In root nodules of legumes, leghaemoglobin is important because it

Options

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

### Step-by-Step Solution:

1. **Understanding the Role of Leghemoglobin**:
- Leghemoglobin is a protein found in the root nodules of legumes. It is similar to hemoglobin found in blood, but its primary function is related to nitrogen fixation.

2. **Function of Leghemoglobin**:
- The main role of leghemoglobin is to regulate oxygen levels within the root nodules. It binds to oxygen and helps maintain a low concentration of free oxygen.

3. **Importance of Anaerobic Conditions**:
- Nitrogen-fixing bacteria, such as Rhizobium, reside in the root nodules and require anaerobic conditions to effectively fix nitrogen. The enzyme nitrogenase, which is crucial for this process, is sensitive to oxygen and can be inactivated by it.

4. **Oxygen Scavenging**:
- By acting as an oxygen scavenger, leghemoglobin removes excess oxygen from the root nodules, thus creating an environment suitable for the nitrogenase enzyme to function optimally.

5. **Conclusion**:
- Therefore, the importance of leghemoglobin in root nodules of legumes is primarily that it acts as an oxygen scavenger, allowing nitrogen fixation to occur efficiently.

### Final Answer:
In root nodules of legumes, leghaemoglobin is important because it acts as an oxygen scavenger.