The lagging strand during DNA replication is characterized by what pattern?

The lagging strand during DNA replication is characterized by what pattern?

• A. Synthesized discontinuously in short fragments.
• B. Synthesized continuously.
• C. It is not replicated.
• D. It is identical to leading strand.

Answer: (A)

DNA polymerase can only add nucleotides in the 5' to 3' direction, and the two templates in the replication fork are antiparallel. As the fork opens, the strand that runs 5' to 3' toward the fork cannot be copied continuously in the same direction, so it is built in short segments that start near the fork and are extended away from it. These short pieces are called Okazaki fragments, each requiring a new RNA primer to begin synthesis, and later joined together by DNA ligase to form a continuous strand. This is why the lagging strand is described as synthesized discontinuously in short fragments, in contrast to the leading strand, which is synthesized continuously toward the fork.

DNA polymerase can only add nucleotides in the 5' to 3' direction, and the two templates in the replication fork are antiparallel. As the fork opens, the strand that runs 5' to 3' toward the fork cannot be copied continuously in the same direction, so it is built in short segments that start near the fork and are extended away from it. These short pieces are called Okazaki fragments, each requiring a new RNA primer to begin synthesis, and later joined together by DNA ligase to form a continuous strand. This is why the lagging strand is described as synthesized discontinuously in short fragments, in contrast to the leading strand, which is synthesized continuously toward the fork.