Which one of these is not a tool of recombinant DNA technology

Options

A. Restriction enzyme
B. Vector
C. Polymerase enzyme
D. Introns

Answer

To determine which of the given options is not a tool of recombinant DNA technology, we will analyze each option step by step.

### Step-by-Step Solution:

1. **Identify the Options**:
- Option 1: Restriction enzyme
- Option 2: Vector
- Option 3: Polymerase enzyme
- Option 4: Introns

2. **Analyze Option 1: Restriction Enzyme**:
- Restriction enzymes, also known as molecular scissors, are crucial in recombinant DNA technology. They cut DNA at specific sequences, allowing for the manipulation of DNA fragments.
- **Conclusion**: This is a tool of recombinant DNA technology.

3. **Analyze Option 2: Vector**:
- Vectors are DNA molecules used to transport foreign genetic material into a host cell. They are essential for cloning DNA and transferring DNA into cells.
- **Conclusion**: This is also a tool of recombinant DNA technology.

4. **Analyze Option 3: Polymerase Enzyme**:
- Polymerase enzymes, such as DNA ligase, are involved in joining DNA fragments together after they have been cut by restriction enzymes. They play a critical role in the synthesis of new DNA strands.
- **Conclusion**: This is another tool of recombinant DNA technology.

5. **Analyze Option 4: Introns**:
- Introns are non-coding regions of RNA that are removed during RNA processing. They do not play a role in the actual manipulation or cloning of DNA in recombinant DNA technology.
- **Conclusion**: This is not a tool of recombinant DNA technology.

### Final Answer:
The option that is not a tool of recombinant DNA technology is **Option 4: Introns**.

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