Question

Gemmules are formed by
A) Spermatocytes
B) Oocytes
C) Amoebocytes
D) Archaeocytes

Answer 1

An asexually produced mass of cells, that can transform either into a new organism or into an adult freshwater sponge is called a Gemmule. They are small bud-like cells, which are produced by sponges to tolerate unfavourable conditions in the environment. A freshwater sponge reproduces both sexually as well as asexually.

Complete answer:
Freshwater sponges or Spongilla produce special bodies called gemmules. During unfavourable conditions, gemmule germinates and produce new sponges. For gemmule formation, archaeocytes which are totipotent cells, are laden with the food material in the form of glycoprotein or lipoprotein gets and is combined into a mass. Amoebocyte moves and surrounds the central mass of archaeocytes and produces thick solid chitin around archaeocytes and thereby forms a layer around them.

Spermatocytes are the male gametocytes in animals that are derived from germ cells that are immature
called spermatogonia. They are found in the testis, in a structure called the seminiferous tubules. There are two types of spermatocytes which are known as primary and secondary spermatocytes.

An oocyte is a female gametocyte or a germ cell that is involved in reproduction. An oocyte is produced in the ovary during the process of female gametogenesis.

Amoebocytes are amoeba-like cells found in sponges that are able to divide, and form differentiates cells in nature.

Thus, the correct answer is option ‘D’ i.e, Archaeocytes.

Note: Gemmule is produced by few genera of freshwater sponges and some marine species like figuline ficus, sea sponges, and others, that produces gemmules to live in the unfavourable conditions, to germinate and produce new sponges. During gemmule formation, the archaeocytes that are loaded with food material either in the form of glycoprotein or lipoprotein get combined into a mass.