They say the lengths of tiny pieces of DNA called telomeres indicate whether a young creature is likely to live long into old age. ... Everything that is made up of living cells contains chromosomes: the genetic code that makes us what we are. At the ends of each chromosome lie the telomeres. They have been likened to the caps on the ends of shoelaces - they stop things from unravelling. Over time they wear down - and when they do, the DNA they protect is compromised and the cell can malfunction or die.
telomere longevity health chromosome age