From isolated DNA from a cell culture with seven desired genes, DNA segment can be excised by molecular scissors or chemical scalpels what biotechnologists call as

Options

A. Polymerase enzymes
B. DNA ligase
C. Restriction enzymes
D. Helicase

Answer

To answer the question regarding what biotechnologists call the molecular scissors or chemical scalpels used to excise DNA segments, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Terms**: The question mentions "molecular scissors" and "chemical scalpels." These terms are often used in biotechnology to refer to specific tools that can cut DNA.

2. **Identifying the Options**: The options provided are:
- A) Polymerase enzyme
- B) DNA ligase
- C) Restriction enzyme
- D) Helicase

3. **Analyzing Each Option**:
- **Polymerase enzyme**: This enzyme is involved in DNA replication and synthesis but does not cut DNA.
- **DNA ligase**: This enzyme is responsible for joining DNA fragments together but does not cut DNA.
- **Restriction enzyme**: These are enzymes that cut DNA at specific sequences, often referred to as "restriction sites." They are indeed known as molecular scissors.
- **Helicase**: This enzyme unwinds the DNA double helix but does not cut it.

4. **Conclusion**: Based on the analysis, the correct answer is **C) Restriction enzyme**. These enzymes act as molecular scissors by excising DNA segments at specific sites.

5. **Final Answer**: The biotechnologists call these molecular scissors or chemical scalpels **restriction enzymes**.