In mice, black color (b) is dominant to white (b). at a different locus, a dominant allele (a) produces a band of yellow just below the tip of each hair in mice with black fur. this gives a frosted appearance known as agouti. expression of the recessive allele (a) results in a solid coat color. if mice that are heterozygous at both loci are crossed, what is the expected phenotypic ratio of their offspring? a. huntington's diseaseb. tay-sachs diseasec. phenylketonuriad. cystic fibrosise. sickle-cell disease