NEET BIOLOGY

Detailed explanation-1: -Final Answer: During biological nitrogen fixation, inactivation of nitrogenase by oxygen poisoning is prevented by leghemoglobin.

Detailed explanation-2: -Leghaemoglobin is a hemoprotein as, like haemoglobin, It has 10 times affinity in oxygen more than haemoglobin. It is found in the root nodules of leguminous plant Aad nitrogen-fixing bacterias are aerobic so they need to oxygen for respiration. Hence, leghaemoglobin protect the nitrogenase.

Detailed explanation-3: -Leghaemoglobin is found in the nodules of leguminous plants. 2. The main functions of leghemoglobin are (1) to facilitate oxygen supply to the nitrogen fixing bacteria and (2) to protect the enzyme, nitrogenase from being inactivated by oxygen.

Detailed explanation-4: -Leghemoglobins accumulate to millimolar concentrations in the cytoplasm of infected plant cells prior to nitrogen fixation and are thought to buffer free oxygen in the nanomolar range, avoiding inactivation of oxygen-labile nitrogenase while maintaining high oxygen flux for respiration.

Detailed explanation-5: -Thus, the correct answer is ‘N2-fixation.