Leghaemoglobin per cent in the root nodules of leguminous plants helps in nitrogen fixation by

Answer: Option A

Leghemoglobin present in the root nodules of leguminous plants helps in nitrogen fixation by removing oxygen.
Leghemoglobin is an oxygen-carrying phytoglobin found in the nitrogen-fixing root nodules of leguminous plants.
It is produced by these plants in response to the roots being colonized by nitrogen-fixing bacteria, termed rhizobia, as part of the symbiotic interaction between plant and bacterium roots not colonized by Rhizobium do not synthesise leghemoglobin.
The main functions of leghemoglobin are to facilitate oxygen supply to the nitrogen-fixing bacteria and to protect the enzyme, nitrogenase from being inactivated by oxygen.