BIOLOGY [2 Mark Question Answer]

Gobar gas or biogas is obtained from cowdung, garbage etc. when it is placed in biogas plants where anaerobic bacteria produce methane etc. The waste slurry is used as manure.

In sewage treatment plants, microbes are utilized as scavengers to remove organic matter from sewage. Bacteria, algae and fungi play important roles in sewage treatment.

Certain microorganisms control or prevent spread of other organisms. They are utilized as bio-control agents. Example - Certain fungi which kill agricultural weeds are utilized as bio-weedicides.

Biofertilisers are organisms that enrich the nutrient quality of the soil. The main sources of biofertilisers are bacteria, fungi and cyanobacteria. Certain bacteria and blue-green algae fix atmospheric nitrogen and make it available to plants.

Some food items prepared using microbes are bread, idli and dosa (South India), soya sauce, koji (Japan), temph (Indonesia), curd, cheese, butter and gari (West Africa).

Biotechnology is the study and use of techniques using living organisms or their products for the benefit of human race. It is the controlled use of biological agents such as microorganisms or cellular components for beneficial uses.