Topic 8- effect of genetic mutations

Question 1

What is the estimated rate of mutations occurring?

Answer 1

one mutation per 100,000 genes per generation

Question 2

What increases the rate of mutation?

Answer 2

Exposure to mutagenic agents

Question 3

Give examples of mutagenic agents

Answer 3

-High energy ionising radiation (alpha, beta or gamma radiation)
-Chemicals (such as nitrogen dioxide or benzopyrene from tobacco smoke)

Question 4

What is the effect of MOST gene mutations?

Answer 4

do not alter the polypeptide or only alter it slightly so that its structure or function is not changed

Question 5

What is the effect of mutations that significantly alter the polypeptide and result in a different shape?

Answer 5

may affect the ability of the protein to perform its function:
-shape of the active site on an enzyme changes, the substrate may no longer be able to bind to the active site
-A structural protein (like collagen) may lose its strength if its shape changes

Question 6

Polypeptides / proteins affect the phenotype of an organism via what?

Answer 6

-specific cellular mechanisms

Question 7

How can mutations impact the phenotype of an organism?

Answer 7

-If a mutation causes a major alteration in a polypeptide, then cellular mechanisms could be affected