNLIKE THAT OF FUNGI. MOST PLANT CELLS CONTAIN CHLOROPHYLL PIGMENTS. HENCE, THEY ARE AUTOTROPHIC.

7

THEY ARE NON-MOTILE. KINGDOM ANIMALIA SOME GENERAL FEATURES OF KINGDOM

THEY ARE MULTICELLULAR EUKARYOTES

CELL WALL IS ABSENT IN THEM

CHLOROPLAST IS ABSENT IN ANIMAL CELLS

KINGDOM PLANTAE YOU MUST HAVE SEEN DIFFERENT KINDS OF TRE

ALL THESE TREES SHOW COMMON CHARACTERISTI

ARE THEY DIFFERENT FROM EACH OTHER

DIVISIONS BASED ON THE CHARACTERISTICS O

THE PLANT KINGDOM IS CLASSIFIED INTO FIVE

GYMNOSPERMAE, AND ANGIOSPERMAE

WHAT ARE THE CHARACTERISTIC FEATURES OF M

EXPLORE EVERY DIVISION OF THE PLANT KING

DIVISION THALLOPHYTA GENERAL FEATURES OF THALLOPHYTA

THE PLANT BODY IS NOT DIFFERENTIATED INTO

THESE PLANTS ARE MOSTLY AQUATIC

SPORES ARE PRODUCED AS A RESULT OF FERTIL

A FEW EXAMPLES ARE SPIROGYRA

THALLOPHYTES DIVISION BRYOPHYTA GENERAL FEATURES OF BRYOPHYTES

THE PLANT BODY IS GENERALLY DIFFERENTIATE

INSTEAD OF TRUE ROOTS, RHIZOIDS ARE PRESENT

SPECIALIZED VASCULAR TISSUES FOR

NAKED EMBRYOS CALLED SPORES

OF KINGDOM ANIMALIA ARE AS FOLLOWS. R EUKARYOTES.

N THEM. IN ANIMAL CELLS. HENCE, THEY HAVE A HETEROTROPHIC MODE OF NUTRIT

FFERENT KINDS OF TREES GROWING AROUND YOUR HOUSE OR I

COMMON CHARACTERISTICS AND CAN BE CLASSIFIED UNDER ONE CATEG

ROM EACH OTHER? THE PLANT KINGDOM IS FURTHER DIVIDED INTO

HE CHARACTERISTICS OF DIFFERENT TYPES OF PLANTS. CLASSIFIED INTO FIVE DIVISIONS – THALLOPHYTA, BRYOPHYTA

NGIOSPERMAE. RISTIC FEATURES OF MEMBERS BELONGING TO THESE DIVISIONS

ON OF THE PLANT KINGDOM IN DETAIL.

HALLOPHYTA: DIFFERENTIATED INTO ROOTS, STEMS, AND LEAVES. LY AQUATIC. S A RESULT OF FERTILIZATION.

PIROGYRA, CLADOPHORA, ULVA, PORPHYRA, AND CHARA.

RYOPHYTES: ERALLY DIFFERENTIATED INTO STEM AND LEAF-LIKE STRUCTURES

RHIZOIDS ARE PRESENT. TISSUES FOR THE CONDUCTION OF WATER ARE ABSENT (E.G. XYLEM

SPORES ARE PRODUCED AS A RESULT OF FERTILIZATION.

OPHIC MODE OF NUTRITION.

UR HOUSE OR IN A GARDEN. DO

FIED UNDER ONE CATEGORY, OR

FURTHER DIVIDED INTO DIFFERENT

RYOPHYTA, PTERIDOPHYTA,

THESE DIVISIONS? LET US

LIKE STRUCTURES.

XYLEM).

8

BRYOPHYTES IT INCLUDES MOSSES, RICCIA, DO YOU KNOW THAT BRYOPHYTES ARE CALLED

BRYOPHYTES ARE CALLED AMPHIBIAN

FOR GROWTH. THEY ARE NOT COMPLETE

SPECIALIZED VASCULAR TISSUES

DIVISION PTERIDOPHYTA GENERAL FEATURES OF PTERIDOPHYTES

THE PLANT BODY IS DIFFERENTIATED INTO ROO

THEY HAVE SPECIALIZED, CONDUCTING TISSUES F

SUBSTANCES. THEY HAVE INCONSPICUOUS OR LESS DIFFER

THEY PRODUCE NAKED EMBRYOS CALLED

SOME EXAMPLES OF PTERIDOPHYTES ARE FERNS

PTERIDOPHYTES DIVISION GYMNOSPERMAE GYMNOSPERMS ARE SEED-BEARING

ANGIOSPERMS. THEY INCLUDE PLANTS S

GYMNOSPERMS

ANTHOCEROS, MARCHANTIA, ETC. RYOPHYTES ARE CALLED AMPHIBIANS OF THE PLANT KINGDOM?

