Question

In gel electrophoresis, DNA fragments are separated mainly on the basis of:

• A. Shape
• B. Density
• C. Charge only
• D. Size

Hint:

Remember: \[ \text{Smaller DNA fragment} \rightarrow \text{Moves faster in gel} \] \[ \text{Larger DNA fragment} \rightarrow \text{Moves slower} \]

Answer 1

The Correct Option is D

Concept: Gel electrophoresis is a technique used to separate DNA fragments. DNA molecules are negatively charged due to phosphate groups and move towards the positive electrode.

Step 1: Understand movement of DNA in gel. When electric current is passed:

• DNA fragments move through agarose gel
• Smaller fragments move faster
• Larger fragments move slower

Step 2: Identify basis of separation. Since smaller fragments travel more distance in the same time: \[ \text{DNA fragments are separated based on size} \] Therefore, the correct answer is: \[ \boxed{\text{Size}} \]