* Gregor Johann Mendel 1822-1884

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Chapter 3: Mendelian Genetics. Two main hypotheses on how traits are transmitted: *blending inheritance * particulate inheritance. * Gregor Johann Mendel 1822-1884. Pisum sativum. -Why study (or experiment with) the garden pea?. -Mendel followed several visible features:. - PowerPoint PPT Presentation

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*Gregor Johann Mendel 1822-1884Chapter 3: Mendelian GeneticsTwo main hypotheses on how traits are transmitted:*blending inheritance *particulate inheritancePisum sativum-Why study (or experiment with) the garden pea?-Mendel followed several visible features:

1The Monohybrid Cross-Example:

XTallDwarfP1F1 all Tall

F22Mendels Principles of Inheritance*unit factors1. Unit factors occur in pairs

TallDwarfP1Factors: DD dd Dd32. Dominance/RecessivenessMendels Principles of Inheritance cont

XTallDwarfP1DD ddF1 all Tall

TallDd4Mendels Principles of Inheritance cont3. Segregation DD dd

XTallDwarfP1F1 all Tall

TallDd5DdDdTallTallMendels Principles of Inheritance contWhat about the F2?Self cross F1:ddDDDdDdFour possible combinations result in F2:12346The Test Cross: One Character-How to distinguish DD or Dd genotype?*Test cross

7Punnett SquaresDDdTallTallSelf cross F2:Dd DdXGamete formation:d8Sample Problem:Albinism in humans is inherited as a simple recessive trait. Determine the genotypes of the parents and offspring for the following families. When two alternative genotypes are possible, list both. (A) Two non albino (normal) parents have five children, four normal and one albino. (B) A normal male and an albino female have six children, all normal.9Mendelian inheritance is based on probability

Example- coin toss10The Rule of Addition

11Chi-Square Analysis:p value (probability): consider as a percentage (i.e. 0.05 = 5%)