A telomere [tel-uh-meer] is a region of repetitive DNA at the
end of a chromosome, which protects the end of the chromosome
from deterioration. The telomere regions deter the degradation
of genes near the ends of chromosomes by allowing for the
shortening of chromosome ends, which necessarily occurs during
chromosome replication. During cell division, enzymes that
duplicate DNA cannot continue their duplication all the way to
the end of the chromosome. If cells divided without telomeres,
they would lose the ends of their chromosomes, and the necessary
information they contain. The telomeres are disposable buffers
blocking the ends of the chromosomes and are consumed during
cell division and replenished by an enzyme, the telomerase
reverse transcriptase. The telomere shortening mechanism
normally limits cells to a fixed number of divisions, and animal
studies suggest that this is responsible for aging on the
cellular level and sets a limit on lifespans. Telomeres protect
a cell’s chromosomes from fusing with e