ARE CALLED AMPHIBIANS OF THE PLANT KINGDOM BECAUSE THEY REQUIRE A MOIST HABITAT

HEY ARE NOT COMPLETELY AQUATIC OR TERRESTRIAL. THIS IS BECAUSE THEY

TISSUES. THEREFORE, THEY CANNOT SURVIVE IN TERRESTRIAL HABIT

TERIDOPHYTES: FERENTIATED INTO ROOTS, STEMS, AND LEAVES.

CONDUCTING TISSUES FOR THE CONDUCTION OF WATER AND OTHER

CUOUS OR LESS DIFFERENTIATED REPRODUCTIVE ORGANS. BRYOS CALLED SPORES.

IDOPHYTES ARE FERNS, MARSILEA, EQUISETUM, AND LYCOPODIUM

BEARING, NON-FLOWERING PLANTS. THEY ARE MORE PRIMITI

HEY INCLUDE PLANTS SUCH AS PINUS, CEDAR, FIR, JUNIPER, AND CYCAS

WHY? IRE A MOIST HABITAT

HIS IS BECAUSE THEY DO NOT HAVE

IN TERRESTRIAL HABITATS.

WATER AND OTHER

YCOPODIUM.

HEY ARE MORE PRIMITIVE THAN

YCAS.

9

SOME GENERAL FEATURES OF GYMNOSPERMS ARE

THEY ARE PERENNIAL PLANTS THAT GROW AS WOODY T

VASCULAR BUNDLES ARE PRESENT

FLOWERS ARE ABSENT. INSTEAD

SEEDS ARE PRODUCED NAKED I

DIVISION ANGIOSPERMAE ANGIOSPERMS ARE FLOWERING PLANTS

AROUND 2, 50,000 SPECIES OF PLANTS

PLANTS. GENERAL FEATURES OF ANGIOSPERMS

THESE PLANTS BEAR FLOWERS THAT CONSIST OF

GYNOECIUM. SEEDS DEVELOP INSIDE THE OVARY

THE EMBRYOS INSIDE THE SEEDS CONTAIN COTY

LEAVES. WHEN THE SEEDS GERMIN

PHOTOSYNTHESIZING. THESE COTYLEDONS

COTYLEDONS

LET US SUMMARIZE THE DIFFERENT DIVISIONS

OF GYMNOSPERMS ARE AS FOLLOWS. THAT GROW AS WOODY TREES OR BUSHY SHRUBS.

PRESENT, BUT XYLEM LACKS VESSELS AND PHLOEM LACKS COMPANION CELLS

NSTEAD, MALE AND FEMALE CONES ARE FOUND. KED I.E., THEY ARE NOT ENCLOSED INSIDE THE FRUIT.

RE FLOWERING PLANTS IN WHICH SEEDS ARE ENCLOSED INSIDE THE FRUIT

SPECIES OF PLANTS. THEY ARE THE MOST RECENT AND HIGHLY EVOLV

NGIOSPERMS: WERS THAT CONSIST OF FOUR WHORLS – CALYX, COROLLA, ANDROECIUM

THE OVARY, WHICH DEVELOPS INTO A FRUIT. E SEEDS CONTAIN COTYLEDONS. THE COTYLEDONS ARE CALLED EMBRYONIC

HEN THE SEEDS GERMINATE, THE LEAVES COME OUT. THEY TURN GREEN AND S

HESE COTYLEDONS (INSIDE A SEED) MAY BE ONE OR TWO IN NUMBER

DIFFERENT DIVISIONS OF KINGDOM PLANTAE.

COMPANION CELLS.

THE FRUIT. THEY INCLUDE

ENT AND HIGHLY EVOLVED GROUP OF

ANDROECIUM, AND

LLED EMBRYONIC

HEY TURN GREEN AND START

NUMBER.

