2. Either of the ends of a chromosome, which possess special properties, among them a polarity that prevents their reunion with any fragment after a chromosome has been broken: "The telemere is a repeating sequence of six 'letters' (amino acids) of DNA code: TTAGGG, which can be translated as THEEND because the mechanics of DNA replications are such that a portion of the telomere is lost with each cell division; a sequence that is repeated thousands of times in young cells."
3. The end of an arm of a chromosome.
"The ends of chromosomes are specialized structures that are involved in the replication and stability of DNA molecules."
"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 life-spans."
"Telomeres protect a cell's chromosomes from fusing with each other or rearranging (abnormalities that can lead to cancer) and so cells are normally destroyed when their telomeres are consumed."
"Most cancers are the result of immortal cells which have ways of evading this programmed destruction."
"Since telomeres are the protective caps on the ends of chromosomes that affect how quickly cells age, they have become known as combinations of DNA and protein that protect the ends of chromosomes and help them remain stable. As they become shorter, and as their structural integrity weakens, the cells age and die faster."
"In recent years, shorter telomeres have become associated with a broad range of aging-related diseases, including many forms of cancer, stroke, vascular dementia, cardiovascular disease, obesity, osteoporosis, and diabetes."
4. Etymology: the term telemere is derived from the Greek nouns telos (τἐλος), "end" + merοs (μέρος, "root"; μερεσ-) "part".