Q93
General ScienceBiology
The nitrogen fixation in a paddy field is brought about by
- a.Bacteria
- b.Fern
- c.Cyano bacteria
- d.Algae
Answer: (C) Cyano bacteria
In flooded paddy fields, free-living and symbiotic cyanobacteria such as Anabaena, Nostoc and Tolypothrix fix atmospheric nitrogen and serve as biofertiliser. The fern Azolla helps only because of the cyanobacterium Anabaena living in it, so (B) is not the fixer itself.