10

BRANCH DIAGRAM SHOWING THE CLASSIFICATION

SOME INTERESTING FACTS: DID YOU KNOW THAT IN DICOT TREES

INCREASE IN GIRTH BY FORMING A NEW LAYER

TO PEEL OFF? MONOCOT TREES, SUCH AS PALM

FORMED IN THEM. LET US UNDERSTAND THE DIFFERENCE BETWEEN D

PLACE A FEW SEEDS OF BEAN AND CORN IN WAT

MAKING IT EASIER FOR THE SEED COAT TO

REMOVE THE SEED COAT FROM THE SOAKED SEED

PARTS USING A TOOTHPICK. TAKE THE CORN SEEDS AND REMOVE THEIR SEED

WHICH OF THE TWO SEEDS IS A M

CORN IS A MONOCOT BECAUSE ITS SEED CANNOT

G THE CLASSIFICATION OF PLANTS

DICOT TREES SUCH AS MANGO, GUAVA ETC., THE TRUNK AND OLD BR

FORMING A NEW LAYER EACH YEAR, WHICH REPLACES THE OLD BARK AND CAUSES I

SUCH AS PALM, COCONUT ETC., DO NOT INCREASE IN GIRTH BECAUSE N

DIFFERENCE BETWEEN DICOTS AND MONOCOTS BY SPLITTING SEEDS

BEAN AND CORN IN WATER FOR ONE NIGHT. THIS WILL MAKE THEM T

THE SEED COAT TO COME OFF. THE SEEDS CAN THEN BE SPLIT EASILY

FROM THE SOAKED SEEDS OF BEANS. NOW, SPLIT THE BEANS INTO

ND REMOVE THEIR SEED COAT. TRY TO SPLIT THE CORN SEED INTO HALVES

THE TWO SEEDS IS A MONOCOT?

AUSE ITS SEED CANNOT BE SPLIT INTO TWO EQUAL PARTS.

THE TRUNK AND OLD BRANCHES

LD BARK AND CAUSES IT

E IN GIRTH BECAUSE NO NEW WOOD IS

Y SPLITTING SEEDS. HIS WILL MAKE THEM TENDER,

SPLIT EASILY. SPLIT THE BEANS INTO TWO EQUAL

SEED INTO HALVES.

11

KINGDOM ANIMALIA THE ANIMAL KINGDOM CONSISTS OF MULTICELLU

HETEROTROPHIC MODE OF NUTRITION

LET US FIRST STUDY ABOUT THE CHARACTERISTIC FE

ANIMALIA I.E. PORIFERA, COELENTERATA

ARTHROPODA, AND ECHINODERMATA

PHYLUM PORIFERA GENERAL FEATURES OF PHYLUM

THEY ARE MOSTLY MARINE AND NON

THEY ARE MOSTLY FOUND ATTACHED TO ROCKS

THEY SHOW CELLULAR LEVEL OF ORGANIZATION

ORGANS.

CNIDARIA.

CALLED ECTODERMAND THE INNER LAYER IS CA

MOST OF THESE ANIMALS HAVE RADIAL SYM

SOME INTERESTING FACTS: DID YOU KNOW THAT THERE ARE MORE THAN

THE GREAT BARRIER REEF IS THE LARGEST C

3,000 INDIVIDUAL CORALS EXTENDING AROUND

PHYLUM PLATYHELMINTHES PLATYHELMINTHES ARE CALLED FLATWORMS BECA

THEREFORE, THEY APPEAR LEAF

NSISTS OF MULTICELLULAR EUKARYOTIC ORGANISMS, HAVING A

F NUTRITION. HE CHARACTERISTIC FEATURES OF THE FIRST EIGHT PHYLA OF KINGD

OELENTERATA, PLATYHELMINTHES, NEMATODA, ANNELIDA

CHINODERMATA.

HYLUM PORIFERA: ND NON-MOTILE.

ATTACHED TO ROCKS. VEL OF ORGANIZATION. THEIR BODY IS NOT ORGANIZED INTO TISSUES

THEIR BODIES ARE POROUS. THEIR BODY HAS HOLES

ALL OVER, WHICH ALLOWS THE CIRCULATION OF WATER

THROUGHOUT THE BODY AND BRING IN FOOD AND

PHYLUM COELENTERATA IT INCLUDES AQUATIC ANIMALS LIKE HYDRA

CORALS ETC. PHYLUM COELENTERATA IS ALSO

GENERAL FEATURES OF COELENTERATES: THEY ARE EXCLUSIVELY MARINE ANIMALS. BODY CAVITY IS ABSENT. THEY HAVE A TISSUE LEVEL OF ORGANIZATION AND LACK ORGANS AND

ORGAN SYSTEMS. THEIR BODY IS MADE UP OF TWO LAYERS OF CELLS; THE OUTER LAYER IS

HE INNER LAYER IS CALLED ENDODERM. HAVE RADIAL SYMMETRY.

THERE ARE MORE THAN 2,000 CORAL REEFS IN THE WORLD? EEF IS THE LARGEST CORAL REEF OF THE WORLD. IT IS COMPOSED OF ARO

TENDING AROUND 2,600 KM.

