Assertion: The recombinant DNA molecule cannot be created, unless one cuts the vector & source DNA with same restriction enzyme
Reason :When cuts by same enzyme both will have same sticky ends, that can be joined by DNA ligase

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 about recombinant DNA technology, we will break it down step by step.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that a recombinant DNA molecule cannot be created unless both the vector DNA and the source DNA are cut with the same restriction enzyme. This is true because the compatibility of the ends of the DNA fragments is crucial for successful ligation.

**Hint**: Think about why the ends of DNA need to match for successful joining.

2. **Understanding the Reason**:
- The reason provided states that when both DNA strands are cut by the same restriction enzyme, they will produce the same sticky ends. This is essential because sticky ends can easily anneal to each other, allowing for the formation of a recombinant DNA molecule when DNA ligase is used to join them.

**Hint**: Consider what happens at the molecular level when DNA is cut by the same enzyme.

3. **Illustrating the Process**:
- When a restriction enzyme like EcoRI is used, it recognizes a specific palindromic sequence (e.g., GAATTC) and cuts the DNA at that site. This results in sticky ends on both the vector and the source DNA.
- If both DNA fragments are cut with EcoRI, they will have complementary sticky ends that can bind together.

**Hint**: Visualize how the sticky ends of two DNA fragments can fit together like puzzle pieces.

4. **Conclusion**:
- Since both the assertion and reason are true and the reason correctly explains the assertion, we conclude that the answer to the question is that both the assertion and reason are true, and the reason is a correct explanation of the assertion.

**Hint**: Reflect on the relationship between the assertion and reason to determine their truthfulness.

### Final Answer:
Both the assertion and reason are true, and the reason is a correct explanation of the assertion.

### Answer Option:
- Option A: Both assertion and reason are true, and reason is a correct explanation of the assertion.