Assertion : Metamorphosis in frog said to be progressive.
Reason : Metamorphosis in frog is controlled by thyroxin hormone.

Options

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

Answer

To analyze the assertion and reason provided in the question, we will break down the statements and evaluate their validity step by step.

### Step 1: Understand the Assertion
- **Assertion**: "Metamorphosis in frog said to be progressive."
- **Explanation**: Metamorphosis in frogs is indeed progressive. This means that during the life cycle of a frog, the organism undergoes significant changes from a simpler form (tadpole) to a more complex form (adult frog). This process involves the development of advanced characteristics, such as the formation of limbs and the transition from aquatic to terrestrial life.

### Step 2: Understand the Reason
- **Reason**: "Metamorphosis in frog is controlled by thyroxin hormone."
- **Explanation**: The metamorphosis of frogs is indeed regulated by the thyroxin hormone, which is produced by the thyroid gland. Thyroxin plays a crucial role in the growth and development of the frog during its metamorphic transition, influencing the physiological changes that occur.

### Step 3: Evaluate the Relationship
- The assertion is true because metamorphosis in frogs is progressive.
- The reason is also true because thyroxin is responsible for regulating this metamorphosis.
- However, the reason does not directly explain why the metamorphosis is considered progressive; it merely states a fact about the hormonal control involved.

### Conclusion
- Both the assertion and the reason are true.
- The reason is not a correct explanation of the assertion.

### Final Answer
The correct option is: **Both assertion and reason are true, and reason is not a correct explanation of assertion.**

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