In recombinant DNA technology, a plasmid vector is cleaved by

Options

A. Modified DNA ligase
B. A heated alkaline solution
C. The same enzyme that cleaves donor DNA
D. Different enzyme that cleaved the donor DNA

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the process of cleaving a plasmid vector in recombinant DNA technology. Cleaving refers to the cutting of DNA.

2. **Identifying Plasmid Vector**: A plasmid vector is a circular double-stranded DNA molecule used to transfer genetic material into a host cell.

3. **Role of Enzymes**: In recombinant DNA technology, specific enzymes are used to cut DNA. The two main types of enzymes that can cleave DNA are:
- **Exonucleases**: These enzymes cut DNA from the ends of the molecule.
- **Endonucleases**: These enzymes cut DNA at specific internal sites within the molecule.

4. **Commonly Used Enzyme**: In recombinant DNA technology, **endonucleases** are predominantly used, particularly a subtype known as **restriction endonucleases**. These enzymes recognize specific sequences in the DNA and cut at those sites.

5. **Cutting the Desired Gene**: The desired gene is cut from the donor DNA using a restriction endonuclease. The same restriction endonuclease is then used to cut the plasmid vector to create compatible ends for the insertion of the desired gene.

6. **Conclusion**: The correct answer to the question is that a plasmid vector is cleaved by the same enzyme that cleaves the donor DNA, which is a restriction endonuclease.

### Final Answer:
In recombinant DNA technology, a plasmid vector is cleaved by the same enzyme that cleaves the donor DNA, which is a restriction endonuclease.

---