On which strand are Okazaki fragments formed?

On which strand are Okazaki fragments formed?

• A. Leading strand
• B. Lagging strand
• C. Both strands
• D. Neither

Answer: (C)

Okazaki fragments form on the lagging strand. DNA polymerase can only add nucleotides in the 5' to 3' direction, so the two strands are replicated differently because they are antiparallel. The leading strand runs 3' to 5' toward the replication fork, allowing continuous synthesis in the same direction as fork movement. The lagging strand runs 5' to 3' toward the fork, so synthesis must occur in short, discontinuous segments that are initiated by RNA primers. These short segments are the Okazaki fragments, which are later joined by DNA ligase. So, Okazaki fragments are characteristic of the lagging strand, not the leading strand.

Okazaki fragments form on the lagging strand. DNA polymerase can only add nucleotides in the 5' to 3' direction, so the two strands are replicated differently because they are antiparallel. The leading strand runs 3' to 5' toward the replication fork, allowing continuous synthesis in the same direction as fork movement. The lagging strand runs 5' to 3' toward the fork, so synthesis must occur in short, discontinuous segments that are initiated by RNA primers. These short segments are the Okazaki fragments, which are later joined by DNA ligase. So, Okazaki fragments are characteristic of the lagging strand, not the leading strand.