Ageing 2-2

There is a biological time table which regulates childhood adolescent and death.

Errors in maintenance repair and defence responses leads to death.

X. Wear and tear theory. Cells and tissues wear out overtime. Dr August weismann 1882.

X. Rate of living theory. The greater and organisms rate of oxygen basal metabolism the shorter its life span. Dr Rollo emphasizes modified version of this theory. 

X. Cross linked proteins accumulate and slow down body processes. Johan B 1942.

Somatic DNA damage theory. DNA damage and mutations continue over time and poor repair accumulates which creates defects and decline. 

Dr hayflick argues that human cells have the ability to divide approximately 50 times about after which is the simplest of dividing. Hayflick limit theory of aging.  Teleomeres shorten with each successive cell division. When there acquire critical length the cell stops replicating and dies of.