Telomeres Shortening - Contributors and Implications

Telomeres are bits of “non-coding DNA” on the end of chromosomes that protect your real DNA every time a cell divides. What happens is that, on account of how cells divide, the final bit of a chromosome can't be copied 100% - a bit of bit will get lower off. It was thought that, as cell divide, there's telomere shortening each time, till, they're gone. At that time, the “real DNA” can't be copied anymore and the cell simply ages and not replicates.