LC 3.3 - Ageing and Biological Events

Question 1

Describe the ‘Disposable soma theory’?

Answer 1

Keeping the body going from day-day is metabolically expensive. The proportion of genome invested in maintenance and repair is enough for as long as the animal is EXPECTED to survive in the wild.

Question 2

Is there a genetic programme designated to ageing?

Answer 2

No

Question 3

What is the primary cause of ageing?

Answer 3

Damage

Question 4

How is longevity regulated?

Answer 4

Genes influencing and contributing to resistance and repair

Question 5

When does ageing begin to ‘occur’ and through what means?

Answer 5

Conception

Somatic mutation

Question 6

How does oxygen lead to molecular damage?

Answer 6

Reactive oxygen species (free radicals) are formed as by-products from respiration in mitochondria. They target DNA within the cell nucleus and mitochondria

Question 7

What is the function of telomeres?

Answer 7

Protect the ends of chromosomes

Question 8

What happens to telomeres under biological stress and what is this significance to ageing?

Answer 8

Telomeres shorten with cell division, however this is accelerated under stress
Prematurely shortened telomeres are associated with age-related diseases and diminished survival

Question 9

What degree of longevity is influenced by genetics?

Answer 9

About 25% - these genes influence the body’s capacity for maintenance and repair

Question 10

Name six factors influencing age trajectories?

Answer 10

Genes
Nutrition
Lifestyle
Environment
Socio-economic status
Attitudes