Okazaki fragments are produced on the lagging strand during DNA replication. Which statement is true?

Okazaki fragments are produced on the lagging strand during DNA replication. Which statement is true?

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

Answer: (D)

Okazaki fragments arise because DNA polymerase can only synthesize DNA in the 5’ to 3’ direction. At the replication fork, the strand that runs 3’ to 5’ toward the fork can be copied continuously (the leading strand). The opposite strand runs 5’ to 3’ toward the fork, so synthesis must occur in short, discontinuous bursts away from the fork, creating Okazaki fragments. Each fragment begins with an RNA primer laid down by primase, and later the gaps are filled in and ligated to form a continuous strand. So the true statement is that Okazaki fragments are produced on the lagging strand, because only that strand requires/displays discontinuous synthesis. The leading strand is synthesized continuously, and neither strand would be correct to say lacks fragments or lacks these fragments entirely.

Okazaki fragments arise because DNA polymerase can only synthesize DNA in the 5’ to 3’ direction. At the replication fork, the strand that runs 3’ to 5’ toward the fork can be copied continuously (the leading strand). The opposite strand runs 5’ to 3’ toward the fork, so synthesis must occur in short, discontinuous bursts away from the fork, creating Okazaki fragments. Each fragment begins with an RNA primer laid down by primase, and later the gaps are filled in and ligated to form a continuous strand.

So the true statement is that Okazaki fragments are produced on the lagging strand, because only that strand requires/displays discontinuous synthesis. The leading strand is synthesized continuously, and neither strand would be correct to say lacks fragments or lacks these fragments entirely.