In root nodules of leguminous plants, the pigment leghemoglobin that gives pink colour to the nodules, is present in the

Options

A. The wall of bacteria
B. The wall of host cell
C. The cytoplasm of host cell
D. Between bacteroids and surrounding

Answer

To solve the question regarding the presence of leghemoglobin in root nodules of leguminous plants, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Context**:
- Leguminous plants, such as pulses, form root nodules that house nitrogen-fixing bacteria (like Rhizobium). These nodules are crucial for the plant's ability to utilize atmospheric nitrogen.

2. **Identifying Leghemoglobin**:
- Leghemoglobin is a pigment that gives root nodules their characteristic pink color. It plays a vital role in oxygen transport within the nodules, ensuring that the bacteria have a suitable environment for nitrogen fixation.

3. **Analyzing the Options**:
- The options provided are:
a. Wall of bacteria
b. Wall of host cell
c. Cytoplasm of host cell between bacteroids and surroundings
- We need to determine where leghemoglobin is specifically located among these options.

4. **Evaluating Each Option**:
- **Wall of Bacteria**: Leghemoglobin is not found in the bacterial cell wall.
- **Wall of Host Cell**: Similarly, leghemoglobin is not located in the wall of the host plant's cells.
- **Cytoplasm of Host Cell**: This option suggests that leghemoglobin is located in the cytoplasm of the host cell, specifically in the space surrounding the bacteria (bacteroids).

5. **Conclusion**:
- Based on the analysis, leghemoglobin is indeed present in the cytoplasm of the host cell, where it interacts with the bacteroids. Therefore, the correct answer is **the cytoplasm of the host cell**.

### Final Answer:
Leghemoglobin that gives pink color to the nodules is present in the **cytoplasm of the host cell**.

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