The characteristic feature of leghaemoglobin are:
A. It is a source of energy
B. It is a pinkish coloured pigment found in nodules
C. Activated by presence of Mgions
D. It protects nitrogen fixing enzyme nitrogenase from oxygen :

Options

A. A, B and C are correct
B. A and B are correct
C. B and D are correct
D. A and C are correct

Answer

To determine the characteristic features of leghaemoglobin, we can analyze each statement provided in the question:

1. **Statement A: It is a source of energy.**
- This statement is incorrect. Leghaemoglobin is not a source of energy; rather, it functions primarily as an oxygen scavenger in the root nodules of leguminous plants.

2. **Statement B: It is a pinkish coloured pigment found in nodules.**
- This statement is correct. Leghaemoglobin is indeed a pinkish pigment that is found in the root nodules of leguminous plants. Its color is due to its structural similarity to hemoglobin.

3. **Statement C: Activated by presence of Mg ions.**
- This statement is incorrect. Leghaemoglobin does not require magnesium ions for its activation or function. Its role is primarily related to oxygen management in the nodules.

4. **Statement D: It protects nitrogen-fixing enzyme nitrogenase from oxygen.**
- This statement is correct. Leghaemoglobin plays a crucial role in protecting the nitrogen-fixing enzyme, nitrogenase, from the harmful effects of oxygen, allowing the nitrogen fixation process to occur efficiently.

Based on the analysis:
- The correct statements about leghaemoglobin are B and D.

**Final Answer: The characteristic features of leghaemoglobin are B (It is a pinkish coloured pigment found in nodules) and D (It protects nitrogen-fixing enzyme nitrogenase from oxygen).**