GEN-3000 Lecture 4: Chapter 4
6 Feb 2017
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Document Summary
Chapter 4 - extensions and modifications of basic principles. Allele : one of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome. Loss-of-function mutation : mutation that results in reduced or lost protein function. Null allele : a mutant copy of a gene at a locus that completely lacks that gene"s normal function. Gain-of-function mutation : a mutation where the affected gene now expresses/possesses a new molecular function or a new pattern of gene expression. Neutral mutation : changes in dna sequence that is neither beneficial nor harmful to the organism. Dominance : phenotype of the heterozygote is the same as the phenotype of the one of the homozygotes. Incomplete dominance : phenotype of the heterozygote is intermediate (falls within the range) between the phenotypes of the two homozygotes. Codominance : phenotype of the heterozygote includes the phenotypes of both homozygotes.
