What happens to telomeres with each cell division?

Telomeres are protective structures located at the ends of chromosomes that prevent the loss of important genetic information during cell division. Each time a cell divides, these telomeres shorten due to the inability of DNA polymerase to fully replicate the ends of linear chromosomes. As a result of this progressive shortening, the telomeres eventually reach a critical length that triggers cellular senescence, a state where the cell stops dividing, or apoptosis, which is programmed cell death. This shortening is a natural part of the cellular aging process and serves as a biological clock for the cell, reflecting its number of divisions and overall health.

The fact that telomeres shorten with each division provides a mechanism for limiting the lifespan of cells. This is crucial as it prevents the potential for uncontrolled growth that could lead to cancer. Therefore, the correct answer reflects the relationship between telomere length and cellular function, emphasizing the link to processes that control lifespan and cell proliferation.