The cutting of DNA by restriction endonucleases results in the fragments of DNA. These fragments can be separated by a technique known as

Options

A. PCR
B. molecular diagonsis
C. isolation of DNA
D. gel electrophoresis

Answer

**Step-by-Step Solution:**

1. **Understanding the Process of DNA Cutting:**
- DNA is cut into fragments by enzymes known as restriction endonucleases. These enzymes recognize specific sequences in the DNA and cleave it at those sites.

2. **Result of DNA Cutting:**
- The cutting of DNA results in multiple fragments of varying lengths. These fragments need to be separated for further analysis or experimentation.

3. **Identifying the Separation Technique:**
- To separate these DNA fragments, we need a technique that can effectively differentiate them based on size. The most common method used for this purpose is gel electrophoresis.

4. **Explanation of Gel Electrophoresis:**
- Gel electrophoresis involves the use of an agarose gel as a medium. The DNA fragments are loaded into wells in the gel, and an electric current is applied.
- DNA is negatively charged due to its phosphate backbone, so when the current is applied, the fragments move towards the positive electrode (anode).
- Smaller fragments move faster and travel further through the gel than larger fragments, allowing for separation based on size.

5. **Conclusion:**
- The technique used to separate the DNA fragments produced by restriction endonucleases is called gel electrophoresis.

**Final Answer:**
The fragments of DNA can be separated by a technique known as **gel electrophoresis**.

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