Question

How and what kind of cells deal with telomere shorterning?

How do some cells resolve the problem of telomere shortening? What kinds of cells usually do this?

Answer 1

Chromosomes have strecthes of DNA called "Telomeres" .These telomeres not only protect the genetic data but also prevent the stciking of the ends of the chromosomes which otherwise destroy the genetic information of an organism and ensures chromosome stability. Telomeres also provide a mechanism for counting the cell divisions.Whenever the cell divides the telomere gets shorter (S phase).as the DNA replication is bidirectional and DNA polymerases are unidirectional which results nearly 50-200bp DNA unreplicated at 3' end.when they get too short the cell becomes inactive or senescent or it dies.An enzyme named telomerase adds bases to the ends of telomeres. In young cells, telomerase keeps telomeres from wearing down too much. But as cells divide repeatedly, there is not enough telomerase, so the telomeres grow shorter and the cells age.

Telomerase remains active in sperm and eggs which are passed from one generation to the other in absence of telomerase these cells would have undergone extinct,

In case of canceous cells also the activity of telomerase helps the cells escape death.Thus it is the enzyme telomerase which counteracts the telomere shortening in immortal cells like cancer cells