What enzyme is required to join gaps between fragments on the lagging strand?

DNA Ligase is the enzyme essential for joining gaps between fragments on the lagging strand during DNA replication. The lagging strand is synthesized discontinuously in short segments called Okazaki fragments, which are created due to the antiparallel nature of the DNA strands. After these fragments are synthesized, there are small gaps that remain between them where RNA primers were initially placed. DNA Ligase acts to seal these nicks, creating a continuous sugar-phosphate backbone in the newly formed DNA strand.

The other enzymes play distinct roles during DNA replication. Helicase is responsible for unwinding the DNA double helix, allowing the replication machinery access to the template strands. DNA Polymerase synthesizes new DNA strands by adding nucleotides complementary to the template strand. Primase synthesizes short RNA primers necessary for DNA Polymerase to start adding nucleotides. Each of these enzymes is crucial for different steps in the replication process, but it is DNA Ligase that specifically addresses the gaps left between the Okazaki fragments on the lagging strand.