7.2 Populations

• What is a population?

  ● A group of organisms of the same species in a particular space at a particular time

  ● That can (potentially) interbreed (to produce fertile offspring)
• What is a gene pool?

  All the alleles of all the genes in a population at any one time
• What is allele frequency?

  Proportion of an allele of a gene in a gene pool (decimal or percentage)
• What does the Hardy-Weinberg principle state and what are the conditions

  under which the principle applies?

  ● 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
• What is the Hardy-Weinberg equation?

  $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 squared = frequency of homozygous (usually dominant) genotype

  ● 2pq = frequency of heterozygous genotype

  ● q squared = frequency of homozygous (usually recessive) genotype