試題詳解

55. What is the basis for the difference in the synthesis of the leading and lagging strands of DNA molecules?
(A) The origins of replication occur only at the 5’ end of the molecule.
(B) Helicases and single-strand binding proteins work at the 5’ end.
(C) DNA polymerase can join new nucleotides only to the 3’ end of the growing strand.
(D) DNA ligase works only in the 3’ →5’ direction.
(E) Polymerase can only work on one strand at a time.