Name two free-living `N_2`-fixing microbes.

Name two symbiotic N_2 -fixing microbes.

An example of free living nitrogen fixing aerobic bacteria is

Name the free living flatworms.

Name two free living micro-organims which can fix nitrogen.Also write the name of the water fen and a gymnosperm with whom some cyanobacteria have symbiotic association.

Which of the following is a free-living nitrogen-fixing bacteria present in the soil?

Fill in the blanks _______ and _______ are free living nitrogen fixing bacteria.

Name a free living and a symbiotic bacterium that serves as biofertilizer. Why are they called so?

Name two nitrogen fixing algae.

Name two n-impurities?