DNA fragments generated by restriction endonucleases in a chemical reaction can be separated by

Options

A. Restriction mapping
B. Centrifugation
C. Polymerase chain reaction
D. Electrophoresis

Answer

To answer the question regarding how DNA fragments generated by restriction endonucleases can be separated, follow these steps:

### Step-by-Step Solution:

1. **Understanding Restriction Endonucleases**:
- Restriction endonucleases are enzymes that cut DNA at specific sequences, resulting in fragments of varying lengths.

2. **Identifying the Separation Technique**:
- The question provides four options: restriction mapping, centrifugation, polymerase chain reaction (PCR), and electrophoresis. We need to determine which of these techniques is used to separate DNA fragments.

3. **Evaluating Each Option**:
- **Restriction Mapping**: This technique helps to determine the locations of restriction sites within a DNA molecule but does not physically separate the fragments.
- **Centrifugation**: This method separates molecules based on their mass and density but is not typically used for separating DNA fragments.
- **Polymerase Chain Reaction (PCR)**: PCR is a technique used to amplify DNA, not to separate DNA fragments.
- **Electrophoresis**: This is a technique where DNA fragments are separated based on their size. DNA is negatively charged and moves towards the positive electrode when an electric current is applied.

4. **Conclusion**:
- The correct method for separating DNA fragments generated by restriction endonucleases is **electrophoresis**.

### Final Answer:
DNA fragments generated by restriction endonucleases in a chemical reaction can be separated by **electrophoresis**.

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