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Published byKerry Rice Modified over 9 years ago
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Chapter 14: Mendel and the Gene Idea
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Genetic Terminology Character – Trait True-breeding Hybridization – P generation – F 1 generation – F 2 generation
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Mendel’s Ideas For each trait an organism inherits two alleles If the alleles are different… – Dominant – Recessive
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Mendel’s Laws Law of Segregation – Alleles for each character separate during gamete formation
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Mendel’s Laws Law of independent assortment – Pairs of alleles separate individually
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Rules of Probability Rule of multiplication – Examples 2 coins land heads up Parent is YyRr, gamete will carry Y, R Parents are YyRr, offspring will be YYRR Rule of Addition – Event can occur two or more ways – Example Two ways to produce heterozygote if parents are Pp
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Rules of Probability PpYyRr x Ppyyrr What is the probability of offspring having recessive phenotype for at least two of the three traits – ppyyRr – ppYyrr – Ppyyrr – PPyyrr – ppyyrr
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Types of inhertiance Incomplete dominance – Snapdragons Co-dominance – M,N,MN blood groups Multiple alleles – ABO blood groups Surface carbohydrate Alleles
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ABO Blood Groups
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Types of Inheritance Pleiotropy – Sickle Cell Anemia Epistasis – Coat color in mice Polygenic traits – Eye color – Skin color
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Pedigrees
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Genetic Disorders Recessive – Tay Sachs – Cystic Fibrosis – Sickle Cell Anemia – Phenylketonuria (PKU) Dominant – Achondroplasia – Huntington’s Multifactorial – Heart disease, diabetes, cancer, alcoholism, schizophrenia, manic-depressive disorder
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Chapter 15: The Chromosomal Basis of Inheritance
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Thomas Morgan’s Experiment White type restricted to males – Sex-linked Recessive- – Father to son – Linked genes Passed as unit Same chromosome
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Sex-Linked Disorders Duchenne’s – Loss of muscle strength and coordination Hemophilia – Failure of blood to clot Red-green colorblindness – Primarily males
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Chromosomal Complications Non-disjunction – Aneuploidy Trisomy – Down’s Syndrome – Patau Syndrome – Edward’s Syndrome – Klinefelter’s Syndrome Turner’s Syndrome
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Chromosomal Complications Deletion – Cri-du-chat Translocation – Chronic myelogenous leukemia Inversions Duplications
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Chi Square Analysis Used to determine if there are deviations for the phenotypic ratio of the F 2 generation within the limits expected by chance – Null hypothesis – Formula X 2 = ∑ (o – e) 2 e
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Chi Square Analysis Degrees of freedom Chi square – Critical value Reject hypothesis Probability1234 0.053.845.997.829.49 0.016.649.2111.3013.20 0.00110.813.816.318.5
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