Week 4 Lab alternate_F22-4

LS7B Week 4 Lab – Genetics Review Name: ___________________________ Section: _____________ Activity 1 – Labrador crosses 1. Using directions provided by your instructor and data table on the supplemental handout, determine the unique genotype of each group of dogs. Group A: ______________________ Group B: ______________________ Group C: ______________________ Group D: ______________________ Group E: ______________________ Group F: ______________________ Group G: ______________________ 2. What are the expected genotypic (a) and phenotypic (b) proportions of F 1 offspring from mating between two black labs that are both double heterozygotes ( BbEe )? a. Genotypic Proportions: Genotype Expected Proportion Genotype Expected Proportion Genotype Expected Proportion BBEE BbEE bbEE BBEe BbEe bbEe BBee Bbee bbee b. Phenotypic Proportions: Phenotype Expected Proportion Phenotype Expected Proportion Phenotype Expected Proportion black chocolate yellow 3. Refer to the results of Cross 3 (reproduced in the table immediately below) to answer the following questions. Cross Mating Between No. Pups No. Black Pups Prop. Black Pups No. Choc. Pups Prop. Choc. Pups No. Yellow Pups Prop. Yellow Pups 3 Group D (black) Group D (black) 51 26 0.510 14 0.275 11 0.216 a. Explain why the expected phenotypic proportions of this cross (see Question 3) differ from the observed proportions of actual puppies born from Cross 3. b. If Cross 3 resulted in 5000 puppies, rather than 51, do you think the observed and expected values would more or less similar? Explain your answer.