Calcareous spicules are formed by (a) Scleroblasts
(by Calcoblasts
(c) Silicoblasts
(d) Spongioblasts
The cavity present in sponge is
(a) Gastrovascular cavity (b) Spongocoel
(c) Paragastric cavity (d) Both b and c
In sponges, nitrogenous waste is eliminated in the
( a) Ammonia
(b) Urea