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Chi- Squre Goodness of Fit Test. From Ch 3 Will also include information on di-hybrid crosses. Outline. Di-Hybrid Cross Mendel’s 2 nd Law Chi-Square Analysis corn data (phenotypes). DIHYBRID CROSS. Reveals Mendel’s 2 nd Law. Principle of Independent Assortment. 9:3:3:1.
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Chi- Squre Goodness of Fit Test From Ch 3 Will also include information on di-hybrid crosses
Outline • Di-Hybrid Cross • Mendel’s 2nd Law • Chi-Square Analysis • corn data (phenotypes)
DIHYBRID CROSS Reveals Mendel’s 2nd Law Principle of Independent Assortment 9:3:3:1
Independent assortment • Refers to alleles on different chromosomes!
What is the P that there are yellow and round seeds? • ¾ x ¾ = 9/16
Chi Square Statistical “Goodness of Fit Test” • Why do we use it? • . • To find out determine if probability are due to chance alone. An example of how to calculate a Chi Square
Objective • Complete corn worksheet • Set up Punnett Squares using the genotypes given • Compare expected data to observed data • Perform Chi Square Analysis
Corn Kernel Color • Color of aleurone masks endosperm color • Only with colorless aleurone can endosperm color be determined • Determined by several genes • Refer to genotypes in lab manual!
Gene interaction can occur:Epistasis is a form of gene interaction in which one gene masks the phenotypic expression of another.
Today there are: 3 crosses of corn F1 X F1 Multiple alleles are tested for expression in F2 generation
Note color differneces • Cross C • Cross D (darker color is purple) • Cross F (call purple, may look red!)
F1 phenotype F1 X F1 genotypes Yellow YYC’Rr X YYC’Rr Cross C
F1 phenotype F1 X F1 genotypes Purple yyPpRr X yyPpRr Cross D
F1 phenotype F1 X F1 genotypes Purple yyCcRr X yyCcRr Cross F
Genetic information regarding the corn color patterns are provided in your lab manual. The basis of these color patterns. CORN WORKSHEET IS DUE 2/28/08