NEET BIOLOGY

Detailed explanation-1: -The common asexual reproductive structure in sponges is gemmules. Gemmules: They are internal buds and capable of producing a whole new individual. Gemmules survive during unfavourable conditions and germinate during favourable conditions.

Detailed explanation-2: -Asexual reproduction is mainly carried out by budding and also by gemmulation. The internal buds, which are formed by the freshwater sponges, are called gemmules. These gemmules are tough and coated with a dormant cluster of embryonic cells.

Detailed explanation-3: -Gemmules are seed-like capsules formed by sponges for overwintering, containing cells from which a new sponge can grow. Gemmules have the characteristics that identify sponges to the species level: With a tube (surrounding the foraminal opening (f) to the exterior of the gemmule) extending from the gemmule surface.

Detailed explanation-4: -Gemmule Reproduction among Sponges The exterior gemmule layer is surrounded by endospore, further surrounded by spicule, which also protects. As a result, gemmules can grow into freshwater sponges.

Detailed explanation-5: -Sponges can be found in fresh or saltwater habitats. As part of their life cycle, many sponges produce gemmules as a means of surviving environmental challenge. In most sponges, the gemmules contain cells that are initially in a state of metabolic arrest that is controlled by endogenous factors.