Final answer:
DNA polymerase adds nucleotides continuously to the leading strand during DNA replication because it is complementary to the parental 3' to 5' strand.
Step-by-step explanation:
In DNA replication, DNA polymerase adds nucleotides in a continuous manner to the leading strand. The leading strand is synthesized continuously because it is complementary to the parental 3' to 5' DNA strand, and since DNA polymerase can only add nucleotides in the 5' to 3' direction, it naturally extends towards the replication fork. This contrasts with the lagging strand, where DNA is synthesized in short segments, known as Okazaki fragments, which are later joined together.