Which enzyme is known an 'molecular scissors'?

Answer

**Step-by-Step Solution:**

1. **Understanding the Term "Molecular Scissors":** The term "molecular scissors" refers to enzymes that can cut molecules, specifically DNA. This is important in genetic engineering where we need to manipulate DNA.

2. **Identifying the Enzymes:** The enzymes that perform this cutting action are known as restriction enzymes. They are crucial for creating recombinant DNA by cutting DNA at specific sites.

3. **Types of Restriction Enzymes:** There are two main types of restriction enzymes:
- **Endonucleases:** These enzymes cut DNA at specific internal sites within the molecule.
- **Exonucleases:** These enzymes cut DNA from the ends of the molecule.

4. **Conclusion:** Therefore, the enzymes known as "molecular scissors" are collectively referred to as restriction enzymes, with restriction endonucleases and restriction exonucleases being specific examples.

**Final Answer:** The enzyme known as "molecular scissors" is the restriction enzyme.

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