BIOL 265 Lecture 6: Sex Determination and Sex Linked Characteristics (Part 3); Extensions and Modifications of Mendelian Principles of Inheritance (Part 1)

• School: UBC Okanagan, UBC OK
• Department: Biology
• Course: BIOL 265
• Professor: Brendan D' Souza

Document Summary

A1 = red, a2 = white (no pigment: incomplete dominance: Genotype ratio - 1 pp: 2 pp: 1pp. Phenotype ratio 1 purple: 2 violet: 1 white: each of the 3 genotypes corresponds to a distinct phenotype, codominance: heterozygote simultaneously expresses phenotype of both homozygotes, ex. Mn blood type: possible alleles at mn locus - lm allele (encodes m antigen) and ln allele (encodes n antigen) Lmlm homozygotes express m antigen (m blood type) Lnln homozygotes express n antigen (n blood type) Lmln heterozygotes express both m and n antigen (mn blood type: type of dominance of a characteristic depends on a level at which phenotype examined, ex. Cystic fibrosis: defect (gene mutation) in cftr protein (cytisc fibrosis transmembrane conductance regulator) Lecture 6: normal cftr allele (normal cftr protein) : genotype does not always produce the expected phenotype: ex. human polydactyly extra fingers and toes.