Which enzyme cuts DNA at specific sites?

Options

A. DNA polymerase
B. Taq-polymerase
C. Topoisomerase
D. Restriction endonuclease

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks which enzyme is responsible for cutting DNA at specific sites. This is a key aspect of molecular biology and biotechnology.

2. **Analyzing the Options**: We have four options to consider:
- **Option A: DNA Polymerase** - This enzyme is involved in DNA synthesis, not in cutting DNA.
- **Option B: Taq Polymerase** - This enzyme is derived from the bacterium Thermus aquaticus and is used in PCR (Polymerase Chain Reaction) for DNA synthesis, not for cutting DNA.
- **Option C: Topoisomerase** - This enzyme helps in unwinding DNA and relieving strain during replication but does not cut DNA at specific sites.
- **Option D: Restriction Endonuclease** - This enzyme specifically recognizes and cuts DNA at particular sequences.

3. **Identifying the Correct Answer**: Among the options, only the restriction endonuclease is known for its ability to cleave DNA at specific sites. This is crucial for various applications in genetic engineering and recombinant DNA technology.

4. **Conclusion**: Therefore, the enzyme that cuts DNA at specific sites is **Restriction Endonuclease**.

**Final Answer**: **Restriction Endonuclease (Option D)**

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