Question

5. Nitrogen fixation is done by bacteria.​

Answer 1

Explanation:

Nitrogen-fixing bacteria, microorganisms capable of transforming atmospheric nitrogen into fixed nitrogen (inorganic compounds usable by plants). More than 90 percent of all nitrogen fixation is effected by these organisms, which thus play an importa

Answer 2

Nitrogen fixation is done by bacteria

Explanation:

• Micro organisms are capable of fixing  atmospheric nitrogen , mostly 90% of nitrogen fixation is done  by these organisms.
• There are two kinds of nitrogen fixing bacteria - Free living  non symbiotic bacteria  which includes cyanobacteria ( anabena , nostoc ), Azotobacter, beijerinckia & clostridium.
• Thse second is symbiotic  ,  for example Rhizobium, it is associated with leguminous plants .
• Frankia is associated with certain dicot plants .
• Symbiotic bacteria fix nitrogen by formation of root nodules , and have leghaemoglobin which acts as an oxygen scavenger .