Which of the following statements about DNA replication is correct? Fragments are formed on the A leading strand and are joined by DNA polymerase B lagging strand and are joined by ligase C lagging strand and are joined by DNA polymerase D leading strand and are joined by ligase. - Scottish Highers Human Biology - Question 2. - 2023

During DNA replication, the replication process occurs in two directions due to the antiparallel nature of the DNA strands. On the leading strand, DNA polymerase synthesizes DNA continuously in the direction of the replication fork. Conversely, the lagging strand is synthesized discontinuously in short segments known as Okazaki fragments.

These Okazaki fragments are initially created by DNA polymerase, but they are not joined together immediately. Instead, a different enzyme, DNA ligase, is required to connect these fragments, sealing the nicks in the sugar-phosphate backbone, thus forming a continuous strand of DNA.

Therefore, the correct answer is:

B: lagging strand and are joined by ligase.