IMED2004 Lecture Notes - Lecture 22: Zygosity, Wild Type, Somatic Cell
25 Mar 2020
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All cells of embryo will heterozygous mtwt. Gametes will either be mt or wt . Heterozygote- mix of normal & abnormal protein. Loss of function mutations: some examples differ from these standard expectations. Where both alleles of a gene are transcribed: monoallelic. Only one of the 2 copies of a gene is active while the other is silent. Frequently initiated early in development then stably maintained. Inheritance of multiple alleles, including abo blood groups. It"s not always dominant-recessive: non-mendelian inheritance patterns: Sex-linked characteristics (x & y) phenotypes expressed: many phenotypes can be influenced by the environment. Dominance, incomplete dominance & codominance: (continued: complete & incomplete dominance, how does the phenotype of heterozygote relate to that of homozygotes, amount of red pigment varies, human example of curly, wavy and straight hair. Incomplete dominance (in gene affecting hair texture: curly, wavy, straight, phenotypic ratio= 1:2:1.
