Slide 1

ANIMAL KINGDOM NONCHORDATES

CLASS XI

DR. U.P.PANI

PGT (BIOLOGY)

JNV DURG

Arrangement of cells

Body Symmetry

Nature of Coelom

Patterns of Digestive

Circulatory System

Reproductive System

Basis of Classification

LEVELS OF ORGANISATION

Cellular level of Organisation

Loose cell aggregates, eg. Sponges

Tissue level of Organisation

Eg. Coelenterates

Organ level of Organisation

Eg. Platyhelminthes

Organ System level of Organisation

Eg. Annelids, Arthropods, Molluscs,

Echinoderms, Chordates

BODY SYMMETRY

Asymmetrical symmetry

(Body can not be divided into two equal halves)

e.g. Sponges

Radial symmetry

(Body divides the organism into two identical halves through any plane)

Coelenterates

Bilateral symmetry

(body can be divided into identical left and right halves in only one plane)

e.g . Human

EMBRYONIC LAYERS

Diploblastic animals

Two embryonic layers

Ectoderm and endoderm

e.g. Coelenterates

Triploblastic animals

Three embryonic layers

Ectoderm, mesoderm and endoderm

e.g. Platyhelminthes to Chordates

Coelom - The space between the body wall and the gut wall is called coelom.

COELOM

1. Coelomates

True coelom present

e.g. Annelids, to chordates

2. Pseudo coelomates

Mesoderm present as scattered pouches between ectoderm and endoderm.

e.g. Aschelminthes

3. Acoelomates

Body cavity absent

e.g. Platyhelminthes

Notochord is a rigid rod-like structure formed on the dorsal side during embryonic development in some animals.

NOTOCHORD

Animals

Chordates

(Notochord present)

Fishes to Mammals

Non-chordates

(Notochord absent)

Porifera to Echinoderms

NONCHORDATES

1.Porifera

2.Coelenterata

9.Echinodermata

4.Platyhelminthes

5.Aschelminthes

6.Annelida

7.Mollusca

8.Arthropoda

3.Ctenophora

Important Characteristics :-

1. Commonly called sponges

2. Multicellular cell aggregate animals.

3. Diploblastic and assymetric body.

4. They have perforated body by numerous pores and have a water transport or canal system.

5. Water enters through minute pores (ostia) in the body wall into a central cavity, spongocoel, from where it goes out through the osculum.

6. Digestion is intracellular.

7. Sexes are not separate (hermaphrodite)

1. PHYLUM PORIFERA

8. Skeleton consists of spicules or spongin fibres.

9. Asexual reproduction by fragmentation

10. Sexual reproduction by formation of gametes

11. Fertilisation is internal and development is indirect having a larval stage

Eg. Sycon, Spongilla, Leucosolenia

Important Characteristics :-

Aquatic, mostly marine, sessile or free-swimming.

Diploblastic animal, radially symmetrical.

Exhibit tissue level of organisation

Cnidaria is derived from the cnidoblasts or cnidocytes which contain nematocytes on the tentacles and the body.

Hydra lives in solitary while corals live in colonies.

They have a central gastro-vascular cavity with a single opening, hypostome.

Digestion is extracellular and intracellular.

2. PHYLUM CNIDARIA (COELENTERATE)

Cnidarians exhibit two basic body forms called polyp and medusa.

Polyp is a sessile and cylindrical form like Hydra, Adamsia, etc.

Medusa is umbrella-shaped and free-swimming like Aurelia or jelly fish.

Eg. Hydra, Obelia, Aurelia, Physalia etc.

Aurelia (Medusa)

Adamsia (Polyp)

Commonly called sea walnuts or comb jellies.

Exclusively marine, radially symmetrical, diploblastic

Tissue level of organisation.

Eight external rows of ciliated comb plates help in locomotion.

Digestion is extracellular as well as intracellular.

Bioluminescence (emitting light) is well-marked.

