Telomeres prevent a loss of protein-encoding information during gene replication by providing a noncoding stretch of DNA whose loss will not affect the protein’s blueprint. This extra length of DNA allows the polymerase “train” to lose a piece of DNA without compromising the region containing the protein code. The length of the telomere extension determines how many times DNA can be copied before polymerase clipping cuts into the gene’s protein code. When frequent cell divisions deplete telomere extensions, subsequent copies of the DNA produce dysfunctional proteins.
