6. Evolution of Species

Question 1

Mutation

Answer 1

Random change to genetic material and the only source of new alleles

Question 2

Mutations may be

Answer 2

Neutral, advantageous or disadvantageous to survival

Question 3

Environmental factors which can increase the rate of mutation

Answer 3

Radiation and some chemicals

Question 4

New alleles can result in

Answer 4

Plants and animals become better adapted to their environment

Question 5

Adaption

Answer 5

Makes an organism well suited to survival in its niche

Question 6

Variation within a population

Answer 6

Makes it possible for a population to evolve over time

Question 7

Natural selection occurs when

Answer 7

There are selection pressures (this can be caused by a species producing more offspring than the environment can sustain)

Question 8

The best adapted individuals survive

Answer 8

Passing on the favourable alleles

Question 9

Speciation

Answer 9

The creation of a new species

Question 10

Stages of speciation

Answer 10

Isolation - 3 types of barrier behavioural, ecological and geographical.
Mutation - diffrent mutations occur within the sub populations.
Natural selection - selects different mutations within each group due to different selection pressures.
Different species formed - over time each sub population evolves until they become so genetically different that they are now a different species from each other.