Chapter 19.2

Question 1

microevolution

Answer 1

Gradual changes in allele frequencies in a population

Question 2

processes that may lead to changes in gene frequencies

Answer 2

1.genetic mutation
2. gene flow (migration)
3. non- random mating
4. genetic drift (small populations)
5. natural selection

Question 3

1. Mutations

Answer 3

• change that occurs in DNA of an individual
• may be neutral, advantageous or detrimental

Question 4

2. Gene Flow

Answer 4

describes new movements of one allele from one population to another due to migration.
- increases genetic diversity within population, decreases genetic diversity between populations

Question 5

3. Non- Random Mating

Answer 5

mating based on physical appearance or behaviour

Question 6

4. Genetic Drift

Answer 6

occurs in small populations, change in allele frequency due to chance events
Two types : founder effect, bottleneck effect

Question 7

Founder Effect

Answer 7

When a few individuals from a population start a new isolated population

Question 8

Bottleneck Effect

Answer 8

gene pool change from sudden decrease in population size, often seen in species on the edge of extinction

Question 9

Natural selection

Answer 9

Those who are better able to survive and reproduce will pass on their favourable traits to the next generation

Question 10

Speciation

Answer 10

formation of a new species

Question 11

Geographic isolation

Answer 11

• The separation is caused by physical obstacles (mountain ranges, rivers, bodies of water)
• gene flow between isolated group and the main population stops
• groups becomes so different - 2 different species (incapable of mating with one another)

Question 12

Reproductive Isolation

Answer 12

• can be caused by geographic isolation
• occur when organisms in a population can no longer mate and produce offspring even following the removal of physical barrier