Why does a new DNA strand elongate only in the 5' to 3' direction during DNA replication?
A) DNA polymerase begins adding nucleotides at the 5' end of the template.
B) The polarity of the DNA molecule prevents addition of nucleotides at the 3' end.
C) Replication must progress toward the replication fork.
D) DNA polymerase can add nucleotides only to the free 3' end.

Question

Quizplus · Accepted Answer

DNA polymerase can only add nucleotides to the free 3' hydroxyl (-OH) group of the sugar molecule in the growing DNA strand. Therefore, elongation of the new DNA strand only occurs in the 5' to 3' direction, as new nucleotides are continuously added to the 3' end of the growing strand.

Why Does a New DNA Strand Elongate Only in the 5