BIOLOGY

CHAPTER4

ANIMALKINGDOM

BASIS OF CLASSIFICATION

Arrangement of cells

Body symmetry

Nature of coelom

Patterns of digestive

Circulatory systems

LEVEL OF ORGANISATION

Cellular level

Tissue level

Organ levelOrgan system

• SPONGES

• COELENTERATES

• PLATYHELMINTHES

Animal Categorized on the basis of symmetry

Radial SymmetryBilateral Symmetry

WHEN ANY PLANEPASSING THROUGH

THE CENTRAL AXIS OF THEBODY DIVIDES THE ORGANISM INTO

TWO IDENTICAL HALVES.

The body can be divided

Into identical leftAnd right halves

In only one Plane

SEGMENTATION

NOTOCHORDa. ROD LIKE STRUCTURE FORMED ON THE DORSOL SIDE

DURING ENBRYONIC DEVELOPMENT b. ANIMALS WITH NOTOCHORD ARE CALLED CHORDATES WHICH DO NOT PERFORM THIS STRUCTURE IS CALLED NON CHORDATES

a. THE BODY IS INTERNALLY AND EXTERNALLY DIVIDED INTO SEGMENTS .

b. IN EARTHWORM – THE BODY SHOWS METAMERIC SEGMENTATION - METAMERISM

Animals in which the cells are arranged in two Embroyonic layers , and external ectoderm and an Internal endoderm .

DIPLOBLASTIC AND TRIPLOBLASTIC ORGANISATION

COELENTERATES

An undifferentiated layer , mesoglea , is presentIn between the ectoderm and the endoderm , that Develop embryo has a 3rd Germinal layer , mesoderm

TRIPLOBLASTIC ANIMALS

Classification of Animals

Next

KINGDOM LEVELS SYMMETRY BODY CAVITY PHYLUM ORGANISATION

Cellular level

Animalia

Porifera

Tissue/OrganOrgan system

Radial

Bilateral

Coelenterata

Ctenophora

Acoelomates

Pseudocoe-Lomates

Coelomates

Platyhelminthes

Aschelminthes

AnnelidaArthropoda

MolluscaEchinodermataHemichordata

Chordata

PHYLUM- PORIFERASPONGES

EUSPONGIA

Commonly known as Sponges Primitive multicellularAnimals Digestion is intracellular. The body is supported bySkeleton – spicules or sporongin fibres .

WATER

OSTIA (MINUTE SPORE)

SPONOCOEL(CENTRAL CAVITY)

OSCULUM

ENTERS

This pathway helps inFood gathering ,

Respiratory exchange And removal of waste.

Asexually – fragmentation Sexually – formation of

gametes

TRANSPORT OF WATER

REPRODUCTIONSEXES ARE SEPARATE (HERMAPHRODITE)

COELENTERATAPENNATULA

ADAMSIA

Aquatic , marine and radiallySymmetrical , diploblastic•Used for anchorage , defenseAnd capture of prey.•Corals have a skeleton made calcium carbonate.Have central gastro vascularCavity - hypostom

EXHIBIT TWO BASIC FORMS CALLED POLYP AND MEDUSA

POLYP - THEY ARE SESSILE AND CYLINDRICAL – HYDRA

MEDUSA - UMBRELLA SHAPED AND FREE SWIMMING - AURELIA

POLUP PRODUCE MEDUSA ASEXUALLYMEDUSA PRODUCE POLYP SEXUALLY

REPRODUCTIONGORGONIA

PHYSALIA

CTENOPHORA•Commonly known as Sea walnuts / comb jellies• Radially symmetrical , diploblastic• Body Bears eight external – ciliated comb plates Helps in locomotion • Bioluminescene – the property of a living Organism to emit light .

PLEUROBRACHIA

PLATYHELMINTHESDorso-ventrally flattened body - FLATWORMS Endoparasites – in animals , humansBilaterally , triploblastic,coelomate.

