Example: Coat color in laboradors black pigment is dominant to brown B b pigment deposition in hair is dominant to no deposition, so hair is yellow. E e Genotype Phenotype EEBB Black EeBB EEBb EeBb EEbb Brown Eebb eeBB yellow eeBb eebb Example. Cross two Black labs that are heterozygous for both coat color genes. What are the expected phenotypic ratios?? Genes and Environment The phenotype of an individual does not result from its genotype alone. Genotype and environment interact to determine the phenotype. Two terms you need to understand (page154): Penetrance whether it is always expressed – Expressivity how it is expressed or the degree it is expressed – Linked genes Some do not sort independently. They are said to be linked.
Example: Coat color in laboradors B black pigment is dominant to b brown E pigment deposition in hair is dominant to e no deposition, so hair is yellow. Genotype Phenotype EEBB Black EeBB EEBb EeBb EEbb Brown Eebb eeBB yellow eeBb eebb Example. Cross two Black labs that are heterozygous for both coat color genes. What are the expected phenotypic ratios?? Genes and Environment The phenotype of an individual does not result from its genotype alone. Genotype and environment interact to determine the phenotype. Two terms you need to understand (page154): Penetrance – whether it is always expressed Expressivity – how it is expressed or the degree it is expressed Linked genes Some do not sort independently. They are said to be linked.
Chapter%208%20Notes%202015%20AP%20Genetics.docx