Why does replicative senescence occur in human somatic cells with each division, leading to increased susceptibility to age-related diseases?

💡 Explanation

Telomere shortening occurs because DNA polymerase cannot fully replicate the ends of linear chromosomes. Progressive telomere shortening activates DNA damage checkpoints, leading to cell cycle arrest and senescence; therefore, telomere length determines replicative capacity, rather than protein aggregation, DNA repair activation, or mitochondrial function.

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