Lec18+2010 - Lecture 18: Human Genetics, Disease Wednesday...

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Lecture 18: Human Genetics, Disease Wednesday 11/03/10 18-1 Reading: Ch. 14, pp. 276-281 Supplements: Web Activity 15.2 Fall 2010, Bio 93, O’Dowd and Warrior, UCI - Copyright: All rights reserved
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Variations from Classic Mendelian Genetics 5. Epistasis: a gene at one locus alters the phenotypic expression of a gene at a second locus. 4. Pleiotropy: one gene affects > one phenotypic character. 6. Polygenic inheritance: multiple genes are responsible for a phenotype. 7. Environmental impact: genetically identical individuals show different phenotypes as a result of environmental factors. 18-2 Fall 2010, Bio 93, O’Dowd and Warrior, UCI - Copyright: All rights reserved 1. Incomplete dominance: heterozygotes have a phenotype intermediate to the two alleles. 2. Co-dominance: the phenotype of both alleles is fully expressed in heterozygotes. 3. Multiple alleles: more than two alleles affect a phenotype
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One gene affects > one phenotypic character. In sickle cell anemia mutation of one gene causes many symptoms. Fig. 14.15 18-3 Fall 2010, Bio 93, O’Dowd and Warrior, UCI - Copyright: All rights reserved 4. Pleiotropy
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5. Epistasis 18-4 Bruce Willis has dominant alleles for the bald gene and the widow’s peak gene. The bald allele B is epistatic to widow’s peak W A gene at one locus alters the phenotypic expression of a gene at a second locus Fall 2010, Bio 93, O’Dowd and Warrior, UCI - Copyright: All rights reserved
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Coat color in mice depends on two genes. Gene 1 determines whether the coat is black (
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This note was uploaded on 01/25/2011 for the course CHEM 1LB taught by Professor Edwards during the Fall '08 term at UC Irvine.

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Lec18+2010 - Lecture 18: Human Genetics, Disease Wednesday...

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