In the overview of DNA replication, what is the primary role of DNA polymerase?

• A. It synthesizes new DNA strands by adding complementary nucleotides to the growing strand in the $5\prime \to 3\prime$ direction.
• B. It joins Okazaki fragments together on the lagging strand.
• C. It removes RNA primers and replaces them with DNA.
• D. It unwinds the DNA double helix ahead of the replication fork.

Answer: (A)

Verified step by step guidance

1. Understand that DNA polymerase is an enzyme involved in DNA replication, responsible for synthesizing new DNA strands.
2. Recall that DNA polymerase adds nucleotides complementary to the template strand, ensuring accurate base pairing (A with T, and G with C).
3. Note that DNA polymerase can only add nucleotides in the 5\' to 3\' direction, meaning it extends the new strand by adding nucleotides to the 3\' end.
4. Distinguish the role of DNA polymerase from other enzymes: for example, DNA ligase joins Okazaki fragments, and helicase unwinds the DNA helix.
5. Conclude that the primary role of DNA polymerase is to synthesize new DNA strands by adding complementary nucleotides in the 5\' to 3\' direction.