Intermediate phenotype in heterozygotes… It is a “blend” between the dominant and recessive forms of the gene
Sample Problem In horses, the dominant D allele allows coat color to fully develop. The d allele dilutes, or weakens, coat color. When a chestnut (brown) horse is crossed with a cremello (nearly white) horse, their offspring are palominos (gold with white manes and tails)
Sample Problem Continued What is the genotype of… A chestnut horse? ______________ A cremello horse? ______________ A palomino horse? ______________ What would be the expected phenotypic ratios of a cross between two palomino horses?
Sample Problem Achondroplasia, a form of dwarfism, is caused by the dominant allele A. Embryos with the genotype AA do not survive. Suppose that two people with achondroplasia get married and have children. What phenotypic ratio would you observe in the couple’s children?