Q.Draw Gemmule in sponges and label the parts. [figure: labelled diagram of a gemmule in sponges, to be drawn by the candidate — not printed in the question paper]

In budding, the parent produces one or more small outgrowths (buds), each of which grows into a young individual and typically detaches to lead an independent life - in sponges such as Leucosolenia, buds constrict at their base and separate, each developing into a complete new sponge. When buds form on the parent's outer body surface, the process is exogenous budding, best illustrated by Hydra: when food is plentiful, ectoderm cells proliferate into a small elevation, both ectoderm and endoderm are pushed outward to form a bud whose lumen stays continuous with the parent's gastro-vascular cavity, and the bud enlarges, grows a mouth and tentacles, then constricts at its base and detaches to live independently. When buds instead form inside the parent's body, with many remaining enclosed within it, the process is endogenous budding, seen in Noctiluca, which can form hundreds of internal buds within its own cytoplasm …