Telomere maintenance by telomerase is particularly important in which cell types?

• A. Mature neurons
• B. Mature red blood cells
• C. Germ cells and stem cells
• D. Muscle cells

Answer: (C)

Telomeres shorten with each cell division, acting as a mitotic clock, and telomerase adds repeats to extend them, allowing more divisions without losing essential DNA. Cells that must divide throughout life or pass genetic material to offspring rely on telomerase to maintain telomere length. Germ cells and stem cells fit this need: germ cells must preserve genome integrity across generations, and stem cells continuously renew tissues, requiring sustained telomere maintenance to keep a healthy, proliferative pool. In contrast, mature neurons, mature red blood cells, and many muscle cells are largely non-dividing, so preserving telomere length via telomerase is less critical for their function. Thus, telomerase maintenance is particularly important in germ cells and stem cells.