Question

Cell aggregate plan is found in
A) Cnidarians
B) Sponges
C) Roundworms
D) Flatworms

Answer 1

The cell aggregate plan is a type of body plan in which the body has cluster or aggregation of cells which are not organized into tissues or organs. In the blind sac plan, the body has a single cavity which functions as digestive tract and coelom both.

Complete answer:
->Sponges are the members of phylum porifera.
->Sponges are multicellular organisms consisting of bodies full of pores and channels.
->Sponges do not have nervous, digestive and circulatory systems.
->The bodies of sponges are full of pores and channels that allow water to circulate through them.
->Presence of unspecialized cells that can transform into other types in sponges.
->The cell aggregate plan is found in sponges.
->Sponges have cellular levels of body organisation.
->Cnidarians have tissue level of body organisation.
->Roundworms constitute the phylum Nematoda.
->Roundworms have organ level organisation .
->Flatworms have organ level of organisation.
->Blind sac body plan is found in cnidaria, flatworms.

So the correct answer is option ‘B’ sponges.

Note: In the cell aggregate body plan, the cells do not form tissues or organs. Many sponges have internal skeletons of spongin or spicules of calcium carbonate or silicon dioxide. Cnidarians have simple nervous systems and cell layers are bound by internal connections. In the tube within a tube body plan there are two openings one for food to enter the body and other for wastes to leave the body example- roundworms.