From the following identify the restriction enzyme that is credited as the 1st one to be isolated .

Options

A. EcoRI
B. Barn HI
C. Hind II
D. Smal

Answer

To identify the restriction enzyme that is credited as the first one to be isolated, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Restriction Enzymes**:
- Restriction enzymes, also known as restriction endonucleases, are proteins that cut DNA at specific sequences. They are primarily found in prokaryotes, such as bacteria.

2. **Identifying the Options**:
- The options given are Eco R1, BAM H1, HIND II, and SMA I. We need to determine which of these was the first restriction enzyme to be isolated.

3. **Historical Context**:
- The first restriction enzyme to be discovered and isolated was Hind II, which was derived from the bacterium Haemophilus influenzae.

4. **Naming Convention**:
- The naming of restriction enzymes follows a specific convention: the first letter represents the genus of the bacterium, and the next two letters represent the species. For example, "Hind" comes from Haemophilus influenzae.

5. **Conclusion**:
- Based on historical records and the naming conventions, the first restriction enzyme to be isolated is **Hind II**.

### Final Answer:
The restriction enzyme credited as the first one to be isolated is **Hind II**.

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