Final answer:
The leading strand of DNA is synthesized continuously in the 5' to 3' direction, complementary to the 3' to 5' parental DNA strand, during DNA replication.
Step-by-step explanation:
The leading strand of DNA is synthesized continuously during DNA replication. This process occurs because DNA polymerase can only add nucleotides in a 5' to 3' direction, which is complementary to the 3' to 5' parental DNA strand. As replication progresses, this strand is synthesized smoothly in the same direction as the replication fork. In contrast, the lagging strand is synthesized in short, discontinuous segments called Okazaki fragments because it is complementary to the 5' to 3' parental DNA strand and extends away from the replication fork.