Replicative cell senescence

Replicative cell senescence is a process that involves the shortening of telomeres (regions at the end of chromosomes). This occurs as in most somatic cells Telomerase (an enzyme that prevents the telomeres shortening by solving the end replication problem) is turned off. This means that in each replication a small region of the telomere is lost each time as the ends cant be replicated without the presence of Telomerase. This mechanism is used to prevent cancers by ensuring cells have a finite lifespan.