Answer:
a. Damage is caused by free radicals that slow down the cell-duplication process.
c. Aging may be caused by the inevitable loss of the ability of cells to duplicate perfectly.
Explanation:
The free radical theory of aging states that aging is caused by accumulation of damage inflicted by reactive oxygen species (free radicals). It proposes that organisms age because they accumulate oxidative damage, Now,this damage comes from reactive oxygen species (ROS), which are partially reduced metabolites of molecular oxygen (free radicals) generated as products of metabolic reactions. Thus, these free radicals cause damage that slow down the cell-duplication process.
Also, Aging may be caused by the inevitable loss of the ability of cells to duplicate perfectly. (SENESCENCE).
When senescence occurs (i.e inevitable loss of the ability of cells to duplicate perfectly) there is progressive deterioration of physiological function, an intrinsic age-related process of loss of viability and increase in vulnerability of cells.
