DNA replication in eukaryotes occurs semi-conservatively, with each parental DNA strand serving as a template to create new daughter strands. It begins at origins of replication and proceeds bidirectionally. Enzymes such as helicase unwind the DNA double helix, while DNA polymerase adds complementary nucleotides to the leading and lagging strands. The lagging strand is synthesized discontinuously in short segments called Okazaki fragments. Telomeres protect chromosome ends from degradation during replication, and the telomerase enzyme maintains telomere length.