ANT202H5 Lecture Notes - Lecture 3: Mns Antigen System, Gregor Mendel, Mendelian Inheritance
Document Summary
Father of modern genetics: mendel + darwin = modern synthesis of evolution, mendel"s law of segregation, mendel"s law of independent assortment, work rediscovered in 1900. Mendel"s experiments: crossed different purebred pea plants. Wanted to test the idea of blended inheritance: phenotype - observed appearance of a trait in an organism. Mendel"s law of segregation: genotype = genetic endowment of organism from 2 alleles present at given locus. Offspring inherited one unit from each parent: allele: one member of a gene pair that codes for different versions of a trait, allele combinations. Homozygous = both alleles at given locus identical. 3:1 smooth:wrinkled: dominant - allele that masks effect of other in heterozygous genotype. Always phenotypically expressed: recessive - allele whose effect is masked by other in heterozygous genotype. Expressed only in homozygous form: combo of 2 different alleles = 4 phenotypic outcomes, dominance - heterozygote same phenotype as one of the homozygotes.
