Assertion: Amphibian males and females produce lot of gamates.
Reason: Males lack copulatory organ in amphibians.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion.
B. If both assertion and reason are true but reason is not the correct explanation of assertion.
C. If assertion is true but reason is false.
D. If both assertion and reason are false.

Explanation

To solve the question, we need to analyze both the assertion and the reason provided.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "Amphibian males and females produce a lot of gametes."
- This is true because amphibians typically undergo external fertilization, which requires a large number of gametes to increase the chances of successful fertilization in the aquatic environment.

2. **Understanding the Reason**:
- The reason states that "Males lack copulatory organs in amphibians."
- This is also true. In most amphibians, males do not have specialized copulatory organs. Instead, they release sperm over the eggs as they are laid, which is facilitated by their reproductive anatomy.

3. **Evaluating the Relationship**:
- While both statements are true, we need to determine if the reason provided explains the assertion.
- The assertion about the production of a lot of gametes is related to the method of fertilization (external), not directly because males lack copulatory organs. Therefore, the reason does not explain why amphibians produce a lot of gametes.

4. **Conclusion**:
- Both the assertion and reason are true, but the reason does not provide a correct explanation for the assertion.
- Thus, the answer is: Both assertion and reason are true, but the reason is not the correct explanation of the assertion.

### Final Answer:
- The correct answer is option B: Both assertion and reason are true, but reason is not the correct explanation of assertion.