12.4 Beyond Medelian Heredity I. Patterns of Heredity Can Be _________________ A. _________________Dominance 1. an individual displays a trait that is ___________________the two parents a. example- flower color in snapdragons, a cross between red and white flowers produces pink color B. _______________________ 1. two dominant alleles are expressed at the same time 2. _____________from incomplete dominance in that both traits are displayed a. example- roan hair color in horses, a cross between red and white hair results in a mix of both hair on the horse

C. ____________________Alleles 1. traits with more than two alleles a. example- human blood type – A, B, O 1. A & B are dominant over O 2. Neither is dominant over the other when both are present they are ______________ D. Sex-Linked Traits 1. determined by genes only found on ______chromosome 2. Sex linked disorders occur in men more than women a. ex.- being ________________

1. weather conditions can affect phenotype E. Environmental ___________________________ 1. weather conditions can affect phenotype a. the artic fox’s coat is red in summer and white in winter 1. the color pigments shut down due to the extreme cold. F. _______________________Inheritance 1. Polygenic characters a. when several genes affect a characteristic b. ex.- eye color 2. maybe on same chromosome or many ______________________________ 3. Linked – genes that are close together & help to determine the same trait