Final answer:
In eukaryotic DNA replication, DNA polymerase delta is responsible for elongating the lagging strand, while DNA polymerase epsilon elongates the leading strand. These polymerases synthesize DNA in opposite directions due to the directionality of DNA polymerases, and a special enzyme telomerase extends telomeres to protect chromosome ends.
Step-by-step explanation:
In eukaryotic replication, DNA polymerase delta elongates the lagging strand, and DNA polymerase epsilon elongates the leading strand. Both strands are synthesized simultaneously at the replication fork, but they are synthesized in different ways due to the inherent directionality of DNA polymerases, which can only add nucleotides to the free 3' end of a DNA strand. This results in continuous synthesis of the leading strand and discontinuous synthesis of the lagging strand in short segments known as Okazaki fragments.
The leading strand synthesis is straightforward and continuous, with polymerase epsilon working towards the replication fork. The lagging strand, however, requires short RNA primers made by primase, upon which polymerase delta can initiate synthesis. After reaching the next RNA primer, polymerase delta, with the help of additional enzymes like RNase H and DNA ligase, replaces the RNA primers with DNA and seals the gaps between Okazaki fragments, respectively, forming a continuous DNA strand.
Telomerase plays a unique role at the ends of linear chromosomes, using an inbuilt RNA template to extend the telomeres and prevent loss of genetic material over successive rounds of cell division.