Question

Vegetative reproduction in algae.

Answer 1

Vegetative reproduction takes place by different methods. They are:

1. Cell division: In certain unicellular members reproduction takes place by cell division. This type of reproduction is found in diatoms, euglena etc. It is sometimes known as binary fission.
2. Fragmentation: In this type of reproduction the parent filaments break into fragments. Then each fragment develops into each organism; it is found in filamentous as well as colonial forms. Fragmentation takes place in Ulothrix, Spirogyra, and Nostoc etc.
3. Hormogonia: In some blue green algae the fragments undergoes a gliding movement which are called hormogonia. Each hormogonium develops into new organisms. Oscillatoria, Nostoc etc. undergoes hormogonia formation.
4. Autocolony: Autocolony formation occurs in coennobial algae. Each cell within the parent colony can give rise to new miniature colony.
5. Akinetes: It is the type of reproduction very common in the blue green as well as green algae. These akinetes are a type vegetative cell which is thick walled and will overcome the unfavourable conditions. These akinetes then develops into new plants as in Oedogonium, Ulothrix.
6. Bulbils: A bud like structure develops usually on the rhizoids; these are known as bulbils. Each bulbil develops into new ones.