Biology 1001A Lecture Notes - Lecture 10: Enzyme, Probability Distribution, Mutation
18 Oct 2016
School
Department
Course
Professor
Document Summary
People used to believe that inheritance (cid:449)as (cid:862)(cid:271)le(cid:374)di(cid:374)g(cid:863) You were a blend of your mum and dad. Polygenic traits show continuous variation in a population. Mendel picked traits that were not continuous (no intermediates) Careful experimentation with controlled cross and quantitative analyses. Me(cid:374)del"s e(cid:454)peri(cid:373)e(cid:374)ts led to a(cid:374) e(cid:454)pla(cid:374)ator(cid:455) (cid:373)odel: Variation in traits due to different alleles. Organisms inherit 2 alleles for each trait. Appearance of heterozygotes determined by dominant alleles. The genes for sexual function are not exclusively on sex chromosomes. Whenever the progeny from a reciprocal cross is different, it probably results from sex- linkage. In class question: the allele l in drosophila is recessive, sex-linked and lethal. If a heterozygous female was mated to a normal male, what fraction of the offspring would die: 0, 1. Alleles of two genes assort independently in dihybrid crosses. 9: r_ y_, 3: r_ yy, 3: rr y_, 1: rr yy.
