Question
Biology Question on Microbes in human welfare
The biofertilizers are
A
Anabaena and Azolla
B
cow dung, manure and faryard waste
C
quick growing crop ploughed under soil
D
none of these.
Answer
Anabaena and Azolla
Explanation
Solution
Biofertilizers are organisms which bring about nutrient enrichment of the soil. Azotobacter is a free living, aerobic, nitrogen fixing bacteria. Anabena is a nitrogen fixing cyanobacteria that occurs in both free living and symbiote associations with Azolla, Cycas roots etc. Rhizobium lives symbiotically in root nodules of legumes and non-legumes. Vesicular-arbuscular mycorrhiza (VAM) is an example of endomycorrhiza in which fungal hyphae penetrate the cortical cells of grasses to form vesicles.