PLANARIAFLATWORM

Hooks and suckers – parasitic formSome absorb nutrients from hostFlame cells – help in osmoregulation & excreation Planaria – high regeneration capacity

LIVER FLUKE

TAPE WORM

ASCHELMINTHES

oThe body is circular cross section - round wormsoFree living , parasitic or terrestialoOrgan system level .oBilaterally symmetrical , triploblasticAnd pseudocoelomate

ASCARIS

Alimentary canal is Complete with – Muscular pharynxAn excretory tube – Removes waste through – excretory spore

•Sexes are separate•Females are longer thanMaleFertilisation in internal

FILARIA WORM

HOOK WORM

ANNELIDA

Aquatic or terrestrial.Sometimes parasiticBilateral symmetry Triploblastic .Body surface – segmentsor metameres Locomotion – longitudnaland circular muscles

LEECH

EARTH WORM

NEREIS

Nereis – possess appendages , parapodia help in swimming Nephridia – help in osmoregulation and excreation Neural system – paired gangalia connected by lateral nerves to a double ventral nerve cord

ARTHROPODAo Largest phylum .o Bilaterally symmetrical and Triploblastic .o body covered – chitinous exoskeleton .o Have jointed appendages .o Respiratory organs –Trachea, Gills , Book gills , book lungs. o Sensory organs - Antennae ,Eyes , statocysts or balance are organs present .

oExcreation – Malpighian tubulesoThey are dioecious oFertilaisation – internalloEXAMPLES : Economically insects – Apis , bombyx ,Laccifer Vectors – Anopheles , culex , aedesGregarious pest – locusta Living fossil – limulus .

PHYLUM - MOLLUSCA•Second largest animal phylum .•Terrestrial and aquatic .•Bilaterally symmetrical .•Triploblastic and coelomateanimals .•Body – covered by Calcareous shell .•Dioecious and oviparous .

OYSTER PILA

SQUID

LET’S LEARN ON ..

ContainsRadula

RADICULE-FILE LIKE RASPING ORGAN FORFEEDING .

CHITON

ECHINODERMATAa. All are marineb. Have endoskeleton of calcareous ossicle c. Adult – radially symmetricald. Larva - Bilaterally symmetricale. Triploblastic and Coelomate

OPHIURA ASTERIASSEA LILY

WATER VASCULAR SYSTEM

Helps in locomotion,Transport of food andRespiration.Excretory systemAbsent. Reproduction is sexual.Sexes are separate .

SEA CUCUMBER

SEA URCHIN

PHYLUM - HEMICHORDATA i. Worm like marine animals

ii. Organ system leveliii. Bilaterally symmetricaliv. Triploblasticv. Coelomate

CIRCULATORY – OPEN SYSTEMEXCREATORY - PROBOSCISRESPIRATION - GILLS

Saccoglossus

BalanoglossusExample Proboscis

Collar

Trunk

PHYLUM CHORDATA

HOW CAN WE CHARACTERISE CHORDATAS….?

Presence of a Notochord A Dorsal Hollow Nerve Chord is

Present Chordates Have Paired

Pharyngeal Gill Slits

Chordates stand varied due to many reasons.

bilaterally symmetrical and triploblastic.

They are the only Phylum which are coelomates with organ-system level of organisation.

They possess a post anal tail and a closed circulatory system.

1

Subphyla Urochordata

2

Subphyla Cephalochordata

3

Subphyla Vertebrata

PHYLUM CHORDATA

SUBPHYLA UROCHORDATA AND CEPHALOCHORDATA ARE TOGETHER REFERRED TO AS PROTOCHORDATES.

THEY ARE EXCLUSIVELY MARINE.• UROCHORDATA NOTOCHORD IS PRESENT ONLY IN LARVAL TAIL. EG: ASCIDIA, SALPA,DOLIOLUM• CEPHALOCHORDATA NOTOCHORD EXTENDS FROM HEAD TO TAIL REGION AND

PERSISTENT HROUGHOUT THEIR LIFE.

EG:BRANCHIOSTOMA (AMPHIOXUS / LANCELET)

UROCHORDATA &CEPHALOCHORDATA

Characteristics Besides other chordates, vertebrates have: They possess notochord during embryonic period. It is replaced by a cartilaginous/bony vertebral column in adults. A ventral muscular heart with 2,3 or 4 chambers. Kidneys for excretion and osmoregulation. Paired appendages which may be fins or limbs.

