Leg - haemoglobin is found in the nodules in roots of leguminous plants. It acts as ........ Scavenger and provides ........ Conditions for the action of nitrogenase enzyme.

Options

A. Oxygen , Aerobic
B. Oxygen , Anaerobic
C. `CO_2` Aerobic
D. `CO_2` , Anaerobic

Answer

To solve the question regarding leg-haemoglobin in leguminous plants, we can break down the information step by step.

### Step-by-Step Solution:

1. **Understanding Leg-Hemoglobin**: Leg-haemoglobin is a specialized form of hemoglobin found in the root nodules of leguminous plants. Its primary function is to bind oxygen.

**Hint**: Remember that leg-haemoglobin is similar to regular hemoglobin but serves a specific role in nitrogen-fixing plants.

2. **Role of Rhizobium**: In leguminous plants, nitrogen fixation is facilitated by a symbiotic relationship with the bacteria Rhizobium. This bacteria converts atmospheric nitrogen into a form that plants can use.

**Hint**: Consider the relationship between Rhizobium and leguminous plants; it’s crucial for nitrogen fixation.

3. **Function of Nitrogenase**: The enzyme nitrogenase is essential for the nitrogen fixation process. However, nitrogenase functions optimally in anaerobic conditions (absence of oxygen).

**Hint**: Recall that nitrogenase is sensitive to oxygen and requires a specific environment to function effectively.

4. **Oxygen Scavenger Role**: Leg-haemoglobin acts as an oxygen scavenger. It binds to oxygen, thereby reducing its concentration in the root nodules. This creates an anaerobic environment necessary for nitrogenase to operate.

**Hint**: Think about how leg-haemoglobin helps maintain the right conditions for nitrogen fixation by managing oxygen levels.

5. **Conclusion**: Therefore, leg-haemoglobin acts as an oxygen scavenger and provides anaerobic conditions for the action of the nitrogenase enzyme.

**Final Answer**: Leg-haemoglobin acts as **oxygen scavenger** and provides **anaerobic** conditions for the action of nitrogenase enzyme.

### Final Answer:
Leg-haemoglobin acts as an **oxygen scavenger** and provides **anaerobic** conditions for the action of nitrogenase enzyme.