### body part | extremity | end:

Telomere
* act as markers indicating the cell's lifetime
  - like DNA caps at the ends of chromosomes
* also play a role in cancer.
* are DNA strands at each end of a cell's DNA that become shorter with each cell division
  - a specialized structure at the ends of each chromosomal arm
  - apparently a way of counting and controlling how many times a cell can reproduce
  - composed of a repeated six base sequence that are lost during cell division
  - destroyed during cell division, and are remade by the enzyme telomerase
  - essential for both chromosome stability and for length maintenance
  - found at the termini of chromosomes
  - like protective tips at the end of chromosomes, which carry genes inside every cell
* are necessary to preserve the integrity of the genetic material through the cell cycle
  - protect chromosomes from degradation and fusion
* are pieces of DNA found on the ends of chromosomes
  - that protect the ends of chromosomes
  - repeated sequences of DNA at the ends of each chromosome in eukaryotic cells
* are repetitive DNA sequence flanking the end of linear chromosomes
  - base structures at the ends of eukaryotic chromosomes
  - stretches of DNA located at the ends of linear chromosomes
  - segments of DNA found at the tip of each chromosome in nonbacterial cells
  - specialized DNA-protein complex at ends of linear chromosomes
* are specialized structures found at the end of linear, eukaryotic chromosomes
  - that are important in maintaining chromosomal stability
  - structurally and functionally complex
  - structures at the ends of the chromosome that play a critical role in cell division
  - tasteful strands of nonsense DNA that decorate ends of chromosomes
* are the ends of chromosomes, which get a bit shorter with every cell division
  - natural ends, the tips, of a linear chromosome
  - physical ends of linear eukaryotic chromosomes
  - protective caps on the ends of chromosomes
  - stable ends of linear chromosomes in eukaryotes
  - tips of chromosomes in nearly all plants and animals, including humans
  - yardsticks measuring a cell's life expectancy
* become gradually shorter with every somatic cell replication.
* can break off as a result of radiation exposure, oxidative damage or various other means.
* compensate for incomplete semi-conservative DNA replication at chromosomal ends.
* consist of repetitive sequences that reside at the end of a linear chromosome.
* degrade as the cells divide and their shortening causes cell death.
* form large loop structures called telomere loops, or T-loops.
* help maintain chromosome integrity.
  - chromatin
  - part of chromosomes
* keep the individual strands of DNA in our cells from looping or connecting to one another.
* protect chromosomes from fraying and are believed to be involved in the ageing process
  - fusion and degradation
  - the DNA from degradation
* serve to assure that a chromosome is replicated properly each time a cell divides.
* shorten as cells divide and grow older.
* shorten during ageing of human fibroblasts
  - aging of human fibroblasts
* shorten each time a cell divides, and continuously erode as an animal ages
  - the chromosomes replicate
  - progressively with each cell division, leading to cellular senescence
  - slightly after each cell division
  - with successive cell divisions in normal somatic cells
* shrink with each cell division, until they become so short that they tell the cell to die.
* somewhat resemble the aglets on the ends of shoelaces.
* start out long enough to handle a great many scissor snips.
* tend to be long at birth, and shorten as the animal ages
  - form associations with each other
+ Telomerase: Enzymes :: Chromosomes
  * The telomeres are disposable buffers blocking the ends of eukaryotic chromosomes. Telomeres are destroyed during cell division, and are remade by the enzyme telomerase.