Final answer:
DNA replication is semi-conservative and involves a continuous leading strand and a discontinuous lagging strand due to the directional limitation.
Step-by-step explanation:
DNA replication is a critical process that involves the production of two identical copies of a DNA molecule. This replication is semi-conservative, meaning that each new DNA molecule consists of one old (parental) strand and one new strand. DNA replication is said to be bidirectional because it proceeds in two directions from a starting point.
The reason for discontinuous replication on the lagging strand is due to the anti-parallel nature of DNA strands. Each DNA strand has a 5' to 3' end, and DNA polymerase, the enzyme responsible for adding nucleotides, can only add new nucleotides to the 3' end of a strand.
The lagging strand is synthesized in a discontinuous manner because DNA polymerase must repeatedly start and stop, moving away from the replication fork to open new sections of DNA for replication. This is essential due to the need for DNA polymerase to access the DNA in a 5' to 3' direction.