Restriction endonuclease is employed for cutting

Options

A. A single stranded DNA
B. Double stranded DNA
C. RNA fragment
D. mRNA

Answer

**Step-by-Step Solution:**

1. **Understanding Restriction Endonucleases**:
- Restriction endonucleases, also known as restriction enzymes, are proteins that can cut DNA at specific sequences.

2. **Identifying the Target of Restriction Endonucleases**:
- These enzymes recognize specific nucleotide sequences within the DNA, known as restriction sites.

3. **Mechanism of Action**:
- When a restriction endonuclease acts on DNA, it makes cuts in the sugar-phosphate backbone of the DNA strands. Each enzyme typically cuts both strands of the double helix, resulting in two incisions.

4. **Types of Nucleic Acids**:
- The question provides options: single stranded DNA, double stranded DNA, RNA fragment, and mRNA.

5. **Determining the Correct Answer**:
- Restriction endonucleases are specifically designed to cut double stranded DNA. They do not cut single stranded DNA or RNA (including mRNA).

6. **Conclusion**:
- Therefore, the correct answer to the question is **double stranded DNA**.

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