ALL VERTEBRATES ARE CHORDATES BUT ALL CHORDATES ARE NOT VERTEBRATES.

VERTEBRATA` Vertebrates are divided into 7 classes :1. CLASS CYCLOSTOMATA2. CLASS CHONDRICHYTES3. CLASS OSTEICHTHYES4. CLASS AMPHIBIA5. CLASS REPTILIA6. CLASS AVES 7. CLASS MAMMALIA

Cyclostomes are ectoparasites on some fishes. They have an elongated body bearing 6-15 pairs of gill

slits for respiration. Their body does not possess any scales or paired fins. Their cranium & vertebral column are cartilaginous. They have closed circulation. They are marine but migrate for spawning in fresh

water. Their life span ends within a few days after spawning.

But their larvae return to the ocean.

CYCLOSTOMATA

They are marine animals with streamlined body and have cartilaginous endoskeleton.

Mouth is located ventrally. Notochord is persistent throughout their life span. Gill slits are separate without operculum (gill cover). Skin is tough, containing minute placoid scales. Teeth are modified placoid scales which are backwardly

directed. Their jaws are very powerful. Air- bladder is absent, so they have to swim constantly to avoid

sinking.

CHONDRICHTHYES

Heart is two-chambered. have electric organs and some possess poison

sting. cold-blooded animals. have different sexes, male and female. Males Pelvic fin have claspers. They have internal fertilization and many of

them are viviparous. Eg: Dog fish, Saw fish, Great White Shark, Sting

Ray.

• They are both marine and fresh water with bony endoskeleton.• Their body is streamlined.

• Mouth is mostly terminal.• They have four pairs of gills, covered by an operculum on each side.• Skin is covered with cycloid (ctenoid) scales.

• Air bladder is present which regulates up thrust.• Heart is two- chambered.

• They too have 2 different genders.• They possess external fertilization. They are mostly oviparous and development is direct. Eg: Exocoetus , Hippocampus, Labeo, Claris

OSTEICHTHYES

live both in water and land. Most of them have two pairs of limbs. Body is divided into head & trunk. Some possess tails. Skin - moist without scales.

Eyes - eyelids. Ear - represented by a tympanum. Respire through - lungs, gills & skin. Alimentary canal, urinary & reproductive tracts open into a

common chamber called clocoa.

AMPHIBIA

They have a three-chambered heart. They are cold-blooded animals. They have different genders

Fertilization is direct .Examples : toad , frog , Salamander , limblessAmphibia .

o Their possess the creeping or crawling mode of locomotion.o They are mostly terrestial.o Their body is covered by dry and cornified skin, epidermal

scales(scutes).Their ears are represented by tympanum.o Limbs are of two pairs, if present.o They have a three-chambered heart,excluding crocodiles

which have a four-chambered one.o Reptiles are cold-blooded animals.o Snakes & lizards shed their scales as skin cast.o They have different genders . Fertilisation is internal.o They are oviparous and development is direct. Eg: Turtle, Tree lizard, Crocodile, Cobra

REPTILIA

The presence of feathers, makes them to fly, a beak and wings(modified forelimbs).

Their hind limbs are modified for walking, swimming, or clasping branches.

Skin is dry without glands except the oil gland in the base of the tail.

Endoskeleton is fully bony and long bones are hollow.

AVES

The digestive tract has additional chambers, crop & gizzard.Heart is four-chambered and they are warm-blooded animals. Respiration is done by lungs.They have different genders. Fertilisation is internal. They are oviparous & development is direct.Eg: Crow, Pigeon, Parrot, Ostrich, Vulture

found in a variety of habitats. Some are adapted to fly or live in

water. they possess milk producing glands by

which their young ones are nourished. They have two pairs of limbs, for

walking, running, climbing, etc.

MAMMALIA

Their skin possess hair. External ears are present. Heart is four chambered. Respiration is

done by lungs. They are warm-blooded. They have different genders,

fertilization is internal. They are viviparous and development

is direct.Eg: Dog, Platypus, Tiger, Rat, Dolphin

END OF THE CHAPTER