USA Biology Olympiad (USABO) Practice Exam

What is the primary function of telomerase in cellular biology?

1. Stimulating cell division

2. Repairing DNA damage

3. Maintaining telomere length

4. Initiating apoptosis

The correct answer is: Maintaining telomere length

The primary function of telomerase in cellular biology is to maintain telomere length. Telomeres are repetitive nucleotide sequences at the ends of chromosomes that protect them from deterioration or fusion with neighboring chromosomes. As cells divide, telomeres shorten, which can eventually lead to cellular senescence or apoptosis when they become too short. Telomerase is an enzyme that adds specific nucleotide sequences to the ends of telomeres, effectively counteracting this shortening process. It is most active in stem cells, germ cells, and certain types of cancer cells, allowing these cells to divide indefinitely by maintaining their telomeres. While stimulating cell division, repairing DNA damage, and initiating apoptosis are important processes in cellular biology, they are not the primary function of telomerase. Instead, it is the role of telomerase in preserving the integrity of telomeres that is critical for the continued proliferation of those cells that require a high capacity for division.