What is the primary function of DNA polymerase during DNA replication?

• A. It synthesizes new DNA strands by adding nucleotides to a pre-existing strand.
• B. It unwinds the DNA double helix to initiate replication.
• C. It transcribes DNA into RNA.
• D. It repairs mismatched nucleotides in the DNA sequence.

Answer: (A)

Verified step by step guidance

1. Understand the role of DNA polymerase: DNA polymerase is an enzyme that plays a crucial role in DNA replication, which is the process of making a copy of DNA.
2. Identify the main function: The primary function of DNA polymerase is to synthesize new DNA strands. It does this by adding nucleotides, which are the building blocks of DNA, to a pre-existing strand.
3. Clarify the process: During DNA replication, DNA polymerase adds nucleotides to the 3' end of the newly forming DNA strand, using the original strand as a template.
4. Differentiate from other functions: DNA polymerase does not unwind the DNA double helix; this is the role of helicase. It also does not transcribe DNA into RNA; this is the function of RNA polymerase.
5. Consider repair functions: While DNA polymerase can have a role in repairing mismatched nucleotides, its primary function during replication is the synthesis of new DNA strands.