Teacher Notes



Teacher Notes
Publication No. 10335
Gene Pool and Natural SelectionSuper Value Laboratory KitMaterials Included In KitGene Pool and Natural Selection Worksheet Additional Materials Required(for each lab group) Safety PrecautionsDo not use pop beads with small children as they can inhale or ingest them. Follow all other normal laboratory safety rules. DisposalAll materials may be stored for future use. Teacher Tips
Correlation to Next Generation Science Standards (NGSS)^{†}Science & Engineering PracticesAnalyzing and interpreting dataDeveloping and using models Disciplinary Core IdeasMSLS1.B: Growth and Development of OrganismsMSLS3.A: Inheritance of Traits HSLS3.B: Variation of Traits Crosscutting ConceptsScale, proportion, and quantityCause and effect Performance ExpectationsMSLS32. Develop and use a model to describe why asexual reproduction results in offspring with identical genetic information and sexual reproduction results in offspring with genetic variation. Answers to Questions{10335_Answers_Table_1}
p = 0.6
p = 0.51
The gene pools are not identical, but they are very similar. {10335_Answers_Table_2}
p = 0.65
The frequency of W in the gene pool has decreased from 0.40 to 0.35 in this example and the frequency of red has gone up from 0.60 to 0.65.
The W gene is not likely to be completely eliminated from the gene pool because of the heterozygous individuals carrying the recessive gene. Recommended Products


Student Pages


Student PagesGene Pool and Natural SelectionIntroductionWhat is a gene pool? What factors affect or change a gene pool over time? Concepts
BackgroundEarly in the 20th century the mathematician G. H. Hardy and the physician W. Weinberg recognized a mathematical relationship that represents the allele frequencies found in a population at equilibrium. The mathematical relationship became known as the HardyWeinberg Principle.
No real world population actually meets all of the HardyWeinberg criteria. The short term stability of many large populations, however, allows the population to be analyzed with the HardyWeinberg Principle and changes in gene frequencies within the gene pool can often be detected and theorized. {10335_Background_Figure_1}
The HardyWeinberg Principle’s mathematical statement is shown in Equation 1. {10335_Background_Equation_1}
where p = frequency of allele p The key to utilizing the mathematical statement on real populations depends on knowing the frequency of the homozygous recessive individuals in the population. This is because the phenotype is often clearly recognized and its frequency can be counted. Once q^{2} is known, then q can be determined by taking the square root of q^{2}. Since p + q = 100% or 1, p can then be calculated once q has been determined. Once p and q are known p^{2}, 2pq and q^{2} are all easily derived. q^{2} = 0.36 In summary, for this population the frequencies of alleles and genotypes would be as follows: q = W = 0.6 MaterialsPop beads, red, 60 Safety PrecautionsDo not use pop beads with small children as they might be swallowed or inhaled. Follow other standard laboratory rules. Procedure
Student Worksheet PDF 