01:119:115 Lecture Notes - Lecture 18: Family Tree Dna, Cystic Fibrosis, Lethal Allele
2 May 2016
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Document Summary
Difficulties in studying human genetics: few offspring, long generation span (20-30 years, cant do experimental mating btw individuals unethical and illegal. Instead analyze results of mating that have already occurred. Dna sequencing identify order of nucleotides: pedigree analysis. Pedigree= family tree shows inheritance patterns within a family over several generations. Predict inheritance of phenotypic traits that are controlled by genotype at single locus. Recessive allele codes for malfunctioning protein or no protein at all. Heterozygote recessive have disease 2 copies of gene usually born from carrier parents: albinism. Autosomal recessive disorder lack of pigmentation in skin and hair: cystic fibrosis. Cystic fibrosis= most common lethal genetic disease in the us. Recessive allele defective or absent chloride transport channels in plasma membranes. Lead to buildup of cl- ions outside the cell. Symptoms mucus buildup in internal organs: sickle-cell disease. Caused by the substitution of a single aa in hemoglobin protein in rbcs.
