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Free Classroom Resources from HHMI for Teaching Evolution, Part 2 Megan Stine stinem@hhmi.org June 19, 2014
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Evolution: Behind the Scenes
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Evolving Switches, Evolving Bodies Film guides Virtual lab Classroom activities: – Using Genetic Crosses to Analyze a Stickleback Trait – Modeling the Regulatory Switches of the Pitx1 Gene in Stickleback Fish
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Evolving Switches, Evolving Bodies Film http://www.hhmi.org/biointeractive/making- fittest-evolving-switches-evolving-bodies http://www.hhmi.org/biointeractive/making- fittest-evolving-switches-evolving-bodies
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Which phenotype is dominant? Assumption: single-gene trait, 2 alleles, normal dominance Cross between a marine stickleback and one from Bear Paw Lake Parents are homozygous F is dominant, f is recessive
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Predict the results of the crosses FF f f Ff Pelvic spines present:absent = 0:1 1:0 Ff F f FF Ff ff Pelvic spines present:absent = 3:11:3 1 st generation2 nd generation
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Sorting by Phenotype With pelvic spinesWithout pelvic spines
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Do the data support your hypothesis? Sort the F 1 cards: – Fish with pelvic spines – Fish without pelvic spines Sort the F 2 cards Ratio of fish with:without pelvic spines in F 1 ? Ratio of fish with:without pelvic spines in F 2 ? 1:0 3.4:1 Was our initial assumption correct? Is this a single-gene trait? Was your hypothesis correct? Which phenotype is dominant?
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Virtual Lab
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Natural Selection in Humans Film guides Classroom resources: – Nature of Science – Mendelian Genetics, Pedigrees, and Chi- square Analysis – How Fibers Form – Population Genetics
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Natural Selection in Humans Film http://www.hhmi.org/biointeractive/making- fittest-natural-selection-humans http://www.hhmi.org/biointeractive/making- fittest-natural-selection-humans
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Mendelian Genetics Activity Punnett squares Pedigree analysis Pedigree creation Chi-square analysis Data prediction Important notes: – A is normal allele – S is sickle cell allele – AA has normal RBC phenotype – AS has sickle cell trait – SS has sickle cell disease
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Question #1: Intro Punnett AS A S Chance of normal RBC in high and low oxygen? Chance of SCD? Chance of 3 children with SCD? Chance of 2 children with sickle cell trait and 1 with SCD? Child without SCD, what chance he/she has trait? AA AS SS 1/4 1/64 1/16 2/3
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Question #6: Intro Pedigree Genotype of: – 1 st gen male? – 2 nd gen daughter? – Individual #3? If family moves to lowlands of E. Africa, 4/5 males will have two genetic advantages. What are they? AS SS AS
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Human Evolution Click & Learn
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Teacher Guides
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Holiday Lecture Series
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BioInteractive.org
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Coming in Fall 2014…
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Thank you for your time and attention! stinem@hhmi.org Sign up for our newsletter at biointeractive.org Like us on Facebook!
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