Enzyme used is gene cloning is

Options

A. RNA dependent RNA polymerase
B. RNA dependent DNA polymerase
C. DNA dependent DNA polymerase
D. DNA dependent RNA polymerase

Answer

To answer the question about the enzyme used in gene cloning, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Gene Cloning**: Gene cloning involves the process of creating copies of a specific gene or DNA sequence. It is a fundamental technique in molecular biology.

2. **Identifying Key Enzymes**: The process of gene cloning requires several enzymes, but the primary ones are restriction endonucleases and DNA ligases.

3. **Role of Restriction Endonucleases**: The first step in gene cloning is the cleavage of foreign DNA. This is done by restriction endonucleases, which cut the DNA at specific sequences.

4. **Ligation of DNA Fragments**: After the foreign DNA is cleaved, it needs to be inserted into a plasmid vector. This is where DNA ligase comes into play. DNA ligase is responsible for joining the DNA fragments together.

5. **Finalizing the Answer**: Among the options provided:
- Option A: RNA dependent RNA polymerase
- Option B: RNA dependent DNA polymerase
- Option C: DNA dependent DNA polymerase
- Option D: DNA dependent RNA polymerase

The relevant enzyme for gene cloning, particularly for ligating the DNA fragments, is DNA ligase, which is often referred to in the context of DNA dependent DNA polymerase for replication purposes.

6. **Conclusion**: The enzyme primarily used in gene cloning is DNA ligase, but since the question asks for a specific option, the closest answer that relates to the cloning process is **Option B: RNA dependent DNA polymerase**.