Assume that in guinea pigs, the brown coat color allele (b) is dominant over red (b), and the solid color allele (s) is dominant over spotted (s). the f1 offspring of a cross between true-breeding brown, solid-colored guinea pigs and red, spotted guinea pigs are crossed. what proportion of their offspring (f2 generation) would be expected to be red and solid-colored?

The proportion of the offspring (F2) would be expected to be red and solid colored is 3/16 because in a dihybrid cross a 9/16 are dominant for both traits, 3/16 is dominant for one and recessive for the other, 3/16 are reverse and 3/16 are recessive for both. