What is the primary function of telomeres in eukaryotic chromosomes?

Telomeres serve a crucial role in maintaining the integrity of eukaryotic chromosomes by preventing chromosome shortening. These structures are repetitive nucleotide sequences located at the ends of linear chromosomes that protect the ends from degradation and from being recognized as damaged DNA. During cell division, DNA replication does not completely replicate the ends of linear chromosomes, which can lead to progressive shortening each time a cell divides. Telomeres counteract this potential loss of vital genetic information by providing a buffer that allows the cell to divide without losing essential sequences that code for genes.

When telomeres become critically short, cells can enter a state of senescence or undergo programmed cell death, which is a protective mechanism against the propagation of damaged DNA. Consequently, the function of telomeres is vital not only for chromosome stability but also for the cellular lifespan and overall health of an organism.