Question

9. In guinea pigs, rough coat is dominant (R) to smooth coat (r) and black coat (B) is dominant to white coat (b). A rough black guinea pig bred with a rough white one produces 29 rough black offspring, 31 rough white offspring, 11 smooth black and 9 smooth white. Give the genotypes of the parents, the probability for the offspring, and the actual number of each kind of offspring you would expect. ________ Genotype of the rough, black parent

Answer 1

Answer:

the genotype of the parent guinea pigs are as follows:

RrBb (rough, black) and Rrbb (rough, white)

Explanation:

Since the phenotype of smooth coat is present in the offspring, the parent genotype cannot have RR alleles for their coat. Similarly, the rough, black parent cannot have BB alleles in its genotype because that will not yield a white coat color in its offspring.

After making the dihybdrid cross, the probability obtained for each phenotype is given below:

rough black: $\frac{3}{8}$

rough white: $\frac{3}{8}$

smooth black: $\frac{1}{8}$

smooth white: $\frac{1}{8}$

Hope that answers the question, have a great day!