Which of the following statements reflects the process by which of the telomeric ends of chromosomes are replicated?
A) a unique DNA molecule serves as the primer for synthesis
B) a unique RNA molecule serves as the template for synthesis
C) short template-independent blocks of DNA are ligated to the ends using a 5′ → 5′ bond
D) telomeres are replicated as short tandem repeated stretches of ribonucleotides instead of deoxyribonucleotides
E) telomeres are replicated in a temple-independent process

Question

Quizplus · Accepted Answer

Telomerase, an enzyme with an RNA component, uses its RNA as a template to extend the telomeres, allowing DNA polymerase to complete replication.  The telomeric end on the lagging strand of a replicating eukaryotic chromosome is synthesized by an enzymatic activity termed telomerase. Telomerase is complex composed of several proteins, an RNA with sequence complimentary to the telomeric repeats, and a reverse transcriptase activity that extends the 3′-end of the lagging strands using the telomerase RNA as the template. The reverse transcriptase activity of telomerase is encoded by the TERT gene (telomerase reverse transcriptase) and the RNA component is encoded by the TERC gene (telomerase RNA component). The TERC RNA contains a repeating hexanucleotide sequence, 3′-AAUCCC-5′, that spans between 3 and 20 kilobases. This sequence in the TERC RNA forms a duplex with the lagging DNA strand at the ends of the chromosomes. The 3′-end of the lagging strand then serves as the primer for the reverse transcriptase activity (TERT) which extends the 3′-end of the chromosome using the TERC RNA as a template.

Which of the Following Statements Reflects the Process by Which