Pick out the correct statement from the following in relation to gel electrophoresis

Options

A. The smallest DNA pieces travel the shorter distances
B. The larger DNA pieces are close to the top of the gel
C. The larger DNA pieces travel the longer distances
D. The shorter DNA pieces are close to the top of the gel

Answer

**Step-by-Step Solution:**

1. **Understanding Gel Electrophoresis**: Gel electrophoresis is a technique used to separate DNA, RNA, and proteins based on their size. The gel acts as a medium through which these molecules can move.

2. **Mechanism of Separation**: In gel electrophoresis, smaller DNA fragments move faster and travel longer distances through the gel compared to larger fragments. This is because smaller fragments can easily navigate through the pores of the gel.

3. **Direction of Movement**: All DNA fragments are negatively charged and move towards the positive end of the gel when an electric current is applied.

4. **Positioning of DNA Fragments**:
- Smaller DNA fragments will be found further down the gel (closer to the positive end) because they move faster.
- Larger DNA fragments will remain closer to the top of the gel, as they move slower and cannot traverse the gel as easily.

5. **Evaluating the Statements**:
- **Statement 1**: "The smallest DNA pieces travel shorter distance." - This is incorrect. Smaller pieces travel longer distances.
- **Statement 2**: "Larger DNA pieces are close to the top of the gel." - This is correct. Larger pieces do remain near the top.
- **Statement 3**: "Larger DNA pieces travel longer distance." - This is incorrect. Larger pieces travel shorter distances.
- **Statement 4**: "The shorter DNA pieces are close to the top of the gel." - This is incorrect. Shorter pieces are found further down the gel.

6. **Conclusion**: The correct statement in relation to gel electrophoresis is that larger DNA pieces are close to the top of the gel.

**Final Answer**: The correct statement is: "Larger DNA pieces are close to the top of the gel."

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