Topic 7 - Populations

Question 1

What is a gene pool?

Answer 1

The total number of alleles present within a population.

Question 2

What is allelic frequency?

Answer 2

The proportion of a specific allele within the gene pool expressed as a decimal or percentage.

Question 3

What factors increase and decreased the size of the population?

Answer 3

• birth rate and immigration increase the population
• Death rate and emigration increase the population

Question 4

What are the environmental influences on populations?

Answer 4

Abiotic factors, including temperature, water availability, and light intensity
Biotic factors, including predation competition and disease

Question 5

What is the hardy Weinberg principle used for?

Answer 5

To predict the frequency of alleles genotypes and phenotypes within a population.

Question 6

What conditions need to be met in order for the hardy Weinberg principle to work?

Answer 6

1. Large population sized minimise genetic drift.
2. No mutations that change the allele frequencies.
3. Random mating between the individuals.
4. No migration into or out of the population.
5. No selection for or against specific alleles.

Question 7

What is a hardy Weinberg equation?

Answer 7

P2 + 2pq + q2 = 1

Question 8

What do the different letters mean in the hardy Weinberg equation?

Answer 8

P = frequency of the dominant allele
Q = frequency of the recessive allele
P2 = proportion of homozygous dominant individuals
Q2 = proportion of homozygous recessive individuals
2pq = proportion of heterozygous individuals