Answer: Discontinuously, away from the replication fork, in short fragments.
- A Continuously in the same direction as the replication fork movement
- B Discontinuously, away from the replication fork, in short fragments
- C Without any RNA primer
- D In the 3 prime to 5 prime direction by DNA polymerase
Correct answer: B. Discontinuously, away from the replication fork, in short fragments
Explanation: Because DNA polymerase synthesises only 5 prime to 3 prime, the lagging strand is made discontinuously in short Okazaki fragments moving away from the fork.
Helicase unwinds the double helix at the replication fork; one new strand (leading) is synthesised continuously toward the fork, while the other (lagging) must be made in short, separate Okazaki fragments because DNA polymerase only adds nucleotides 5'→3'.
Concept context
DNA structure, replication, transcription, translation, the genetic code, and gene regulation (lac operon). The single most important chapter for NEET molecular biology.