LIFE SCIENCE

Detailed explanation-1: -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. 3. Hence, the presence of leghaemoglobin exhibits a good coordination between host plant and the bacteria.

Detailed explanation-2: -The leghaemoglobin is responsible for creating anaerobic conditions in the root nodules of the legume plant. It acts as oxygen scavenger and protects enzyme nitrogenase from oxygen and helps in proper functioning of the enzyme.

Detailed explanation-3: -The key roles of leghemoglobin are to promote the delivery of oxygen to the nitrogen-fixing bacteria and to shield the nitrogenase enzyme from oxygen inactivation. Leghaemoglobin is a scavenger of oxygen that protects nitrogenase during fixation of nitrogen.

Detailed explanation-4: -So, the correct answer is ‘Clostridium’.