Types of Reproduction - Asexual Reproduction

Asexual Reproduction in animals:

• The formation of progeny is by a single parent only and does not involve both the sexes, so it is called asexual reproduction. 
• The progeny or daughter cells are genetically identical to the single parent and are also called clones. 

Modes of asexual reproduction:

1. Gemmule Formation

• A gemmule is an internal bud found in sponges, consisting of asexually produced dormant cells called archaeocytes.
• These cells can develop into new organisms when coated by a thick layer of amoebocyte secretion.
• When favourable conditions return, the gemmule hatches and develops into a new organism, like sponges.

Gemmule 

2. Budding

• It is a simple method, occuring in favorable conditions. In Hydra, a small outgrowth (bud) is produced towards the basal end of the body.
• It develops as a bud which grows and forms tentacles and develops (get transformed) into a new individual. This process is called budding.

Budding in Hydra

3. Regeneration

• By this process, the organism can repair, regrow or restore its lost or damaged part. Though it involves asexual processes, it differs distinctly from reproduction, e.g., a damaged hydra can regenerate its lost part.
• Similarly, Planaria if wounded, its cells become active and regenerate lost part or organ back to its original state.

Regeneration in planaria