3.7.2 - Populations

Question 1

What is a population?

Answer 1

● A group of organisms of the same species in a particular space at a particular time
● That can (potentially) interbreed (to produce fertile offspring)

Question 2

What is a gene pool?

Answer 2

All the alleles of all the genes in a population at any one time

Question 3

What is allele frequency?

Answer 3

Proportion of an allele of a gene in a gene pool (decimal or percentage)

Question 4

What does the Hardy-Weinberg principle state and what are the conditions
under which the principle applies?

Answer 4

● Allele frequencies will not change from generation to generation, given:
○ Population is large
○ No immigration / emigration (to introduce / remove alleles)
○ No mutations (to create new alleles)
○ No selection for / against particular alleles
○ Mating is random

Question 5

What is the Hardy-Weinberg equation?

Answer 5

p^2 + 2pq + q^2 = 1

p + q = 1

● p = frequency of one (usually dominant) allele of the gene
● q = frequency of the other (usually recessive) allele of the gene
● p^2 = frequency of homozygous (usually dominant) genotype
● 2pq = frequency of heterozygous genotype
● q^2 = frequency of homozygous (usually recessive) genotype

> if alleles are codominant, either can be assigned p and q

Question 6

carrying capacity

Answer 6

the maximum, size/number, of a population/species supported in a particular habitat/area/ecosystem

Question 7

species richness

Answer 7

number of species in a community

Question 8

species evenness

Answer 8

abundance of the different species