What type of body organization is found in animals of the phylum $Porifera$?

Cellular level of organization is found in .........

In $Sycon$,which pathway is correct for water circulation into the body?

Assertion $(A)$: Animals are multicellular organisms composed of eukaryotic cells.
Reason $(R)$: Sponges do not perform photosynthesis and obtain nutrition by absorption.

$A$ skeleton made of spongin fibres occurs in

Physiological division of labour is almost not shown by the animals belonging to