ii) Identify the phylum of the given animal and write any two characteristic of this
phylum.
- Match the pairs.
Answers
Answer:
. Phylum Porifera
Primitive multicellular organisms with cellular level of organisation
They are generally marine and asymmetrical
Digestion is intracellular.
The body is supported by a skeleton made up of spicules or spongin fibres.
Sexes are not separate, thus they are called hermaphrodite (egg and sperms are in the same individual).
Sponges reproduce asexually by fragmentation and sexually by formation of gametes.
Fertilisation is internal
Development is indirect having a larval stage which is morphologically distinct from the adult.
Examples: Sycon, Spongilla, etc.
2. Phylum - Colenterata (Cnidaria)
They are aquatic, mostly marine, sessile or free-swimming.
Radially symmetrical animals
Exhibit a tissue level of organisation
They are diploblastic.
Digestion is intracellular and extracellular.
They have stinging capsules present on the tentacles and the body. These Cnidoblasts are used for anchorage, defense and for capture of prey.
They exhibit two basic body forms called polyp (sessile and cylindrical) and medusa (umbrella-shaped and free-swimming.
Examples: Physalia, Adamsia, etc.
3. Phylum - Ctenophora
Commonly called sea walnuts or comb jellies
Exclusively marine
Radially symmetrical
Diploblastic organisms with tissue level of organisation
Has eight external rows of ciliated comb plates for locomotion
Digestion is both intracellular and extracellular.
Exhibits the property of bioluminescence.
Sexes are not separate.
Reproduction takes place only by sexual means.
Fertilisation is external with indirect development.
Examples: Pleurobrachia and Ctenoplana
4. Phylum – Platyhelminthes