In bacterial DNA replication, what is the primary function of DNA polymerase III?

• A. It synthesizes new DNA strands by adding deoxyribonucleotides to the $\prime$ end of a growing strand during replication.
• B. It unwinds the parental DNA double helix ahead of the replication fork.
• C. It seals nicks between adjacent Okazaki fragments by forming phosphodiester bonds.
• D. It removes RNA primers and replaces them with DNA nucleotides.

Answer: (A)

Verified step by step guidance

1. Understand the role of DNA polymerase III in bacterial DNA replication, which is primarily involved in synthesizing new DNA strands.
2. Recall that DNA polymerase III adds nucleotides to the 3' end of a growing DNA strand, extending it in the 5' to 3' direction.
3. Differentiate DNA polymerase III from other enzymes involved in replication, such as helicase (which unwinds DNA), DNA ligase (which seals nicks), and DNA polymerase I (which removes RNA primers and replaces them with DNA).
4. Recognize that DNA polymerase III's main function is to catalyze the polymerization of deoxyribonucleotides, ensuring accurate and efficient DNA synthesis.
5. Summarize that DNA polymerase III synthesizes new DNA strands by adding nucleotides to the 3' end of the growing strand during replication.