SECTION C (4 MARKS EACH)
Q6.
The following are certain facts regarding biological nitrogen fixation in plants:
1. Oxygen irreversibly inactivates nitrogenase enzyme involved in nitrogen fixation.
2. The nod genes that code for nodulation proteins are activated by NodD.
3. The two components of nitrogenase enzyme complex, the Fe protein and MoFe protein can show catalytic activity independently.
4. During the reaction catalyzed by nitrogenase enzyme, the Fe protein reduces the MoFe protein while the MoFe protein reduces N2.
Which of the following combinations of the above statements are correct:
A. 1, 2, and 3
B. 2, 3 and 4
C. 1, 3, and 4
D. 1,2, and 4