ANTHR-140 Lecture Notes - Lecture 23: Heritability, Biological Anthropology, Genotype
14 Sep 2020
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Document Summary
Genotype and phenotype at the level of species. Genotype set of genes an individual possesses. Phenotype physical expression of those genes. Can subdivide traits based on phenotypic distributions. Traits that show discontinuous variation a few easily distinguishable phenotypes (usually) Usually results from inheritance involving one gene. Ex. 2: abo blood group shows this discontinuous variation (three alleles and the resulting phenotypes are aa and ao (a dominant), bb bo (b dominant), oo (o dominant), ab (ab dominant) Two alleles for this gene (t,t) the ability to taste is dominant to the ability not to taste a substance. Traits showing continuous variation great variety of phenotypes. One grade or category of phenotypes would grade into the next category. Traits showing continuous variation usually have a polygenic basis. Polygenic: two or more genes interacting to produce the phenotype. These traits usually affected more by environment factors than single genes are. Formula for calculating the number of genotypes in a polygenic system.
