BIOSC-116 Lecture Notes - Lecture 28: Phenylketonuria, Melanin, Pleiotropy
26 Aug 2020
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Document Summary
Factors such as temperature, light, and altitude can affect the phenotypic expression of a genotype. Environment can affect the phenotypic expression of a genotype. Condition lethality: occurs with a particular type of allele which is lethal under only certain conditions. Sometimes results in death; if not treated. Studying pedigrees give insight to how mutant alleles causing abnormalities are inherited. Single nucleotide substitution results in incorrect amino acid. Results in a change in conformation of the b-globin protein when deoxygenated. Is a syndrome, conditions affect expression of the trait. Albinism missing enzyme in pathway to melanin production. Huntington disease mutation caused by extra nucleotide repeats cag in the gene. Cystic fibrosis mutations in a protein responsible for chloride ion regulation; accumulation of thick mucus in the lungs. Sequence repeats have high tendency for mutations because dna polymerase slips during. P,f1,f2 are not used in pedigrees, bc new individuals come into the pedigree that are not in the line of decent.
