A Sample of the Same DNA Is Placed into Each

Multiple Choice

A sample of the same DNA is placed into each of two test tubes.Each tube is treated with a restriction enzyme,and the resulting fragments are separated by gel electrophoresis,producing the gel shown in the following figure.Which of the following explains why the pattern of DNA fragments differs in these two samples?

A) Different restriction enzymes must have been used in the different tubes.
B) One tube was heated, but the other tube was not.
C) Ligase was added to one of the tubes but not the other.
D) The restriction enzyme added to the tubes cut DNA at more than one sequence.