ALLED FLATWORMS BECAUSE THEIR BODIES ARE DORSOVENTRALLY FLATT

THEY APPEAR LEAF-LIKE OR RIBBON-LIKE CREATURES. THEY INCLUDE FASCIOLA

HEPATICA(LIVER FLUKE), TAENIA

SOLIUM (TAPEWORM), SCHISTOSOMA (BLOOD FLUKE),GENERAL FEATURES OF PLATYHELMINTHES: THEY ARE MOSTLY PARASITIC (E.G. TAPEWORM, LIVER FLUKES

HOWEVER, SOME MAY BE FREE LIVING (E.G. PLANARIA

TRUE BODY CAVITY IS ABSENT. THEY SHOW BILATERAL SYMMETRY. THEY SHOW AN ORGAN SYSTEM LEVEL OF ORGANIZATION

HAVING A

EIGHT PHYLA OF KINGDOM

NNELIDA, MOLLUSCA,

ANIZED INTO TISSUES AND

HEIR BODY HAS HOLES OR PORES

CULATION OF WATER

ND BRING IN FOOD AND OXYGEN.

YDRA, SEA ANEMONE, OELENTERATA IS ALSO KNOWN AS

AND LACK ORGANS AND

THE OUTER LAYER IS

T IS COMPOSED OF AROUND

DORSOVENTRALLY FLATTENED.

ASCIOLA

), PLANARIA ETC.

LIVER FLUKES).

LANARIA).

TION.

12

IN ADDITION TO ECTODERM AND ENDODERM

THESE TWO LAYERS. THEREFORE

DO YOU KNOW THAT ONE OF THE FIRST ANTI

IN 1959, AN ANTI-CANCER DRUG

I.E. CRYPTOTHETHYA CRYPTA. PHARMACEUTICAL COMPANIES AS THEY PRODUCE

INFLAMMATION, DIABETES, AND GASTROINTESTINAL

DO YOU KNOW WHAT CAUSES LIVER ROT DISEASE

LIVER FLUKE FOUND IN THE LIVER AND BILE D

BREAKDOWN OF LIVER CELLS. TANIMALS AND CAN BE FATAL. PHYLUM NEMATODA IT INCLUDES ROUNDWORMS, WHICH ARE COMMONLY C

NEMATODA ARE ASCARIS, WUCHERERIA

EARTHWORMS AND LEECHES. T

TRUE BODY CAVITY OR COELOM IS PRESENT

SOME INTERESTING FACTS: DID YOU KNOW THAT EARTHWORMS DO NOT HA

LIGHT? THESE RECEPTORS HELP

EARTHWORMS ARE ONLY FOUND IN HUMID CONDIT

THEY HAVE A COVERING OF MUCUS

RM AND ENDODERM, A LAYER OF CELLS CALLED MESODERM IS FOUN

HEREFORE, THESE ARE TRIPLOBLASTIC ANIMALS. OF THE FIRST ANTI-CANCER DRUGS WAS ISOLATED FROM A SPONGE

CER DRUG (CYTOSINE ARABINOSIDE) WAS EXTRACTED FROM A SEA SPONGE

RECENTLY SPONGESHAVE RECEIVED MUCH ATTENTIONFROM THE

NIES AS THEY PRODUCE MANY CHEMICALS, WHICH HELP IN FIGHTI

AND GASTROINTESTINAL AILMENTS. ES LIVER ROT DISEASE?

THE LIVER AND BILE DUCTS OF SHEEP AND GOATS CAUSES THE COMPL

THIS IS KNOWN AS LIVER ROT DISEASE. THIS IS A SERIOUS DIS

WHICH ARE COMMONLY CALLED NEMATODES. SOME MEMBERS OF PHYLU

UCHERERIA, ANCYLOSTOMA ETC. GENERAL FEATURES OF PHYLUM

THEY ARE BILATERALLY SYMMETRICAL AND

TRIPLOBLASTIC. THEY HAVE A CYLINDRICAL BODY WITH

TAPERING ENDS. THEY HAVE AN ORGAN SYSTEM LEVEL OF

ORGANIZATION. THEY ARE PARASITIC ANIMALS

FALSE BODY CAVITY OR PSEUDOCOELOM IS

PRESENT. PHYLUM ANNELIDA IT INCLUDES SEGMENTED WORMS LIKE

THEY OCCUR IN BOTH TERRESTRIAL AND AQUATIC ENVIRONMENTS

MAY BE FREE-LIVING OR PARASITIC

GENERAL FEATURES OF A

THEY MAY BE FREE-LIVING OR PARASITIC

THEY ARE BILATERALLY

AND THEIR BODY IS SEGMENTED

THEY HAVE THREE GERM

THEY ARE TRIPLOBLAST

THEY POSSESS TRUE ORG

THEIR BODY STRUCTURE

OELOM IS PRESENT (SCHIZOCOELOM).

