The new continuous strand synthesized along the template in the 5' to 3' direction is called the Leading strand. Which option correctly names the other given strand?

• A. Lagging strand
• B. Okazaki fragment
• C. Complementary strand
• D. Leading strand

Answer: (D)

In DNA replication, strands are copied in opposite ways. One new strand is synthesized continuously in the 5' to 3' direction toward the replication fork—the leading strand. The other template runs the opposite way, so its new strand cannot be made in one piece; instead it is built in short segments away from the fork and later joined. That discontinuous, segment-by-segment synthesis defines the lagging strand. Okazaki fragments are the short pieces on this strand that get stitched together. The term complementary strand is too general, and the leading strand refers to the continuous one, not the other strand. So the correct name for the other strand is the lagging strand.