Answer: gaps left at the 5' end of the lagging strand.
Explanation:
Eukaryotic Chromosomes are known as the repetitive at the very ends of chromosomes, found in a wide range of Eukaryotic species. They protect the end chromosomes from deterioration or fusion with the neighboring chromosomes.
Telomeres provide a mechanism for their replication by semi conservative DNA replication (a replication in which two parental DNA strands would act as a template for new DNA strands to be synthesized) and length maintenance by Telomerase Enzymes. Telomerase Enzymes are used to extend shortened telomeres during its’ DNA replication.
DNA replication in Eukaryotic Telomeres doesn’t begins at the either end of the DNA strands but starts in the center, and considering that all known DNA Polymerase ( an enzyme that is essential for DNA replication) read the template strand in the 3’ to 5’ direction, one finds a leading strand and a lagging strand on the DNA molecule being replicated.
On the leading strand, DNA Polymerase make complementary DNA strand without any difficulty because it reads the template strand from 3’ to 5’.
On the other hand, there is a difficulty going in the other direction on the lagging strand.
WHY? This is “due to gaps left at the 5’ end of the lagging strand”. To overcome this difficulty, short sequences of RNA acting as Primers (a short single-stranded nucleic acid utilized by all living organisms in the initiation of DNA synthesis) attach to the lagging strand, a short distance ahead of where the initiation site was.
I hope this helps alot!
