Correct answer: Telomere
Chromosomes contain DNA packed together with histone proteins. Each chromosome has cap like structures at their ends called the telomeres. These telomeres are protective in function and they become short with each cell division. The cells eventually age as the telomere shortens after each cell division. Every time the chromosomes replicate, it would be shortened by 250 bases. Telomeres prevent the loss of important segments of the DNA as they act as a cap at the ends of the chromosomes. At the end of each division, this protective cap is lost,