9C Genetic drift and gene flow

Question 1

Founder effect

Answer 1

The formation of a new population by a non - representative sample of individuals from the parent population

Question 2

Genetic drift

Answer 2

A change in the frequency of alleles in a gene pool due to chance events

Question 3

Example of genetic bottle neck

Answer 3

There were originally red and yellow bugs however one day they were sprayed by a pesticide and this killed them all. There were two bugs that were coincidentally yellow that survived under the leaf and therefore reproduced and all the offspring were yellow

Question 4

Example of the founder effect

Answer 4

The yellow bugs were carried onto the other island by a cyclone. By chance they are yellow but this does not mean they are fitter by red bugs. The two main bugs reproduced and therefore caused the offspring to be yellow. There is not much genetic variation.

Question 5

Gene flow

Answer 5

The transfer of genetic information from one population into a population by migration

Question 6

List some of the mechanisms that can cause gene flow

Answer 6

Migration e.g., pollen transferring from plant to plant.
Natural selection
Mutation
Genetic drift