EARTHWORMS DO NOT HAVE EYES, BUT THEY HAVE LIGHT RECEPTORS TO SENSE

HESE RECEPTORS HELP THEM DIFFERENTIATE BETWEEN LIGHT AND DARKNESS. OUND IN HUMID CONDITIONS BECAUSE THEY RESPIRE THROUGH THEIR

OF MUCUS, WHICH ALLOWS DISSOLVED OXYGEN TO MOVE INTO BLOOD

LED MESODERM IS FOUND BETWEEN

LATED FROM A SPONGE? SEA SPONGE

IONFROM THE

WHICH HELP IN FIGHTING INFECTION,

ATS CAUSES THE COMPLETE

HIS IS A SERIOUS DISEASE IN

OME MEMBERS OF PHYLUM

HYLUM NEMATODA: SYMMETRICAL AND

AL BODY WITH

STEM LEVEL OF

IMALS. PSEUDOCOELOM IS

WORMS LIKE

C ENVIRONMENTS. THEY

LIVING OR PARASITIC. ENERAL FEATURES OF ANNELIDS:

LIVING OR PARASITIC. HEY ARE BILATERALLY SYMMETRICAL,

GMENTED. HEY HAVE THREE GERM LAYERS. THUS,

THEY ARE TRIPLOBLASTIC ANIMALS. HEY POSSESS TRUE ORGANS INSIDE

THEIR BODY STRUCTURES.

RECEPTORS TO SENSE

SPIRE THROUGH THEIR SKIN.

TO BLOOD.

13

PHYLUM ARTHROPODA: IT IS THE LARGEST PHYLUM OF THE ANIMAL KI

INCLUDES CRABS, PRAWNS, INSECTS

PRESENCE OF A DISTINCT HEAD

JOINTED LEGS FOR MOVING AROUND

OPEN CIRCULATORY SYSTEM I.PHYLUM MOLLUSCA: IT IS THE SECOND LARGEST PHYLUM AFTER ART

OCTOPUS, PILA,MUSSEL, UNIO

GENERAL FEATURES OF MOLLUSCA

THEY ARE MOSTLY FOUND IN SEAS

THEIR BODY IS NOT SEGMENTED LIKE ANNEL

THEY SHOW BILATERAL SYMMETRY

THEY HAVE AN OPEN CIRCULATORY SYSTEM AND

THEIR BODY IS MADE UP OF THREE GERM LAYERS

THEY HAVE A DISTINCT FOOT FOR MOVING

PHYLUM ECHINODERMATA: THIS PHYLUM INCLUDES ONLY MARINE ANIMALS

LUM OF THE ANIMAL KINGDOM AND INCLUDES MORE THAN 9, 00,000INSECTS, SPIDERS, SCORPIONS, CENTIPEDES, MILLIPEDES ETC

GENERAL FEATURES OF A

THEY SHOW BILATERAL S

TRIPLOBLASTIC ANIMALS

SEGMENTED BODY LIKE T

ANNELIDS. SCHIZOCOELOM IS PRESE

ADVANCED FEATURES OF

ARTHROPODA: T HEAD. NG AROUND.

.E. BLOOD DOES NOT FLOW IN WELL DEFINED BLOOD VESSELS

EST PHYLUM AFTER ARTHROPODS. IT INCLUDES SNAIL, NIO ETC.

OLLUSCA: IN SEAS, BUT MAY BE FOUND IN FRESH WATER, OR ON LAND.

MENTED LIKE ANNELIDS AND ARTHROPODS. YMMETRY. CULATORY SYSTEM AND POSSESS KIDNEY-LIKE ORGANS FOR EXCR

OF THREE GERM LAYERS. THEREFORE, THEY ARE TRIPLOBLASTIC ANIMALS

FOOT FOR MOVING AROUND.

ONLY MARINE ANIMALS LIKE STARFISH, SEA URCHIN, SEA CUCUMBER ETC

00,000 SPECIES. IT

MILLIPEDES ETC. ENERAL FEATURES OF ARTHROPODS: HEY SHOW BILATERAL SYMMETRY.

ANIMALS. EGMENTED BODY LIKE THOSE OF

CHIZOCOELOM IS PRESENT. DVANCED FEATURES OF

D VESSELS.

.

LIKE ORGANS FOR EXCRETION. IC ANIMALS.

SEA CUCUMBER ETC.

