In genetic engineering, restriction enzymes cleave the DNA at a specific site known as:

Options

A. non-specific sites
B. recognition sites
C. promoter sites
D. sense sites

Explanation

### Step-by-Step Solution:

1. **Understanding Restriction Enzymes**:
- Restriction enzymes, also known as restriction endonucleases, are proteins that cut DNA at specific sequences. They play a crucial role in genetic engineering by allowing scientists to manipulate DNA.

2. **Identifying the Cleavage Site**:
- These enzymes recognize specific sequences of nucleotides in the DNA. The site where the restriction enzyme cuts the DNA is known as the recognition site.

3. **Characteristics of Recognition Sites**:
- Recognition sites are highly specific to each restriction enzyme. This means that each enzyme will only cleave DNA at its unique recognition sequence, which is typically a palindromic sequence of nucleotides.

4. **Conclusion**:
- Therefore, in genetic engineering, the specific site where restriction enzymes cleave the DNA is called the **recognition site**.

### Final Answer:
In genetic engineering, restriction enzymes cleave the DNA at a specific site known as the **recognition site**.

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