CH12

Question 1

Reducing calories in an animal’s diet can increase its lifespan. How?

Answer 1

it triggers a repairing response (stress) in the cells

Question 2

How do the stress- response genes work to fight the aging process?

Answer 2

if the gene is switched on constantly, it can repair damaged cells continuously (eg. if there’s a famine) which fights the effects of aging

Question 3

What does the P53 tumor suppressor protein do?

Answer 3

stops damaged cells from dividing, which protects from cancer, but it can stop too many cells, causing damage to tissues

Question 4

Why doesn’t natural selection remove the P53 gene?

Answer 4

Because it has detrimental effects later in life (benefits early in life), after the individual has had offspring. So natural selection doesn’t remove it because it isn’t detrimental until after the genetic material is passed on

Question 5

Aging arises