A : Fucus, a brown alga shows oogamy.
R: Female gamete is quite large as compare to male gamete.

Options

A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then mark (1)
B. If both Assertion & Reason are true and the reason is not the correct explanation of the assertion, then mark (2)
C. If Assertion is true statements but Reason is false then mark (3)
D. If both Assertion and Reason are false statements, then mark (4)

Answer

To solve the assertion and reason question regarding Fucus, a brown alga that shows oogamy, we can break it down into the following steps:

### Step-by-Step Solution:

1. **Understanding the Terms:**
- **Oogamy:** This is a form of sexual reproduction involving the fusion of two distinct types of gametes: a large, non-motile female gamete (egg) and a small, motile male gamete (sperm).
- **Fucus:** A genus of brown algae that reproduces through this method.

2. **Assertion Analysis:**
- The assertion states that "Fucus, a brown alga shows oogamy." This is true because Fucus produces two different types of gametes: a large female gamete and a smaller male gamete.

3. **Reason Analysis:**
- The reason states that "The female gamete is quite large as compared to the male gamete." This is also true, as in oogamous reproduction, the female gamete is significantly larger and non-motile, while the male gamete is smaller and motile.

4. **Conclusion:**
- Both the assertion and the reason are correct. The assertion correctly identifies the reproductive method of Fucus, and the reason accurately describes the size difference between the male and female gametes.

5. **Final Answer:**
- Since both the assertion and reason are true, the correct conclusion is that both statements are valid, confirming that Fucus exhibits oogamy with the characteristic size difference between its gametes.