The first restriction endonuclease enzyme is

Options

A. Hind-II
B. Hind-III
C. EcoRI
D. Bam`H_(1)`

Answer

### Step-by-Step Solution:

1. **Understanding Restriction Endonucleases**:
- Restriction endonucleases are enzymes that recognize specific nucleotide sequences in DNA and cleave both strands at or near these sites. This property makes them essential tools in molecular biology for DNA manipulation.

2. **Identifying the First Restriction Endonuclease**:
- Among the options provided (HIN2, HIN3, ECO-R1, BAM-H1), we need to identify which one was the first to be discovered and isolated.

3. **Researching HIN2**:
- HIN2 is known to be the first restriction endonuclease that was isolated. It was derived from the bacterium *Haemophilus influenzae* Rd strain 2.

4. **Conclusion**:
- Based on the information gathered, the first restriction endonuclease enzyme is **HIN2**.

### Final Answer:
The first restriction endonuclease enzyme is **HIN2**.

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