Question

Describe the various types of Asexual reproduction so as explain in detail spore - formation

Answer 1

Various types of asexual reproduction are :

1) Fission - Division of the parent body into two or more daughter individuals identical to the parent. It is of two types:

(i) Binary fission: In this process, the parent organism divides into two halves, each half forms an independent daughter organism. E.g., bacteria, protozoans.

(ii) Multiple fission: Here the parent body divides into many daughter organisms. E.g., Amoeba, Plasmodium.

2) Budding- Formation of a daughter individual from a small projection, the bud, arising on the parent body is called budding. It occurs in Hydra, Scypha.

3) Strobilisation- In this process, a series of a ring-like transverse constriction are developed, organism looks like a pile of minute saucers. The segmented body is called a strobila. E.g., Aurelia.

4) Fragmentation- Here, the parent body breaks into two or more fragments. Each fragment develops into an organism. E.g., sponges, sea anemones, echinoderms.

5) Gemmae- These are specialised structures which are green, multicellular, asexual buds, which develop in a small receptacles called gemma cups located on the thalli. Its is found in liverworts (e.g., Marchantia).

6) Regeneration- Formation of the whole body of an organism from a small fragment or the replacement of the lost part. E.g., Planaria.

7) Spore formation- Spores are propagules which germinate to produce new individuals. There are several kinds of spores. These are zoospores, sporangiospores, chlamydospores, oidia, conidia.

8) Vegetative reproduction- It is the formation of new plants from vegetative units such as buds, tubers, rhizomes, etc. These vegetative units are called as vegetative propagules.