Question

Gemmule formation in sponges are useful in
A. Asexual reproduction
B. Sexual reproduction
C. Parthenogenesis
D. Parthenocarpy

Answer 1

Hint:-Gemmules are tiny cells close to buds that are produced by sponges to survive unfavourable environmental circumstances. A sponge with fresh water reproduces both sexually and asexually.

Complete Answer:-A Gemmule is an asexually formed mass of cells capable of evolving into a new organism or into an adult freshwater sponge. Asexual reproduction is carried out mostly by budding and by gemmulation as well. Gemmules are the inner buds that are produced by freshwater sponges. These gemmules are rough and covered with a cluster of embryonic cells that are dormant.

The multicellular, aquatic living creatures of Kingdom Phylum-Porifera are freshwater sponges. Sponges, Ficulina ficus, sea sponges and many more compose the species of this kingdom. Both animals belong to the same kingdom and are characterised by the same characteristics. Gemmules, the inner buds, are immune to dehydration, freezing and can survive without an oxygen supply.

With the endospore covered by a coating of spicules, the outer layer of the gemmule is sealed and secured, which allows the gemmule to mature into an adult freshwater sponge from all other unfavourable environmental factors. Gemmules, along with a central mass of ameboid cells and a dense peripheral layer with a thin siliceous spicule, are typically located in a circular or ball-like shape.

Gemmule is produced by a few genus of freshwater sponges, such as Spongilla, and some marine species, including ficulina ficus, sea sponges, and other poriferous species, which produce gemmules for survival under adverse circumstances and for the germination and development of new sponges.

So from these discussions we can conclude that Gemmule formation in sponges are useful in asexual reproduction.

Therefore the correct answer is option (A).

Note:- Gemmules are resistant to anoxia (lack of oxygen) and desiccation (drying out), freezing, and can lay about for long periods of time. Gemmules are analogous to the endospore of a bacterium and are composed of amebocytes enclosed by a spicule coating and can withstand environments that would destroy adult sponges. The gemmule restarts to expand as the world becomes less aggressive.