The document discusses three phyla: Porifera, Coelenterata, and Ctenophora. It describes their key characteristics including habitat, body organization, symmetry, digestive and nervous systems, and modes of reproduction. Sponges have a canal system for water transport and intracellular digestion. Coelenterates have a gastrovascular cavity and tentacles surrounding the mouth. Ctenophoras are biradially symmetrical and lack organ systems, with digestion and gas exchange occurring directly through their surfaces.

2. Chapter 4
Animal Kingdom
Phylum Porifera, Phylum Coelenterata and Phylum Ctenophora
Lecture no.2

3. Phylum Porifera
 Porous-pore; ferre-to bear
 They are the most primitive multicellular
animals.
 They are also called as pore bearing
animals
 Members of this phylum are commonly
known as sponges.
 Habitat-Marine and fresh water habitat,
found in ponds and lakes e.g.,Spongilla
 Shape-Vase like cylindrical shape and
majority have irregular shape
 Size-Ranges from 1cm to 1 m in length.

5. Phylum Porifera
 Symmetry-Cylindrical form(Sycon)shows
radial symmetry, while sponges shows no
symmetry
 Body organization-Sponges shows cellular
level of organization.
 Germ Layers-These are diploblastic;
having ectoderm and endoderm
 Skeleton-It is internal and includes
inorganic spicules and organic sponging
fibers.

6. Canal system-
Phylum Porifera
 Sponges have a water transport or canal system. Water enters
through minute pores (ostia) in the body wall into a central cavity,
spongocoel, from where it goes out through the osculum.
 This pathway of water transport is helpful in food gathering,
respiratory exchange and removal of waste.
 Choanocytes or collar cells line the spongocoel and the canals.

8.  Digestion-It is intracellular in nature (inside collar
cells)
 Circulation-The amoeboid cells transport food from
ingesting cells to other cells
 Respiration-It occurs through the body surface by
diffusion
 Excretion-It occurs through the body surface by
diffusion in the form of ammonia.
 Sensory system-Sponges lack sensory and nerve
cells, so they are poor in response to stimuli.

9.  Sponges reproduce both asexually and
sexually .
 Asexual reproduction occurs by budding
or fragmentation
 Sexual reproduction involves fusion of
ova and spermatozoa
 Fertilization is internal
Reproduction

10. Phylum Coelenterata
 They are also known as Cnidaria
 Habitat-They are marine organism but few of them
are fresh water
 Body organization-They have tissue level
organization.
 Germ layers-They are diploblastic
 They have a central gastro-vascular cavity with a
single opening, mouth on hypostome
 Tentacles-The mouth is surrounded by many thin,
long, slender hollow structure called tentacles.

12.  Skeleton-A calcareous exoskeleton as well as endoskeleton is
present.
 The coelenterates with exoskeleton of calcium carbonate are called
corals
 Digestion- In gastro vascular cavity both intracellular and
extracellular digestion occur.
 Respiration and Excretion- Exchange of gases and excretion occur
directly as all the cells are in direct contact with water.
 Nervous system-It is in the form of a nerve net, neurons are loosely
arranged in the body wall
 Polymorphism-Cnidarians are mainly of two types of individuals:
polyp(cup-shaped) and medusa(umbrella-shaped)

13. Reproduction
 They reproduce both by asexual and sexual methods.
 Fertilization-It may be external or internal
 Examples: Physalia (Portuguese man-of-war), Adamsia
(Sea anemone), Pennatula (Sea-pen), Gorgonia (Sea-fan)
and Meandrina (Brain coral).

14. Phylum – Ctenophora
 Habitat-These are marine organism. They are pelagic or free
living
 Body organization-They are diploblastic, acoelomate with tissue
level of organization. Body is soft, delicate, transparent and
gelatinous.
 Body symmetry- They are biradially symmetrical .The
arrangement of comb plates gives the appearance of radial
symmetry.
 Digestive System-Digestion is both extracellular and intracellular.
 Skeletal, circulatory, respiratory and excretory system are absent

15. Respiration and Excretion
 These process occur through general body surface.
 Nervous System-It consists of nerve cells with an
aboral sense organ called statocyst for balance.
 Reproduction and development :They are monoecious.
Gonads are endodermal .Fertilization is external .
e.g. Ctenophora, pleurobranchia
Locomotion
The body bears eight external rows of ciliated comb
plates, which help in locomotion

17. 1. The body cavity formed by the splitting of the
mesoderm is called
(a) pseudo coelom
(b) coelom
(c) haemocoel
(d) blastocoe
(b) coelom
MCQ

18. 2. Which of the following level of organization is
found in coelenterates?
(a) cellular
(b) tissue
(c) organ
(d) organ system
(b) tissue

19. 3. The tapeworm takes its food by
(a) suckers
(b) mouth
(c) scolex
(d) skin
(d) skin

20. 4. Chordates may not have a
(a) vertebral column
(b) dorsal nerve cord
(c) gill slits
(d) notochord
(a) vertebral column

21. 5.Which of the following is found in sponges only?
(a) mesoglea
(b) nerve cells
(c) one exit
(d) numerous inlets
(d) numerous inlets

22. 6.Which of the following level of organization is found in coelenterates?
(a) cellular
(b) tissue
(c) organ
(d) organ system
(b) tissue

23. 7.The cavity present in Hydra is called
(a) haemocoel
(b) coelom
(c) blastocoel
(d) coelenteron
(d) coelenteron

24. 8.The pathway of entering and coming out of water in sponges is________
(a) Water vascular system
(b) Canal system
(c) Feeding current
(d) Circulating current
(b) Canal system

25. 9.Ctenophores commonly known as ___
A. Sea Walnuts
B. Flatworm
C. Ascaris
D. Tapeworm
A. Sea Walnuts

26. 10.The organ level organization is first seen in:
a. Concentrates.
b. Platyhelminthes.
c. Nematahelminthes.
d. Arthropods
(b) Platyhelminthes

27. 11. Bioluminescence is prominent in the phylum:
a. Porifera.
b. Ctenophora.
c. Platyhelminthes.
d. Nemtahelminthes.
b. Ctenophora