Question

Difference between porriferan animals and coelenterates..

Answer 1

Poriferans show cellular grade of organisation whereas coelenterates show tissue grade of organisation.

Poriferans show numerous pores called ostia which are absent in coelenterates.

Mouth is absent in poriferans but present in coelenterates.

Coelenteron is present in coelenterates but absent in poriferans.

Skeleton shows spicules in porifera which are not seen in coelenterates. In several coelenterates a hard exoskeleton is present

Coelenterates possess cnidoblasts bearing stinging cell organelles called neamatocysts. These are absent in poriferans.

Polymorphism is seen in coelenterates but not in poriferans.

Answer 2

porifera -

the word means organisms with holes

these are non motile animals attached to some solid support.

they have holes or pores all over the body

they have canal system that helps in circulating water throughout the body to bring in food and oxygen

their body design has minimal differentiation

they are marine habitat, commonly called sponges .

examples sycon , spongilla

coelenterata -

they live in water

they have more body differentialisation

they have cavity in the body

they are made up of two layers

some of the species live in colonies (corals), while other have a solitary like span (hydra)

examples jellyfish , sea anemone