Telomerase activity is typically found in which cells?

• A. Germ cells, stem cells, and some cancer cells.
• B. Mature somatic cells only.
• C. All differentiated cells.
• D. Bacteria.

Answer: (A)

Telomerase keeps chromosome ends from shortening during cell division, so it is active in cells that need to divide many times. Germ cells and stem cells maintain telomere length to preserve genetic information across generations and throughout growth. Some cancer cells reactivate telomerase, which helps them divide indefinitely. In contrast, mature somatic cells usually have little or no telomerase, so their telomeres shorten with each division and they have a limited lifespan. Bacteria generally don’t rely on telomeres or telomerase because their chromosomes are typically circular.