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Multiple Choice
How do short strands of DNA move through a gel during electrophoresis compared to long strands?
A
Short strands do not move through the gel.
B
Short strands move at the same speed as long strands.
C
Short strands move faster than long strands.
D
Short strands move slower than long strands.
Verified step by step guidance
1
Understand the principle of gel electrophoresis: It is a technique used to separate DNA fragments based on their size. DNA molecules are negatively charged due to their phosphate backbone, and when an electric field is applied, they move towards the positive electrode.
Consider the structure of the gel: The gel is typically made of agarose or polyacrylamide, which forms a matrix with pores. The size of these pores affects how DNA strands move through the gel.
Analyze the movement of DNA strands: Short strands of DNA can navigate through the pores of the gel more easily than long strands. This is because shorter strands encounter less resistance and can move more quickly through the matrix.
Compare the speed of movement: Since short strands face less resistance, they move faster through the gel compared to long strands, which are slowed down by the gel matrix.
Conclude the comparison: Therefore, in gel electrophoresis, short strands of DNA move faster than long strands due to their ability to pass through the gel matrix with less hindrance.