LC 3.3 Biological Events

Question 1

What relationship does age have with mortality?

Answer 1

mortality increases exponentially

Question 2

What argument exists that opposes the idea of ageing being intrinsic for the purpose of making animals die/expire for the continuation of evolution?

Answer 2

Survival in the wild is so dangerous that very few individuals survive long enough to experience ageing due to life experience being truncated by extrinsic mortality.

Thus, this elderly age range is ‘shadowed’ from natural selection because it is so rarely reached and no angle of approach or mechanism for evolution of the older years is possible in the wild.

Question 3

What theory of ageing takes into account the effects of high levels of extrinsic mortality in the wild?

Answer 3

Disposable Soma Theory

This is the idea that it is only worth investing enough energy in maintenance of the body to keep it in reasonable condition for the years that the wild would expect it to survive and this limited repair mechanism does not favour longevity. This is to save resources.

Question 4

What is ageing at a cellular level primarily caused by?

Answer 4

Telomere shortening
Random molecular & DNA damage
Free radical damage (most often to mitochondria)

Question 5

What accelerates telomere shortening?

Answer 5

Biochemical stress

Question 6

What accounts for the individuality of human ageing?

Answer 6

Genetics
Nutrition
Lifestyle
Socioeconomic status

Question 7

Which genes contribute to individuality of ageing? What proportion of age individuality is attributable to these genes?

Answer 7

Genes which are responsible for managing maintenance and repair - 25%

Question 8

What diet is considered the best to prolong longevity?

Answer 8

Mediterranean diets

Question 9

By how much is life expectancy increased daily?

Answer 9

4 hours in UK