Assertion : In a tadpole, if thyroid is cut, metamorphosis stops.
Reason : TSH is not secreted.

Options

A. If both Assertion and Reason are true and Reason is correct explanation of Assertion.
B. If both Assertion and Reason are true but Reason is not correct explanation of Assertion.
C. If Assertion is true but Reason is false.
D. If both Assertion and Reason are false.

Answer

To solve the question, we will analyze the assertion and the reason provided.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that if the thyroid gland is cut in a tadpole, metamorphosis stops.
- This is true because the thyroid gland produces thyroxine, a hormone essential for the process of metamorphosis in tadpoles.

2. **Understanding the Reason**:
- The reason given is that TSH (Thyroid Stimulating Hormone) is not secreted.
- This statement is misleading. While TSH is indeed important for stimulating the thyroid gland to produce thyroxine, the assertion does not depend on the secretion of TSH but rather on the presence of thyroxine itself.

3. **Evaluating the Truth of the Statements**:
- The assertion is true because without the thyroid gland, thyroxine cannot be produced, halting metamorphosis.
- The reason is false because the cessation of metamorphosis is due to the lack of thyroxine, not directly because TSH is not secreted.

4. **Conclusion**:
- Since the assertion is true and the reason is false, the correct answer is that the assertion is true and the reason is false.

### Final Answer:
The correct option is: **Assertion is true and Reason is false.**

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