L48 Anthro 150A Lecture Notes - Lecture 4: Mendelian Inheritance, Pleiotropy, Y Chromosome
Document Summary
Law of segregation: every trait is determined by two alleles, one from the mother and one from the father. Law of independent assortment: one gene locus does not affect another. Dominant allele: masks the other allele at a given gene locus. Recessive allele: is masked by the dominant allele and only is expressed in the phenotype when paired with another recessive allele. ***natural selection acts on phenotypes, but affects the genotype of the next generation. Codominance: both alleles contribute to the phenotype: ex. Post mendelian genetics (exceptions to mendel"s rules: 1. Not all genes are inherited in two compliments: ex. Mitochondrial dna is only from the mother: ex. Genes on the y chromosome do not mirror those on the x chromosome. Some genes are pleiotropic: pleiotropic: when one gene affects not just one, but several traits. The genes that determine skin color also affect eye color: 3. Most traits are polygenic: polygenic: multiple genes govern a single trait.
