Beyond Mendelian Inheritance When black + white = black, white, gray or spots Incomplete dominance or blended dominance Codominance Multiple Alleles Regulatory Genes

Incomplete Dominance When the resulting phenotype is a blend of a heterozygous allele pair: red flower + blue flower = purple flower The allele for red flower would be F R and the allele for blue flower would be F B. Can you complete the genotypes and phenotypes on your paper? GenotypePhenotype FRFRFRFR Red Flowers FBFBFBFB Blue Flowers FRFBFRFB Purple Flowers

Codominance When the resulting phenotype shows both traits of an allele pair: red flower + blue flower = red and blue spotted flowers The allele for red flowers would be R. The allele for blue flowers would be B. Can you complete the genotypes and phenotypes on your paper? GenotypePhenotype RRRed Flowers BBBlue Flowers RBRed and blue spotted flowers

Multiple Alleles When there are more than 2 variations. EX: Human blood types have 3 different alleles, A, B, and O. GenotypesPhenotypes AA, AOA blood type ABAB blood type BB, BOB blood type OOO blood type

Regulatory Genes Regulate the expression of other genes. It may “silence” another gene from expressing its dominant trait. EX: Manx cats have no tails because there is a gene that “silences” the gene for a tail. The tail silencing gene has the possible alleles: S – “silences” tail = no tail s – doesn’t “silence” tail = tail Question: Can Manx cats without tails have a kitten with a tail? Show your answer with a Punnett Square.

Cat tails? Question: Can 2 Manx cats without tails have a kitten with a tail? Show your answer with a Punnett Square. S = no tail s = tail Only if both parents are heterozygous.