In gel electrophoresis, how do short strands of DNA move compared to long strands?

• A. Long strands of DNA move faster and travel farther through the gel than short strands.
• B. Short and long strands of DNA move at the same rate through the gel.
• C. Short strands of DNA move slower and travel a shorter distance through the gel than long strands.
• D. Short strands of DNA move faster and travel farther through the gel than long strands.

Answer: (D)

Verified step by step guidance

1. Understand the principle of gel electrophoresis: DNA fragments are separated based on their size because the gel acts like a molecular sieve.
2. Recall that DNA molecules are negatively charged and move towards the positive electrode when an electric current is applied.
3. Recognize that shorter DNA strands experience less resistance moving through the gel matrix compared to longer strands.
4. Conclude that shorter DNA fragments migrate faster and travel farther through the gel than longer DNA fragments during electrophoresis.
5. Therefore, the correct understanding is that short strands of DNA move faster and travel farther through the gel than long strands.