Consider the following bacteria:
Which among the above fix nitrogen without being in symbiotic relation with other biota?
Two kinds of nitrogen-fixing bacteria are recognized:
- Free-living (non-symbiotic) bacteria, including the cyanobacteria (or blue-green algae) Anabaena and Nostoc and genera such as Azotobacter, Beijerinckia, and Clostridium;
- Mutualistic (symbiotic) bacteria such as Rhizobium, associated with leguminous plants (e.g., various members of the pea family), and certain Azospirillum species, associated with cereal grasses.
This question is a part of GKToday's Integrated IAS General Studies Module