RNA primers during prokaryotic replication are removed by which mechanism?

RNA primers during prokaryotic replication are removed by which mechanism?

• A. RNA primers are removed by RNA polymerase
• B. RNA primers are removed by DNA polymerase III
• C. RNA primers are removed by DNA polymerase I via 5' to 3' exonuclease activity
• D. RNA primers remain in DNA after replication

Answer: (C)

RNA primers are removed during prokaryotic DNA replication by DNA polymerase I, which has a 5' to 3' exonuclease activity that digests the RNA primers. As it removes the RNA, its 5' to 3' polymerase activity fills the resulting gaps with DNA. After this replacement, DNA ligase seals the remaining nick to produce a continuous DNA strand. RNA polymerase is responsible for primer synthesis, not removal, and DNA polymerase III lacks the 5' to 3' exonuclease needed to remove RNA primers. The primers do not stay in the final DNA sequence.

RNA primers are removed during prokaryotic DNA replication by DNA polymerase I, which has a 5' to 3' exonuclease activity that digests the RNA primers. As it removes the RNA, its 5' to 3' polymerase activity fills the resulting gaps with DNA. After this replacement, DNA ligase seals the remaining nick to produce a continuous DNA strand. RNA polymerase is responsible for primer synthesis, not removal, and DNA polymerase III lacks the 5' to 3' exonuclease needed to remove RNA primers. The primers do not stay in the final DNA sequence.