telomere

American  

[tel-uh-meer, tee-luh‑] / ˈtɛl əˌmɪər, ˈti lə‑ /

noun

1. the segment of DNA that occurs at the ends of chromosomes.

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telomere British  

/ ˈtɛləˌmɪə /

noun

1. genetics either of the ends of a chromosome

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telomere Scientific  

/ tĕl′ə-mîr′,tē′lə- /

1. Either of the sections of DNA occurring at the extreme ends of each chromosome in a eukaryotic cell. Telomeres consist of highly repetitive sequences of DNA that do not code for proteins, but function as caps to keep chromosomes from fusing together. The length of the telomere influences the stability of genetic information just interior of the telomere, since the nucleotide sequences at the ends of a chromosome are not copied by DNA polymerase. Successive copying can thus shorten telomeres, sometimes to the point that functional genes near the telomeres are lost, and this may play a role in cellular senescence and age-related diseases. In germ cells, stem cells, and some cancer cells, shortened telomeres can be extended by the enzyme telomerase, thus keeping both the telomeres and the genes near them functioning. Most somatic cells do not express telomerase, and the shortening of telomeres during each round of cell division may be part of the natural aging of cells.

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telomere Cultural  

1. The long end sequences of a DNA strand occurring at the tip of the chromosomes; a type of repetitive DNA that usually consists of one hundred to fifteen hundred copies of a single DNA sequence.

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Discover More

During DNA replication, small parts of the telomere are lost with each cycle. Scientists think that this loss may be related to the aging process.

Etymology

Origin of telomere

First recorded in 1935–40

Example Sentences

In each of these systems, cells can become senescent due to factors such as oxidative stress, mitochondrial dysfunction, DNA damage, chronic inflammation, metabolic stress, telomere shortening, ultraviolet radiation, and environmental pollution.

From Science Daily • May 22, 2026

"Restoring a more youthful microbiome can reverse several core features of aging at both the molecular and functional level, including inflammation, fibrosis, mitochondrial decline, telomere attrition, and DNA damage," Dr. Li said.

From Science Daily • May 9, 2026

A key focus was how this protein interacts with stem cells affected by telomere dysfunction.

From Science Daily • Feb. 12, 2026

The second measured telomere length, which refers to protective structures at the ends of chromosomes.

From Science Daily • Dec. 12, 2025

They also knew that there was a string of DNA at the end of each chromosome called a telomere, which shortened a tiny bit each time a cell divided, like time ticking off a clock.

From "The Immortal Life of Henrietta Lacks" by Rebecca Skloot