HMB265H1 Chapter Notes - Chapter 6: Hh Blood Group, Mendelian Inheritance, Epistasis

• School: UTSG
• Department: Human Biology
• Course: HMB265H1
• Professor: Maria Papaconstantinou

Document Summary

Hmb265 lecture 6 readings - extensions of mendelian genetics part 2 (pg. Mendel"s traits determined by allelic variations of single gene. Most traits from 2+ genes = polygenic traits. Two genes can interact to determine one trait. Genes can interact in several ways to determine single trait. Ex: lentils: tan x grey = 1 trait. F2: 9 brown, 3 tan, 3 grey, 1 green. Same ratio observed in f2 generation from dihybrid cross for 2 genes. When mendel saw 9331 ratio was for 2 genes for 2 unrelated traits. Now looking at same trait controlled by 2 genes. = combo of genotypes at 2 independently assorting genes interact produce seed colour. For 2 genes that determine seed coat colour need: Both dominant alleles to yield brown (a- b-) Dominant allele of one gene (a) to produce tan = (a- bb) Dominant allele of one gene (b) to produce grey = (aa b-) No dominant alleles to produce green (aa bb)