During biological nitrogen fixation, inactivation of nitrogenase by oxygen poisoning is prevented by

1. Leghaemoglobin

2. Xanthophylls

3. Carotene

4. Cytochrome

For its action, nitrogenase requires :
1.  Light
2.  Mn²⁺
3.  Super oxygen radicals
4.  High input of energy

Leguminous plants are able to fix atmospheric nitrogen through the process of symbiotic nitrogen fixation. Which one of the following statements is not correct during this process of nitrogen fixation -

1. Nodules act as sites for nitrogen fixation

2. The enzyme nitrogenase catalyses the conversion of atmospheric N₂ to NH₃

3. Nitrogenase is insensitive to oxygen

4. Leghaemoglobin scavenges oxygen and is pinkish in colour

Roots of which plant contains a pink pigment which have affinity for oxygen :
1.  Carrot
2.  Soyabean
3.  Mustard
4.  Radish