Okazaki fragments refer to short DNA segments synthesized on which strand?

• A. Short fragments of DNA on the leading strand.
• B. Long continuous strands on the lagging strand.
• C. Short fragments of DNA synthesized on the lagging strand.
• D. RNA transcripts.

Answer: (C)

Okazaki fragments are short DNA segments synthesized on the lagging strand during DNA replication. DNA polymerase can only add nucleotides in the 5' to 3' direction, so the template strand that runs 3' to 5' away from the replication fork is copied in short bursts. Primase lays down an RNA primer for each burst, and DNA polymerase extends from the primer to form a short DNA fragment. After synthesis, the RNA primers are removed and replaced with DNA, and the fragments are joined by DNA ligase to create a continuous lagging strand. The leading strand, in contrast, is synthesized continuously toward the fork. RNA transcripts are not involved in this process, as Okazaki fragments are DNA, not RNA.