Question

Choose the correct statements with reference to demospongiae.
(a) They are exclusively marine forms.
(b) They are colonial forms.
(c) Skeleton consists of siliceous spicules and spongin fibres.
(d) They are solitary and simple forms.

• A. (b) and (d)
• B. (b) and (c)
• C. (a) and (d)
• D. (a) and (c)

Answer 1

Answer: (B)

(b) and (c)

(a) Class Demospongiae has all marine forms except freshwater family Spongillidae.

(b) They are not colonial. Body shape is vase like or cup like or cushion like.

(c) Skeleton consists of siliceous spicules or spongin fibres or both.

(d) The body organisation is of leuconoid type and thus, is very complex.

Hence, statements b and c are correct.

So, the correct answer is '(b) and (c)'.