Which of the following is a restriction endonuclease?

Options

A. Hind II
B. Protease
C. Dnase I
D. R Nase

Answer

To determine which of the following options is a restriction endonuclease, we need to understand what restriction endonucleases are and analyze the given options.

### Step-by-Step Solution:

1. **Understanding Restriction Endonucleases**:
- Restriction endonucleases, also known as restriction enzymes, are enzymes that cut DNA at specific sequences. They are primarily obtained from bacteria and are used in molecular biology for DNA manipulation.

2. **Analyzing the Options**:
- The options provided are:
- A) Hind II
- B) Protease
- C) DNase I
- D) RNase

3. **Identifying Each Option**:
- **Hind II**: This is a restriction endonuclease that cuts DNA at specific sequences. It is derived from the bacterium Haemophilus influenzae.
- **Protease**: This enzyme breaks down proteins into smaller peptides or amino acids. It does not cut DNA.
- **DNase I**: This enzyme degrades DNA but is not classified as a restriction endonuclease because it does not cut at specific sequences.
- **RNase**: This enzyme degrades RNA, not DNA, and is not a restriction endonuclease.

4. **Conclusion**:
- Among the options, **Hind II** is the only restriction endonuclease.

### Final Answer:
The correct answer is **Hind II**.