Final answer:
Researchers investigating DNA have found that the length of telomeres for a species may determine certain aspects such as rapid aging. Shorter telomeres can inhibit cell division, which leads to more rapid aging.
Step-by-step explanation:
Telomeres are regions of repetitive DNA sequences at the ends of chromosomes, and their length can determine certain aspects of a species. Researchers have found that shorter telomeres can inhibit or block cell division, leading to more rapid aging. For example, a study compared telomere lengths in white blood cells of mothers of chronically ill children to those of mothers of healthy children, and found that the longer a mother had spent caring for her ill child, the shorter her telomeres. Higher levels of perceived stress were also negatively correlated with telomere size.