Question

At the end of the DNA replication process, telomerase activity is higher

Select one:

a. At the 3’ end of the lagging strand

b. At the 3’ end of both strands

c. At the 5’ end of the leading strand

d. At the 5’ end of the lagging strand

e. At the 3’ end of the leading strand

Answer 1

Answer: a. At the 3’ end of the lagging strand

Explanation:

At each cell division, the telomeres shorten because of the incomplete replication of the linear DNA molecules by the conventional DNA polymerases. This is called the end DNA replication problem. Some cells have the ability to reverse telomere shortening by expressing telomerase, an enzyme that extends the telomeres of chromosomes.

Telomerase adds complementary RNA bases to the 3′ end of the DNA strand. Once the 3′ end of the lagging strand template is sufficiently elongated, DNA polymerase adds the complementary nucleotides to the ends of the chromosomes. Thus the ends of the chromosomes are replicated and produce double-stranded DNA.

So the answer is “a. At the 3’ end of the lagging strand”.