Question

Which technique is used to separate and analyze DNA fragments that are of different lengths?

• A. Gel electrophoresis
• B. DNA sequencing
• C. Site-directed mutagenesis
• D. Polymerase chain reaction (PCR)

Hint:

Gel electrophoresis is a powerful tool in molecular biology for separating DNA fragments, allowing scientists to analyze the size and integrity of DNA samples.

Answer 1

The Correct Option is A

The technique used to separate and analyze DNA fragments based on their size (length) is \textit{gel electrophoresis}. This method uses an electric field to move DNA fragments through a gel matrix. Smaller fragments move faster, while larger fragments move slower, allowing the separation of DNA by size.

(1) Why Other Options Are Incorrect:
- DNA sequencing is used to determine the exact sequence of nucleotides in a DNA molecule, not to separate DNA fragments by length.
- Site-directed mutagenesis is a technique used to introduce specific mutations at a particular site in the DNA, but it does not separate DNA fragments by size.
- Polymerase chain reaction (PCR) is a technique used to amplify specific DNA sequences, but it does not separate fragments based on size.

Conclusion: The correct technique for separating and analyzing DNA fragments of different lengths is gel electrophoresis.