Questions and Answers GIZMOS: Student Exploration: Hardy-Weinberg Equilibrium

Student Exploration: Hardy-Weinberg Equilibrium Vocabulary: allele, genotype, Hardy-Weinberg equation, Hardy-Weinberg principle, heterozygous, homozygous, Punnett square Prior Knowledge Questions (Do these BEFORE using the Gizmo.) Suppose the feather color of a bird is controlled by two alleles, D and d. The D allele results in dark feathers, while the d allele results in lighter feathers. D d D d 1. Suppose two Dd birds mate. What percentages of DD, Dd, and dd offspring would you predict? Use the Punnett square at right to help determine your answer. DD 25% Dd 50% dd 2. In this situation, what ratio of heterozygous (Dd) to homozygous (DD and dd) offspring would you expect to find? Heterozygous 1 : homozygous 1 Gizmo Warm-up Many factors—immigration, natural selection, hunting, and so forth—can influence the composition of a population. To determine if one of these factors is affecting a population, it is useful to know what a population looks like when none of these factors is present. In 1908, Godfrey Hardy and Wilhelm Weinberg independently discovered the laws that govern such populations. These laws can be explored in the Hardy-Weinberg Equilibrium Gizmo™. 1. The parrots you see on the SIMULATION pane represent