A student uses restriction enzymes to cut a DNA molecule into fragments. The digested DNA is loaded into the wells of an agarose gel and the gel is subjected to an electric current. Upon completion of the run, the gel is stained.
(A) they influence the rate of migration of the fragments
(B) they may cause some DNA molecules to replicate
(C) some DNA nucleotides may be lost due to chemical reactions with the gel
(D) some DNA molecules may sink to the bottom and not migrate
(E) some DNA molecules may cross-link
Answer: A
The type and density of the gel are important because
(A) they influence the rate of migration of the fragments
(B) they may cause some DNA molecules to replicate
(C) some DNA nucleotides may be lost due to chemical reactions with the gel
(D) some DNA molecules may sink to the bottom and not migrate
(E) some DNA molecules may cross-link
Answer: A