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The Hardy-Weinberg Principle. D.4.1-3 Chapter 15. Hardy-Weinberg Principle. It is useful in determining how fast a population is changing or in predicting the outcomes of matings or crosses Used to calculate frequencies of alleles, genotypes, or phenotypes.
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The Hardy-Weinberg Principle D.4.1-3 Chapter 15
Hardy-Weinberg Principle • It is useful in determining how fast a population is changing or in predicting the outcomes of matings or crosses • Used to calculate frequencies of alleles, genotypes, or phenotypes
D.4.1: Explain how the Hardy-Weinberg equation is derived • Allele Frequency (p + q = 1) • p = frequency of the dominant allele • q = frequency of the recessive allele • Frequencies of alleles must add up to 1 so, p + q = 1 • Ex: If p = 0.25 (25%), then q = 0.75 (75%)
D.4.1: Explain how the Hardy-Weinberg equation is derived • Genotype Frequency (p2 + 2pq + q2 = 1) • p2 = homozygous dominants (AA) • 2pq = heterozygotes (Aa) • q2 = homozygous recessives (aa) • Frequencies of alleles must add up to 1 so, p + q = 1 • Ex: If p = 0.25 (25%), then q = 0.75 (75%)
D.4.1: Explain how the Hardy-Weinberg equation is derived • p2 = chance of receiving 2 dominant alleles • 2pq = chance of receiving a dominant and recessive allele • q2 = chance of receiving 2 recessive alleles • There are 2 ways of to get Aa, depending on which parent contributes which allele • These represent all the possible genotypes for a population, therefore the total number of each should total 100%
D.4.2 • Calculate allele, genotype, and phenotype frequencies for two alleles of a gene, using the Hardy-Weinberg equation • See homework problems
D.4.3: State the assumptions made when the Hardy-Weinberg equation is used • Assumptions that must be fulfilled in order for calculations to work: • Very large population size • No emigration/immigration • No mutation • Random mating • No natural selection (allele specific mortality) • Ex: sickle-cell anemia = bb (lethal)