Question

Write the main features of phylum Porifera, coelenterates, and phylum Platyhelminthes.​

Answer 1

Explanation:

$\Large\underline{\underline{\sf{\purple{Required\ Answer:-}}}}$

~ Main features of the phylum Porifera ::

➴ They are primitive animals.

➴ They are generally multicellular organisms with specialised cells but these cells do not group together to form tissues.

➴ Most of them are marine, found in the seas. Some of them are also found in ponds and rivers.

➴ They posses pores all over the body.

➴ Reproduction can be by both sexual and asexual methods.

➴ Sensory system is absent.

➴ Mouth and anus are absent.

➴ A distinct canal system with inlets and outlets for water circulation inside the body is present. They obtain food and oxygen by means of water. The collar cells filter out food particles from the water current flowing through the canal system.

Examples are : Sycon, Spongilla and Euplectella.

~ Main features of the coelenternates ::

➥ Diplobastic animals with tissue level organisation in the body.

➥ The body is radially symmetrical.

➥ The body bears tentacles supplied with special stinging cells called cnidoblasts.

➥ There is a cavity in the body.

➥ Body is made of two layers of cells.

➥ Simple gonads without gonoducts are present.

➥ Reproduction is usually asexual (budding) in polyp form and sexual in medusae form.

➥ They show polymorphism.

Examples are : Hydra, Obelia and Jelly fish.

~ Main features of the phylum Platyhelminthes ::

➽ They show bilateral body symmetry.

➽ Their body is dorsoventrally flattened like a ribbon. So they are also called flatworms.

➽ Most of them are parasitic, only a few are free living.

➽ They are mostly hermaphrodites.

➽ There are three embroyonic layers of cells in their body. So, they are tripoblastic.

➽ The body does not have any pore or cavity.

➽ They have power of regeneration.

Examples are : Fasciola (Liver fluke), and Taenia solium.

Answer 2

Answer:

The above answer is correct