Question

The theory of ageing holds that aging is due to

• A. Random mutation in DNA of somatic cells.
• B. Increased cross-linkage of collagen and other proteins.
• C. Cumulative result of damage to tissues by free radical.
• D. All of the above.

Answer 1

Answer: (D)

All of the above.

The somatic mutation theory of ageing states that the accumulation of random mutations inactivates genes, that are important for the functioning of the somatic cells of various organ systems of the adult, which results in a decrease in organ function.

The cross-linking theory of ageing assumes, that with increasing age, tendons, skin, and even blood vessels lose elasticity. This is due to the formation of crosslinks between or within the molecules of collagen, that give elasticity to these tissues.

The free radical theory of ageing states, that organisms age because cells accumulate free radical damage over time. Free radical damage is closely associated with oxidative damage.