Enzyme that cuts DNA at specific sites is

Options

A. Restriction endonuclease
B. DNA ligase
C. DNA polymerase
D. Reverse transcriptase

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the name of the enzyme that cuts DNA at specific sites. This indicates that we are looking for an enzyme involved in molecular biology, particularly in DNA manipulation.

2. **Identifying the Enzyme**: In the context of recombinant DNA technology, the enzyme that is commonly used to cut DNA at specific sequences is known as a restriction enzyme or restriction endonuclease.

3. **Function of Restriction Enzymes**: Restriction enzymes act as molecular scissors. They recognize specific sequences in the DNA, known as palindromic sequences, and cut the DNA at these sites.

4. **Example of a Restriction Enzyme**: A well-known example of a restriction enzyme is EcoRI, which recognizes the palindromic sequence GAATTC. It cuts between the G and the A on both strands of the DNA.

5. **Conclusion**: Based on the function and examples provided, the correct answer to the question is that the enzyme that cuts DNA at specific sites is called a restriction endonuclease.

**Final Answer**: The enzyme that cuts DNA at specific sites is called a restriction endonuclease.

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