Answer:
B. the gaps left by primer removal of lagging strands to be repaired by telomerase.
Step-by-step explanation:
Telomeres are usually known as the repetitive regions at the very ends of chromosomes. They are numerously found in eukaryotic species(eukaryotic chromosomes) ranging from humans to unicelluar protozoans (protists).
Unlike bacterial chromosomes,eukaryotic chromosomes are linear (rod-shaped), i.e they have ends.
So, when DNA is being copied, one of the two new strands of DNA at a replication fork is made continuously and is called the leading strand. The other strand is produced in many small pieces called Okazaki fragments, each of which begins with its own RNA primer, and is known as the lagging strand.
In most cases, the primers of the Okazaki fragments can be easily replaced with DNA and the fragments connected to form an unbroken strand.
Telomerase is an RNA-dependent DNA polymerase enzyme, i.e an enzyme that can make DNA using RNA as a template. Their function is to extends the telomeres of chromosomes.
So when telomerase binds to a special RNA molecule that contains a sequence complementary to the telomeric repeat, It adds nucleotide to the overhanging strand of the telomere DNA using this complementary RNA as a template.
Therefore, The telomeres at the ends of linear chromosomes allow the gaps left by primer removal of lagging strands to be repaired by telomerase.