During DNA replication, which strand is synthesized continuously?

During DNA replication, the leading strand is synthesized continuously towards the replication fork. This is due to the direction in which DNA polymerase works. DNA polymerase can only add nucleotides to the 3' end of a growing DNA strand, which means that new nucleotides are added in a 5' to 3' direction. As the DNA unwinds, the leading strand runs in the same direction as the movement of the replication fork, allowing DNA polymerase to add nucleotides continuously without interruption.

In contrast, the other strand, known as the lagging strand, is synthesized in short fragments called Okazaki fragments. This occurs because the lagging strand runs in the opposite direction to the fork's movement, necessitating a start-and-stop synthesis process where short sections of new DNA are pieced together.

This understanding of the leading and lagging strands is fundamental in grasping how DNA replication ensures complete and accurate copying of genetic information.