During DNA replication, the leading strand is synthesized in the 5' to 3' direction. The strand that runs away from the replication fork is synthesized in Fragments because DNA polymerase cannot synthesize in the 3’ to 5’ direction.
Explanation:
A replication fork has one strand called the leading strand, it is synthesized continuously from a single primer on the leading strand template and grows in 5'-3' direction.
The leading strand grows in the same direction in which the replication fork grows.
The other strand is the lagging strand that is unveiled by the growing replication fork. It proceeds in the direction opposite to the movement of growing replication fork.
The lagging strand is synthesized discontinuously because the DNA polymerase can add nucleotides only to the 3' end of a primer.
These short pieces of synthesized DNA are okazaki fragments.Okazaki fragments are joined later by ligase.
