BIOL 117 Lecture Notes - Lecture 5: Light Skin, Hydrangea, Phenylketonuria
Document Summary
Multiple allelism: genes that have more than two alleles. Polymorphic: more than two phenotypes available in a population. Incomplete dominance: heterozygotes have an intermediate phenotype: ex. red+white owers = pink owers, expression overall is mixed. Codominance: both alleles are expressed: ex. Roan bulls have bw geneotype (giving it a reddish color: expression in different hairs, for example, are different. Percentage of recombinant offspring can be used to estimate the location of genes relative to one another: map units are a measure of the frequency of crossing over, ex. 10 map units = 10% of the time it crosses over at that location: be able to recognize crossing over and recombinant genes, and also be able to recognize a linkage when you see it. Pleiotrophy: some genes in uence many traits: ex. Coat color may affect health (ex. homozygous merle are often deaf and/or blind)
