What are the 2 cells in the human body that don't age?

• A. Red blood cells and neurons
• B. Liver cells and skin cells
• C. Bone cells and muscle cells
• D. Sperm and Cancer cells

Answer: (D)

A key idea here is how cell aging works and how some cells avoid the usual limit on divisions. Most body cells shorten their chromosome ends (telomeres) as they divide, which eventually leads to senescence or death. But some cell types have ways to keep those telomeres long and continue dividing.

Germ cells, the precursors to sperm, maintain telomere length through telomerase activity. This keeps their genetic ends stable across many generations, so the germline can be passed on without the usual aging limit that somatic cells hit. Cancer cells often reactivate telomerase or use other mechanisms to preserve telomeres, giving them the ability to divide indefinitely in many contexts. Because of these features, these two cell types are described as not aging in the same way as most other body cells.

Keep in mind that real biology is more nuanced: sperm lose function with time, and cancer cells can accumulate changes that lead to other problems. But the idea tests the concept that telomere maintenance allows certain cells to bypass the typical replicative aging seen in other tissues.