8.3 gene pools

Question 1

what are the conditions of the Hardy-Weinberg equilibrium?

Answer 1

• there are no mutations
• there is random mating
• the population is large
• the population is isolated
• there is no selection pressure

Question 2

what is a population bottleneck?

Answer 2

the effect of an event or a series of events that dramatically reduces the size of a population and causes a severe decrease in the gene pool of the population, resulting in large changes in allele frequencies and reduction in genetic diversity

Question 3

what is the fouder effect?

Answer 3

the loss of genetic variation that occurs when a small number of individuals become isolated, forming a new polulation with allele frequencies not representative of the original population

Question 4

what are the three types of selection?

Answer 4

• stabilising
• directional
• disruptive

Question 5

what is stabilising selection?

Answer 5

natural selection acting to conserve what is already present in the population, reducing variation so that the frequency of some alleles is very high but other alleles are greatly reduced

Question 6

what is directional selection?

Answer 6

when an environmental pressure is applied to a population, showing a change from one phenotypic property to a new more advantagrous one

Question 7

what is disruptive selection?

Answer 7

an increase in the diversity of the population rather than a trend in one particular direction

Question 8

what is a genetic drift?

Answer 8

the random changes in the gene pool of a population that occur by chance, not because they confer any advantage or disadvantage to the offspring