Algal zone is characteristic of
(a) Coralloid root of Cycas
(b) Normal root of Cycas
(c) Normal root of Pinus
(d) Mycorrhizal root of Pinus

Options

A. Coralloid root of Cycas
B. Normal root of Cycas
C. Normal root of Pinus
D. Mycorrhizal root of Pinus.

Answer

To solve the question regarding the characteristic of the algal zone, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Algal Zone**:
- The algal zone refers to a specific region in certain roots where cyanobacteria (also known as blue-green algae) reside. This zone is crucial for nitrogen fixation.

2. **Analyzing the Options**:
- **(a) Coralloid root of Cycas**: Coralloid roots are specialized structures found in Cycas that harbor cyanobacteria for nitrogen fixation.
- **(b) Normal root of Cycas**: Normal roots do not have the algal zone associated with them.
- **(c) Normal root of Pinus**: Similar to the normal root of Cycas, the normal root of Pinus does not have an algal zone.
- **(d) Mycorrhizal root of Pinus**: Mycorrhizal roots are associated with fungi, not cyanobacteria, and do not feature an algal zone.

3. **Identifying the Correct Answer**:
- Based on the analysis, the algal zone is characteristic of the coralloid root of Cycas, as it is specifically associated with cyanobacteria for nitrogen fixation.

4. **Conclusion**:
- Therefore, the correct answer is **(a) Coralloid root of Cycas**.

### Final Answer:
The algal zone is characteristic of **(a) Coralloid root of Cycas**.

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