Telomerase activity is controlled during development and is extremely low in somatic (body) cells, virtually undetectable. These somatic cells age because they do not frequently use telomerase.
Telomeres are repetitive sections at the very ends of chromosomes that are present in a variety of eukaryotic species, including humans and unicellular protists.
Each round of DNA replication wears down a little portion of the telomeres, which serve as caps to safeguard the interior chromosomal regions.
Most somatic (body) cells do not typically have telomerase activity, but certain adult stem cells and germ cells—the cells that produce sperm and eggs—have.
Adult germ cells, tumor cells, and fetal tissues all contain telomerase. Telomerase activity is controlled during development and is extremely low in somatic (body) cells, virtually undetectable. These somatic cells age because they do not frequently use telomerase.
This stage of life when gray hairs become overwhelming in number and he has more gray hairs than brunette( brown hair) is called middle adulthood. Middle adulthood spans from 20 to 40 years of life which may be defined differently for different culture and country.
Robert is in his late mid adulthood somewhere near 40 at this age hair generally grow grey.
