Question

The process of nitrogen-fixation by bacteria does not take place in the presence of:

• A. The molecular form of hydrogen
• B. The elemental form of oxygen
• C. Water
• D. The elemental form of nitrogen

Answer 1

The correct option is B

The elemental form of oxygen

The correct answer is option B

Explanation of the correct answer:

1. Nitrogen-fixation: It is the process of conversion of atmospheric nitrogen into organically usable nitrates.
2. The process is carried out by specific nitrogen-fixing bacteria like Rhizobium sp, Azotobacter, sp., etc. as they contain the enzyme Nitrogenase, which is vital to the fixation reaction.
3. However, the enzyme does not function in the presence of oxygen. It loses its catalytic activity and the nitrogen-fixation reaction comes to a pause.
4. Thus, the process of nitrogen fixation by bacteria does not take place in the presence of elemental oxygen.

Therefore, the final answer is option B.