14

GENERAL FEATURES OF ECHINODERMATA

THEY ARE EXCLUSIVELY FREE-LIVING MARINE ANIMAL

THEY MAY BE GLOBULAR OR CYLINDRICAL IN SH

THEY HAVE AN ORGAN SYSTEM L

THEIR BODY IS MADE UP OF THREE GERM LAYERS

IN LARVAL STAGES, THEY HAVE BILATERAL

THEIR BODY HAS A SPINY OUTER COVERING

THEY USE A POWERFUL WATER

THUS, THE ANIMAL KINGDOM C

BRANCH DIAGRAM SHOWING THE ANIMAL KINGDOM

DO YOU KNOW WHAT VERMICULTURE IS

CHINODERMATA:

LIVING MARINE ANIMALS. OR CYLINDRICAL IN SHAPE.

VE AN ORGAN SYSTEM LEVEL OF ORGANIZATION. OF THREE GERM LAYERS. THEREFORE, THEY ARE TRIPLOBLASTIC ANIMALS

THEY HAVE BILATERAL SYMMETRY AND AS ADULTS, THEY HAVE RADIAL SYM

Y OUTER COVERING MADE UP OF CALCIUM CARBONATE. ATER-DRIVEN TUBE SYSTEM FOR MOVING AROUND.

THE ANIMAL KINGDOM CLASSIFICATION CAN BE SUMMARISED AS FOLLOWS:

G THE ANIMAL KINGDOM CLASSIFICATION ICULTURE IS?

IC ANIMALS. THEY HAVE RADIAL SYMMETRY.

15

VERMICULTURE REFERS TO THE TECHNI

EARTHWORMS ARE THEN SUPPLIED TO FISHERME

LABORATORIES.

SUB-PHYLUM PROTOCHORDATA AND C

SUB-PHYLUM PROTOCHORDATA

KINGDOM ANIMALIA IS DIVIDED INTO CHORDATES AND NON

ABSENCE OF NOTOCHORD. NON-CHORDATES DO NOT POS

CHORDATA POSSESS NOTOCHORD.

THEREFORE, CAN ALL ANIMALS BE CLASSIFIED AS CHORDAT

SOME ANIMALS LIKE BALANOGLOSSUS H

WHICH IS NOT PRESENT AT ALL STAGES IN THE

BODY. THEREFORE, THESE ANIMALS ARE KEPT IN A

AS THE NAME SUGGESTS, ‘PROTO’ MEANS PRIMITIVE AND

ANIMALS ARE PRIMITIVE CHORDATES, AND HAVE GIVEN RISE

GENERAL FEATURES OF PROTOCHORDATA

• THEY ARE EXCLUSIVELY MARINE ANIMALS

• THEY SHOW AN ORGAN SYSTEM LEVEL OF ORGANI

• THEIR BODY IS NOT SEGMENTED

• BODY CAVITY IS ENTEROCOELOM

REFERS TO THE TECHNIQUE OF RAISING AND BREEDING EARTHWORMS.

SUPPLIED TO FISHERMEN, POULTRY WORKERS, ZOOS, AND VARIOUS BIOLOGY

CHORDATA

CHORDATES AND NON-CHORDATES ON THE BASIS OF THE PRESENCE O

CHORDATES DO NOT POSSESS A NOTOCHORD, WHEREAS ALL MEMBERS

LASSIFIED AS CHORDATES AND NON-CHORDATES? THE ANSWER IS

HERDMANIA, AMPHIOXUS, SACCOGLOSSUS ETC. HAVE A NOTOCHORD

AT ALL STAGES IN THEIR LIFECYCLE, NOR DOES IT RUN THE ENTIRE LENGTH OF AN

IMALS ARE KEPT IN A SEPARATE SUB-PHYLUM NAMED PROTOCHORDATA

MEANS PRIMITIVE AND ‘CHORDATA’ IS CHORDATES. THIS MEANS THAT THESE

AND HAVE GIVEN RISE TO MODERN DAY CHORDATES.

ROTOCHORDATA:

MARINE ANIMALS. THEY OFTEN LIVE IN BURROWS.

STEM LEVEL OF ORGANIZATION, AND ARE TRIPLOBLASTIC.

MENTED, AND IS BILATERALLY SYMMETRICAL.

COELOM.

• NOTOCHORD IS PRESENT IN SOME STAGE

SOME INTERESTING FACTS:

• DID YOU KNOW THAT IN HERDMANIA

NOTOCHORD APPEARS ONLY IN THE TAIL OF TH

DISAPPEARS IN THE ADULTS?

• IN AMPHIOXUS, THE NOTOCHORD EXTEND

ANTERIOR END OF THE BODY, AND IT IS PRESENT TH

THEIR LIFE.

