Which term best describes the strand that is synthesized continuously toward the replication fork?

Which term best describes the strand that is synthesized continuously toward the replication fork?

• A. Leading strand
• B. Lagging strand
• C. Okazaki fragments
• D. Template strand

Answer: (A)

In DNA replication, synthesis always proceeds in the 5' to 3' direction. The strand that runs in the 3' to 5' direction toward the replication fork can be copied continuously as the fork opens, so the daughter strand is made in one smooth piece—the leading strand. The other parental strand runs 5' to 3' toward the fork and must be copied in short segments that are later joined, which is the lagging strand with Okazaki fragments. The term template strand refers to whichever parental strand is being used as the template, not specifically the continuous vs. discontinuous nature of synthesis. So, the strand synthesized continuously toward the fork is the leading strand.

In DNA replication, synthesis always proceeds in the 5' to 3' direction. The strand that runs in the 3' to 5' direction toward the replication fork can be copied continuously as the fork opens, so the daughter strand is made in one smooth piece—the leading strand. The other parental strand runs 5' to 3' toward the fork and must be copied in short segments that are later joined, which is the lagging strand with Okazaki fragments. The term template strand refers to whichever parental strand is being used as the template, not specifically the continuous vs. discontinuous nature of synthesis. So, the strand synthesized continuously toward the fork is the leading strand.