A red pigment present in the root nodules of leguminous plants is known as

Options

A. Phycoerythrin
B. Bacteriochlorophyll
C. Leghaemoglobin
D. Bacterioviridin.

Answer

To answer the question regarding the red pigment present in the root nodules of leguminous plants, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Context**: The question asks for a red pigment found specifically in the root nodules of leguminous plants. These plants often have a symbiotic relationship with nitrogen-fixing bacteria.

2. **Identify the Options**: The options given are:
- A) Phycoerythrin
- B) Bacterioclorophyll
- C) Leg hemoglobin
- D) Bacterioviridin

3. **Analyze Each Option**:
- **Option A: Phycoerythrin**: This is a red pigment found in red algae, not in leguminous plants. It is involved in photosynthesis in those algae. Therefore, this option is incorrect.
- **Option B: Bacterioclorophyll**: This is a photosynthetic pigment found in certain autotrophic bacteria, particularly purple sulfur and non-sulfur bacteria. It is not related to leguminous plants. Thus, this option is also incorrect.
- **Option C: Leg hemoglobin**: This is indeed a red pigment found in the root nodules of leguminous plants. It acts as an oxygen carrier and is crucial for the symbiotic relationship between the plants and nitrogen-fixing bacteria like Rhizobium. This option is correct.
- **Option D: Bacterioviridin**: This pigment is found in photosynthetic green sulfur bacteria and is not related to leguminous plants. Therefore, this option is incorrect.

4. **Conclusion**: After analyzing all the options, we find that the correct answer is **C) Leg hemoglobin**.

### Final Answer:
The red pigment present in the root nodules of leguminous plants is known as **Leg hemoglobin**.

---