SUB-PHYLUM VERTEBRATA

THE MEMBERS OF SUB-PHYLUM VERTEBRATA ARE ADVANC

THESE

AND VARIOUS BIOLOGY

IS OF THE PRESENCE OR

WHEREAS ALL MEMBERS OF PHYLUM

HE ANSWER IS NO.

HAVE A NOTOCHORD,

ENTIRE LENGTH OF AN ANIMAL’S

ROTOCHORDATA.

HIS MEANS THAT THESE

RESENT IN SOME STAGES.

ERDMANIA, THE

LY IN THE TAIL OF THE LARVA AND

THE NOTOCHORD EXTENDS UNTIL THE

AND IT IS PRESENT THROUGHOUT

ERTEBRATA ARE ADVANCED

16

CHORDATES. WHICH FEATURES MAKE A

FEATURES OF THE MEMBERS OF THE SUB

GENERAL FEATURES OF VERTEBRATA:

• NOTOCHORD IS PRESENT ONLY IN THE EMBRYONI

• IN ADULTS, THE NOTOCHORD IS REP

RING-LIKE BONES CALLED VERTEBRAE

• THEY HAVE A MUSCULAR HEART WITH TWO

• THEY ARE BILATERALLY SYMMETRICAL AND TRIPL

• THE BODY CAVITY IS ENTEROCOELOM

• THEY HAVE PAIRED GILL POUCHES

FISHES, BIRDS, CROCODILES, FROGS, AND MONKEYS POSSESS

ARE VERTEBRATES. HOWEVER, DO THEY SHOW THE SAM

CLASSIFIED? LET US EXPLORE THE CLASSIFICATION OF HIGH

THE SUB-PHYLUM VERTEBRATA IS FURTHER

CLASSIFICATION OF VERTEBRATES INTO FIVE C

(I) CLASS PISCES

HICH FEATURES MAKE AN ANIMAL A VERTEBRATE? LET US STUDY ABOUT THE CHARACTERISTIC

ERS OF THE SUB-PHYLUM VERTEBRATA.

ONLY IN THE EMBRYONIC STAGE.

THE NOTOCHORD IS REPLACED BY A VERTEBRAL COLUMN CONSISTING OF

RTEBRAE.

HEART WITH TWO, THREE, OR FOUR CHAMBERS.

YMMETRICAL AND TRIPLOBLASTIC.

TEROCOELOM.

POUCHES.

AND MONKEYS POSSESS A VERTEBRAL COLUMN, AND THUS

DO THEY SHOW THE SAME FEATURES OR CHARACTERISTICS? HOW ARE THEY

ASSIFICATION OF HIGHER ANIMALS.

ERTEBRATA IS FURTHER DIVIDED INTO FIVE CLASSES.

TEBRATES INTO FIVE CLASSES

E CHARACTERISTIC

AND THUS

W ARE THEY

17

THIS CLASS INCLUDES FISHES LIKE SCOLIODON, TUNA, ROHU, SHARK ETC. THESE ANIMALS MOSTLY LIVE IN WATER.

HENCE, THEY HAVE SPECIAL ADAPTIVE FEATURES TO LIVE IN WATER LIKE A STREAMLINED BODY AND TAIL FOR

MOVEMENT.

GENERAL FEATURES OF CLASS PISCES:

• THEY ARE EXCLUSIVELY AQUATIC ANIMALS.

• THEIR SKIN IS COVERED WITH SCALES.

• THEY OBTAIN OXYGEN DISSOLVED IN WATER WITH THE HELP OF GILLS.

• THE HEART IS TWO CHAMBERED.

• THEY LAY EGGS.

• THEY ARE COLD-BLOODED ANIMALS.

CARTILAGINOUS FISHES: THE SKELETON OF THESE FISHES ARE MADE ENTIRELY OF CARTILAGE.

SCOLIODON, TORPEDO, AND SHARKS ARE EXAMPLES OF CARTILAGINOUS FISHES.

BONY FISHES:THE SKELETON OF THESE FISHES IS PARTLY OR WHOLLY COMPOSED OF BONES.

LABEO ROHITA OR ROHU, SEA HORSE, AND ANABAS ARE EXAMPLES OF BONY FISHES.

(II) CLASS AMPHIBIA

IT INCLUDES FROGS, TOADS, AND SALAMANDERS. THESE ANIMALS ARE COMMONLY KNOWN AS AMPHIBIANS.

GENERAL FEATURES OF AMPHIBIANS:

• THE ADULTS ARE TERRESTRIAL. THEY WERE THE FIRST VERTEBRATES TO OCCUPY LAND.

• THEY LIVE IN DAMP PLACES.

• THE ADULTS RESPIRE THROUGH LUNGS OR SKIN, AND THE LARVAE RESPIRE THROUGH GILLS.