Hermaphrodite and reproduction takes place by sexual means.

Fertilisation is external with indirect development.

e.g. Pleurobrachia and Ctenoplana.

3. Phylum Ctenophora

Pleurobrachia

Body dorsoventrally flattened.

Bilateral symmetry, triploblstic and acoelomate animals.

Organ level of organisation.

Mostly endoparasites found in animals and human beings.

Flame cells for osmoregulation and excretion.

Hermaphrodites, fertilisation internal and development is through larval stages.

Planaria possess high regeneration capacity.

e.g. Taenia solium, Fasciola, Planaria

4.PHYLUM PLATYHELMINTHES

Fasciola

Body is cylindrical, bilaterally symmetrical, triploblastic and pseudocoelomate animals.

May be freeliving, aquatic and terrestrial or parasitic in plants and animals.

Alimentary canal is complete with muscular pharynx.

Dioecious, females are longer than males.

Fertilisation internal, development may be direct or indirect.

e.g. Ascaris (Round worm), Ancylostoma

(hook worm), Wuchereria (Filarial worm)

5. ASCHELMINTHES

Ascaris

Body is soft, elongated, cylindrical and externally segmented.

Bilaterally symmetrical, triploblastic, and coelomate animals.

Aquatic (fresh water or marine) or terrestrial, free-living / parasitic.

Organ-system level of body organisation

Longitudinal and circular muscles help in locomotion.

Nereis possess parapodia helps in swimming.

Circulatory system is closed.

Nephridia is for osmoregulation and excretion.

Neural system consists of paired ganglia connected by lateral nerves to a double ventral nerve cord.

6. PHYLUM ANNELIDA

Nereis is dioecious, but earthworms and leeches are monoecious.

Reproduction is sexual.

e.g. Pheretima (Earthworm), Hirudinaria (Leech) and Nereis

Earthworm

Arthopoda, the largest phylum of Animalia kingdom.

Bilaterally symmetrical ,triploblastic, segmented and coelomate animals.

Organ-system level of organisation.

Have jointed appendages and body covered by chitinous exoskeleton.

Body consists of Head, thorax and abdomen.

Respiratory organs are gills, book gills, book lungs or tracheal system.

Circulatory system open type.

7. PHYLUM ARTHROPODA

Nervous system includes a brain and ganglia.

Sensory organs are antennae, compound and simple eyes.

Excretion by malpighian tubules.

Dioecious, oviparous, fertilisation internal, development may be direct or indirect.

e.g. Periplaneta (Cockroach), Limulus (King crab), Prawn, Insects, Scorpion

Prawn

Molluscs, the second largest phylum of Animalia.

Bilaterally symmetrical, triploblastic and coelomate.

Organ-system level of organisation.

Unsegmented body covered by a calcareous shell.

Body has 3 parts: head, muscular foot and visceral hump.

8. PHYLUM MOLLUSCA

Mantle secretes the hard prtesctiveshell.

Radula - toothed structure in mouth used for feeding.

Open circulatory system

Dioecious, oviparous and development is indirect.

Examples: Pila, Pinctada, Sepia, Octopus etc.

Unio

Sepia

Exclusively marine forms.

Adults are radially symmetrical while larvae are bilaterally symmetrical.

Triploblastic and coelomate animals.

Organ-system level of organisation.

They have endoskeleton of calcareous ossicles.

Digestive system is complete.

Water vascular system help in locomotion, capture and transport of food and respiration.

Excretory organ absent.

Show very high power of regeneration.

Sexes are separate, reproduction is sexual.

9. PHYLUM ECHINODERMATA

Fertilisation external, development is indirect.

Examples: Asterias (Star fish), Echinus (Sea urchin), Antedon (Sea lily), Cucumaria (Sea cucumber) and Ophiura (Brittle star).

Asterias

(Star fish)

Cucumaria

(Sea cucumber)