Question

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.

Answer 1

A new DNA strand elongate only in the 5' to 3' direction during DNA replication because the  "polarity of the DNA molecule prevents addition of nucleotides at the 3' end" .

DNA replication occurs in the 5' to 3' direction. DNA polymerase can only add nucleotides to the 3' OH group of the growing DNA strand, this is why DNA replication occurs only in the 5' to 3' direction.

DNA polymerase can only add to the 3' end, so the 5' end of the primer remains unaltered. Consequently, synthesis proceeds immediately only along the so-called leading strand.

Hence, the correct answer will be option (B)

To learn more about DNA strand here

brainly.com/question/13542701

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