In rats, gene b produces black coat color if the genotype is b–, but black pigment is not produced if the genotype is bb. at an independent locus, gene d produces yellow pigment if the genotype is d–, but no pigment is produced when the genotype is dd. production of both pigments results in brown coat color. if neither pigment is produced, coat color is cream. a third independently assorting gene involved in determination of coat color in rats is the c gene. at this locus, the genotype c– permits expression of pigment from genes b and d. the cc genotype, however, prevents expression of coat color and results in albino rats.
(a)-determine the genotypes of parents that produce the following progeny: 27/64 brown; 16/64 albino; 9/64yellow; 9/64 black; 3/64 cream.
(b)-determine the genotypes of parents that produce the following progeny: 9/16 brown; 3/16 black; 4/16albino.
(c)-determine the genotypes of parents that produce the following progeny: 3/8 black; 3/8 cream; 2/8albino.
(d)-determine the genotypes of parents that produce the following progeny: 3/4 brown; 1/4 yellow