3.7.2 Populations

Question 1

Define species

Answer 1

A group of organisms that can interbreed to produce fertile offspring.

Question 2

define population

Answer 2

all the organisms of a particular species that live in the same place

Question 3

define gene pool.

Answer 3

the range of different alleles existing for a particular locus within a population

Question 4

define allele frequency.

Answer 4

The proportion of a certain allele within a gene pool, expressed as a decimal or percentage.

Question 5

What is the Hardy-Weinberg principle?

Answer 5

Allows us to estimate the frequency of alleles in a population, as well as if allele frequency is changing over time

Question 6

Give the assumptions made by the Hardy-Weinberg principle.

Answer 6

• No mutations occur to create new alleles
• No migration in or out of the population.
• No selection, so alleles are all equally passed on to the next generation.
• random mating
• large population

Question 7

Explain the Hardy-Weinberg equation for calculating allele frequency.

Answer 7

The frequencies of each allele for a characteristic must add up to 1.0. The equation is therefore;
p + q = 1
where p= frequency of the dominant allele, and q= frequency of the recessive allele.

Question 8

Explain the Hardy-Weinberg equation for calculating genotype frequency.

Answer 8

The frequencies of each genotype for characteristics must add up to 1.0. The equation is therefore:
p squared + 2pq + q squared = 1
Where p squared = frequency of homozygous dominant, 2pq= frequency of heterozygous, and q squared = frequency of homozygous recessive