Assertion (A): Germ pores are the regions where intine comes out to form a pollen tube after pollination.
Reason (B): Germ pores are prominent apertures of pollen grains where exine is thin or absent.

Options

A. Both A and R are true and R is the correct explanation of A
B. Both A and R are true but R is not the correct explanation of A
C. A is true but R is false
D. A is false but R is true

Explanation

To solve the question regarding the assertion and reason about germ pores in pollen grains, we can break it down into clear steps:

### Step-by-Step Solution:

1. **Understanding the Assertion (A)**:
- The assertion states that "Germ pores are the regions where intine comes out to form a pollen tube after pollination."
- This means that after the pollen grain lands on the stigma of a flower, the intine (the inner layer of the pollen grain) emerges from the germ pores to form a pollen tube, which is essential for fertilization.

2. **Understanding the Reason (B)**:
- The reason states that "Germ pores are prominent apertures of pollen grains where exine is thin or absent."
- This indicates that germ pores are specific areas on the pollen grain where the outer layer (exine) is either very thin or completely missing, allowing the intine to be exposed.

3. **Analyzing the Structure of Pollen Grains**:
- Pollen grains are composed of two main layers: the outer layer called exine, which is tough and made of sporopollenin, and the inner layer called intine, which is softer and made of cellulose and pectin.
- Germ pores are indeed the locations where the exine is less robust, facilitating the emergence of the intine.

4. **Evaluating the Relationship Between Assertion and Reason**:
- Both the assertion and reason are correct statements about pollen grains.
- However, the reason does not provide a direct explanation for the assertion. While it describes the structure of germ pores, it does not explain why the intine emerges from these pores to form a pollen tube.

5. **Conclusion**:
- Therefore, the correct option is that both the assertion and reason are true, but the reason is not the correct explanation of the assertion.

### Final Answer:
Both Assertion (A) and Reason (B) are true, but Reason (B) is not the correct explanation of Assertion (A).

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