A
telomere is a region of repetitive
nucleotide sequences at each end of a
chromosome, which protects the end of the chromosome from deterioration or from fusion with neighboring chromosomes. Its name is derived from the Greek nouns telos (
τέλος) 'end' and merοs (
μέρος, root:
μερ-) 'part.' For
vertebrates, the sequence of nucleotides in telomeres is
TTAGGG. This sequence of TTAGGG is repeated approximately 2,500 times in humans.