Telomere shortening is a problem primarily in which types of cells?

• A. Germ cells
• B. Cancer cells
• C. Stem cells
• D. Somatic cells

Answer: (D)

Verified step by step guidance

1. Understand the role of telomeres: Telomeres are repetitive nucleotide sequences at the ends of chromosomes that protect them from deterioration or fusion with neighboring chromosomes.
2. Recognize the process of cell division: During cell division, DNA replication occurs, and telomeres shorten with each division because DNA polymerase cannot completely replicate the ends of linear chromosomes.
3. Identify the types of cells: Different types of cells include somatic cells (body cells), germ cells (reproductive cells), cancer cells, and stem cells.
4. Consider the function of telomerase: Telomerase is an enzyme that extends telomeres, counteracting shortening. It is active in germ cells, stem cells, and often in cancer cells, but not typically in somatic cells.
5. Conclude which cells are affected: Since telomerase is not active in most somatic cells, these cells experience telomere shortening over time, leading to aging and cell death, unlike germ, stem, and cancer cells where telomerase activity helps maintain telomere length.