You cut a plasmid with a restriction enzyme that cuts it into three pieces - one fragment is 240 base pairs,one fragment is 600 base pairs,and one fragment is 1200 base pairs.You carry out electrophoresis of the digested sample.After ten minutes,which of the fragments,if any,will be closest to the top of the gel where the samples were inserted?
A)the 240 base pair fragment
B)the 600 base pair fragment
C)the 1200 base pair fragment
D)all three fragments will be equally near the top because of their identical sticky ends
E)it depends on the charge of the DNA fragment

Question

Quizplus · Accepted Answer

In gel electrophoresis, smaller DNA fragments move faster and farther through the gel than larger fragments. Therefore, the 1200 base pair fragment, being the largest, will be closest to the top where the samples were inserted, as it will move the slowest.

You Cut a Plasmid with a Restriction Enzyme That Cuts