• THEY LAY EGGS IN WATER.

• THEY ARE COLD-BLOODED ANIMALS.

• THEY HAVE A THREE-CHAMBERED HEART.

• THE SKIN HAS MUCUS GLANDS AND SCALES ARE ABSENT.

WHY DO YOU THINK ANIMALS LIKE FROGS, TOADS, AND SALAMANDERS ARE CALLED AMPHIBIANS?

18

IN GREEK, ‘AMPHI’ MEANS TWO, AND ‘BIOS’ MEANS LIFE. IT MEANS THAT THESE ANIMALS HAVE A DUAL MODE OF

LIFE. THEREFORE, THEY ARE CALLED AMPHIBIANS.

LET US STUDY THEIR DUAL MODE OF LIFE:

• THE LARVAL STAGE OF AMPHIBIANS IS FISH-LIKE AS THEY ARE AQUATIC. THEY HAVE A TAIL, WHICH AIDS

THEM IN SWIMMING AND THEY RESPIRE THROUGH GILLS.

• THEIR ADULT STAGE IS TERRESTRIAL. THEY MOVE WITH LIMBS AND RESPIRE THROUGH LUNGS AND SKIN.

(III) CLASS REPTILIA

IT INCLUDES REPTILES LIKE LIZARDS, SNAKES, TURTLES, CHAMELEONS ETC. THEY ARE CALLED REPTILES BECAUSE

THEY CREEP OR CRAWL ON LAND.

GENERAL FEATURES OF REPTILES:

• THEY ARE COLD-BLOODED ANIMALS.

• THE SKIN IS COVERED WITH SCALES.

• MOST OF THEM HAVE A THREE-CHAMBERED HEART, EXCEPT CROCODILES WHICH HAVE

A FOUR-CHAMBERED HEART.

• THEY LAY EGGS ON LAND.

• RESPIRATION IS THROUGH LUNGS.

SOME INTERESTING FACTS:

• DID YOU KNOW THAT KING COBRA IS THE LARGEST VENOMOUS SNAKE IN THE WORLD? IT IS

APPROXIMATELY 12 FEET LONG.

• MOST SNAKES SWALLOW THEIR PREY ALIVE. HOWEVER, POISONOUS SNAKES KILL THEIR PREY WITH THEIR

VENOM BEFORE SWALLOWING IT.

(IV) CLASS AVES

IT INCLUDES ALL BIRDS LIKE SPARROWS, PIGEONS, CROWS, PARROTS ETC.

GENERAL FEATURES OF BIRDS:

• MOST OF THEM HAVE FEATHERS.

• THEY POSSESS A BEAK.

• FORELIMBS ARE MODIFIED INTO WINGS FOR FLIGHT.

• HIND LIMBS ARE MODIFIED FOR WALKING AND CLASPING.

• BONES ARE HOLLOW.

19

• THE HEART IS FOUR-CHAMBERED.

• RESPIRATION IS THROUGH LUNGS.

• THEY ARE WARM-BLOODED ANIMALS.

• THEY LAY EGGS.

(V) CLASS MAMMALIA

IT INCLUDES A VARIETY OF ANIMALS THAT HAVE MILK-PRODUCING GLANDS (MAMMARY GLANDS) TO NOURISH

THEIR YOUNG ONES.

GENERAL FEATURES OF MAMMALS:

• THEY ARE FOUND IN A VARIETY OF HABITATS LIKE DESERTS, FORESTS, MOUNTAINS ETC.

• SOME OF THEM CAN ALSO FLY.

• THEY HAVE TWO PAIRS OF LIMBS FOR WALKING, RUNNING, OR FLYING.

• THEIR SKIN HAS HAIR AS WELL AS SWEAT GLANDS. HAIR ON THEIR BODY PROTECTS THEM IN WINTERS, AND

SWEAT GLANDS KEEP THEIR BODY COOL IN SUMMERS, SINCE THEY ARE WARM-BLOODED ANIMALS.

• RESPIRATION IS THROUGH LUNGS.

• THE HEART IS FOUR-CHAMBERED.

• THEY GIVE BIRTH TO YOUNG ONES, BUT SOME MAMMALS LAY EGGS.

EGG-LAYING MAMMALS ARE CALLED OVIPAROUS. THEY INCLUDE PLATYPUS, ECHIDNA ETC.

THE MAMMALS THAT GIVE BIRTH TO YOUNG ONES ARE CALLED VIVIPAROUS. THEY INCLUDE KANGAROOS, CAMELS,

RATS, DOGS, DOLPHINS, ELEPHANTS, HORSES, HUMANS, TIGERS ETC