Which enzyme when made to act on a DNA molecule creates blunt ends/flush ends?

Options

A. A. Sma I
B. B. Hind II
C. C. EcoR I
D. D. Bam HI

Answer

To answer the question about which enzyme creates blunt ends or flush ends when acting on a DNA molecule, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Types of DNA Ends**:
- DNA ends can be categorized as blunt ends (flush ends) or sticky ends (overhangs). Blunt ends are straight cuts across the DNA, while sticky ends have overhanging nucleotides.

2. **Identify the Enzymes**:
- The question provides options, including SMA-1, EcoRI, and BamHI. We need to evaluate which of these enzymes produces blunt ends.

3. **Evaluate SMA-1**:
- SMA-1 is a restriction enzyme that cuts DNA in a way that results in blunt ends. This means that when SMA-1 acts on a DNA molecule, it cuts straight across the double helix, leaving no overhangs.

4. **Evaluate Other Options**:
- EcoRI and BamHI are both restriction enzymes known to produce sticky ends. They cut the DNA in a staggered manner, leaving overhanging nucleotides.

5. **Conclusion**:
- Based on the evaluation, the correct enzyme that creates blunt ends when acting on a DNA molecule is SMA-1.

### Final Answer:
The enzyme that creates blunt ends when made to act on a DNA molecule is **SMA-1**.

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