What function do telomeres serve in chromosomes?

Telomeres play a crucial role in maintaining chromosome integrity and stability. They are repetitive nucleotide sequences located at the ends of linear chromosomes, acting as protective caps that prevent the chromosomes from deteriorating or fusing with each other. Each time a cell divides, a small portion of the telomere is lost, which protects the vital coding regions of the DNA from being shortened during replication. This protective function ensures that the essential genetic information remains intact, thereby contributing to cellular function and longevity.

As cells continue to divide, the telomeres gradually shorten, which eventually leads to cellular senescence or apoptosis when they reach a critically short length. This mechanism is an important aspect of cellular aging and has significant implications for cancer biology, as many cancer cells can bypass this limit, leading to uncontrolled proliferation. Hence, the function of telomeres is fundamentally about safeguarding the internal regions of chromosomes and ensuring the maintenance of genomic integrity.