Which term describes the aging process as it affects molecules and cells and is the focus of many aging theories?

• A. Wear and tear
• B. Genetic clock
• C. Cellular aging
• D. Demographic shift

Answer: (C)

Aging at the smallest biological units—molecules and cells—is captured by cellular aging. This term describes how cells gradually lose function due to accumulated damage, changes in gene expression, and processes like telomere shortening that limit replication. Because it focuses on the changes occurring inside cells and at the molecular level, cellular aging is the central focus of many aging theories, which seek to explain how such cellular and molecular changes drive the overall aging process. The other terms describe different ideas: wear and tear is a broad, less precise notion of damage from use; a demographic shift refers to population-level aging; and a genetic clock is more about timing mechanisms than the cellular aging process itself.