3.6 Evolution of Species

Question 1

Define mutation.

Answer 1

A random change to genetic material: the only source of new alleles.

Question 2

Name 3 things a mutation may be.

Answer 2

Neutral, advantageous or disadvantageous.

Question 3

Name environmental factors which increase the rate of mutation.

Answer 3

Radiation and some chemicals.

Question 4

What can new alleles from mutation result in?

Answer 4

Plants and animals becoming better adapted to their environment.

Question 5

What does evolution do response to changing environmental factors conditions require?

Answer 5

Variation within a population.

Question 6

When does natural selection occur? (5 points)

Answer 6

(1) More offspring are produced than the environment can sustain

(2) There are selection pressures

(3) Only the best adapted individuals survive to reproduce

(4) They pass on their favourable alleles that give the selective advantage.

(5) These alleles increase in frequency in the population

Question 7

When does speciation occur? (5 points)

Answer 7

(1) Part of a population becomes isolated by an isolation barrier

(2) Different mutations occur in each subpopulation

(3) Natural selection selects for different mutations in each group

(4) Due to different selection pressures

(5) Each subpopulation evolves until their genetic differences make them two different species

Question 8

Name 3 things isolating barriers can be.

Answer 8

Geographical, ecological or behavioural