Final answer:
The statement on the high AT content of telomeres is false; they actually contain a sequence rich in GC pairs. Telomeres protect chromosome ends, and the enzyme telomerase, active in germ and stem cells but not in somatic cells, adds repetitive DNA to telomeres, affecting aging and cell death.
Step-by-step explanation:
Telomeres actually have a high content of guanine (G) and cytosine (C) base pairs, which are known for three hydrogen bonds, hence creating stronger strand interactions than adenine (A) and thymine (T), which only form two hydrogen bonds.
Telomeres are repetitive nucleotide sequences at the ends of chromosomes that protect genetic data during cell division. Over time, due to the end replication problem, telomeres shorten. The enzyme telomerase helps to maintain the length of telomeres by adding repetitive DNA sequences to the ends of chromosomes, using an RNA template that is part of the enzyme.
In humans, telomerase activity is generally high in germ cells and adult stem cells, but is downregulated in somatic cells. This downregulation is associated with aging and cell death, or apoptosis. However, telomerase can become reactivated in cancer cells, contributing to their unchecked growth and division by preventing telomere shortening.