Question

During DNA replication, the addition of nucleotides on the lagging strand occurs.

• A. Towards the replicating fork
• B. At a faster rate than leading occurs
• C. Continuously
• D. Discontinuously

Answer 1

Answer: (D)

• As DNA polymerase replicates DNA only in 5' to 3' direction, replication in the strand with 3'-5' polarity is continuous.
• While replication in 5'-3' strand, is discontinues. The lagging strand is synthesized in short, separated segments. On the lagging strand template, a primase "reads" the template DNA and initiates synthesis of a short complementary RNA primer. A DNA polymerase extends the primed segments, forming Okazaki fragments. The RNA primers are then removed and replaced with DNA, and the fragments of DNA are joined together by DNA ligase.
• So, the correct option is 'Discontinuously'.