Assertion: A ds DNA, tagged with a radioactive molecule (probe) is used in medical diagnosis
Reason :It is complementary to mutated gene

Options

A. If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion
B. It both Assertion & Reason are True but Reason is not a correct explanation of the Assetion
C. If Assertion is True but the Reason is False
D. If both Assertion & Reason are false

Answer

To solve the question regarding the assertion and reason statements, we will analyze both statements step by step.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "A ds DNA, tagged with a radioactive molecule (probe) is used in medical diagnosis."
- This is true. Double-stranded DNA (ds DNA) probes are indeed used in various medical diagnostic techniques, particularly in identifying genetic mutations or abnormalities.

2. **Understanding the Reason**:
- The reason states that "It is complementary to mutated gene."
- This statement is misleading. The radioactive probe is designed to be complementary to the normal gene sequence, not the mutated one. Therefore, if the probe binds, it indicates the presence of the normal gene, while a lack of binding suggests a mutation.

3. **Analyzing the Relationship**:
- The assertion is true, as ds DNA probes are used in medical diagnostics.
- The reason is false because the probe is not complementary to the mutated gene; it is complementary to the normal gene.

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

### Final Answer:
- The assertion is true, and the reason is false.