Write a not on symbiotic nitrogen fixation.

Explanation

Symbiotic nitrogen fixing bacteria : These bacteria are found associated with organs of plants e.g. Rhizobium leguminisarum is found in nudules of roots of leguminous plants. Franka is found in the roots of alnus, Xanthomonas is found in leaves of ardicia These vacteria convert atmospheric nitrogen into nitrates. Some of the nitrates are used by acteria and rest are absorbed by the plant.

The nodules of legunious plants are of pink colour internally due to leghaemoglobin present between cell membrane of host cell and bacteroids Leghaemoglobin is a scavanger os oxygen and protects nitrogenase, which is functional under anaerobic conditions.