Assertion: Many physical and chemical agents induce inheritable mutations.
Reason: Germ cells are not immune to the changes in environmental factors.

Options

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

Answer

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "Many physical and chemical agents induce inheritable mutations."
- Mutations are changes in the DNA sequence, which can be inherited (passed to the next generation) or non-inherited (remain within a single generation).
- Physical agents (like UV rays, gamma rays, and x-rays) and chemical agents (like alkylating agents) can cause these mutations.
- Therefore, the assertion is **true**.

2. **Understanding the Reason**:
- The reason states that "Germ cells are not immune to the changes in environmental factors."
- Germ cells (sperm and egg cells) are indeed affected by environmental factors, which can lead to mutations.
- If germ cells were immune to environmental changes, mutations would not be inherited, contradicting the assertion.
- Thus, the reason is also **true**.

3. **Evaluating the Relationship**:
- The assertion and reason are both true, but we need to determine if the reason correctly explains the assertion.
- The reason explains that germ cells are affected by environmental factors, which allows for the inheritance of mutations.
- However, the reason does not directly explain why many physical and chemical agents induce inheritable mutations; it merely states that germ cells are affected by environmental changes.
- Therefore, the reason is **not a correct explanation** for the assertion.

4. **Conclusion**:
- Both the assertion and reason are true, but the reason does not serve as a correct explanation for the assertion.
- The correct option is: **Both assertion and reason are true; reason is not the correct explanation of assertion.**