What is the role of the sliding clamp in replication?

• A. It increases processivity of DNA polymerase.
• B. It unwinds DNA ahead of the fork.
• C. It ligates Okazaki fragments.
• D. It synthesizes RNA primers.

Answer: (A)

The sliding clamp increases processivity of DNA polymerase. It forms a ring that encircles the DNA and tethers the polymerase to the template, so the enzyme can synthesize many nucleotides without falling off. This tight association speeds up replication on both the leading and lagging strands. The other functions listed belong to different proteins: helicase unwinds DNA, ligase joins Okazaki fragments, and primase synthesizes RNA primers.