BIOLOGY 2C03 Lecture Notes - Lecture 3: Wild Type, Tyrosinase, Gene Duplication
23 Apr 2016
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Document Summary
If it is oberserved in both homo and hetero genotypes then it is seen as dominant. Phenotpyes are a consequence of the proteins produced by alleles in a gene. Haplosufficient wt allele is dominant: the r allele produces and enzyme that must generate 40 or more units of catalytic activity to dive critical rxn step, and r produces around 0. The rr produces 40 units, hetero produces 40 which is sufficient to produce the phenotype. They are considered haplo sufficient because one copy is enough to produce the wt phenotype. Recessive haploinsufficient allele: 18 catalytis units are needed to get past the enzyme step. T allele produces 10 units and t2 produces 5 units. Thus only tt will generate enough units to get past 18. 10 + 5 is not enough, so heter will not produce the wild type phenotype. Called this because a single copy is not enough. Loss of function: loss of functional activity of a gene product.
