Question

In root nodules of legumes, leg-haemoglobin is important because it

• A. Transports oxygen to the root nodule
• B. Acts as an oxygen scavenger
• C. Provides energy to the nitrogen fixing bacterium
• D. Acts as a catalyst in transamination

Answer 1

The correct option is B

Acts as an oxygen scavenger

In plants colonised by Rhizobium , the presence of oxygen in the root nodules would reduce the activity of the oxygen-sensitive nitrogenase - an enzyme responsible for the fixation of atmospheric nitrogen. Leghemoglobin buffers the concentration of free oxygen in the cytoplasm of infected plant cells to ensure the proper function of root nodules.