A: DNA ligase plays an important role in recombinant DNA technology.
R: The linking of antibiotic resistance gene with plasmid vector became possible by enzyme DNA ligase

Options

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

Answer

To solve the question regarding the assertion and reason related to DNA ligase in recombinant DNA technology, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Assertion (A)**:
- The assertion states that "DNA ligase plays an important role in recombinant DNA technology."
- **Explanation**: DNA ligase is an enzyme that facilitates the joining of DNA strands by catalyzing the formation of phosphodiester bonds. This is crucial in recombinant DNA technology where different DNA fragments need to be joined together to create recombinant DNA.

2. **Understanding the Reason (R)**:
- The reason states that "The linking of antibiotic resistance gene with plasmid vector became possible by enzyme DNA ligase."
- **Explanation**: In recombinant DNA technology, DNA ligase is used to link an antibiotic resistance gene to a plasmid vector. This process involves cutting the plasmid and the gene with restriction enzymes and then using DNA ligase to join them together, forming a new recombinant plasmid that can be introduced into host cells.

3. **Evaluating the Truth of Assertion and Reason**:
- Both the assertion and the reason are true statements.
- The reason correctly explains the assertion because DNA ligase is indeed the enzyme that facilitates the linking of the antibiotic resistance gene to the plasmid vector.

4. **Conclusion**:
- Since both the assertion and reason are true, and the reason is the correct explanation of the assertion, the correct answer is that both statements are true and the reason is the correct explanation of the assertion.

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

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