Question

Asexual reproduction through formation of gemmule occurs in
A. Ascidia
B. Hydra
C. Planaria
D. Spongilla

Answer 1

Hint: It belongs to the phylum Porifera and it can reproduce both sexually and asexually. This genus is found in freshwater.

Complete Answer:
In asexual reproduction only one parent involves. Depending upon the conditions in which organism is reproducing, asexual reproduction have various modes. Asexual reproduction can be classified as multiple fission, plasmotomy, budding, sporulation, binary fission, fragmentation, and vegetative propagation.

A) Ascidia and Hydra reproduce asexually by budding. The buds develop from the wall of the body, develop into tiny adults, and split apart when mature.
B) Planaria reproduces asexually by binary fission. They simply tear themselves into two pieces which then go on to form two mew worms within a week.
C) Asexual reproduction occurs in spongilla by the development of gemmules. Spongilla belongs to the Porifera phylum. They reproduce in a sexual and asexual manner.
- The asexual mode is budding. In this process, a new individual is created from a bud or outgrowth due to cell division at one specific location of the parent body.
- In sponges, a portion of the parent body produces internal buds termed as gemmules, which detach from the mother's body and create a new individual. The gemmules are formed in the mesoglea layer of the wall of the body.

Hence the correct answer is option ‘D’.

Note: Gemmules are asexual reproductive bodies produced by endogenous budding in some marine sponges and freshwater sponges. The regeneration of sponges by gemmules is attributed to archaeocytes, hence these archaeocytes are the reproductive cells found in gemmules.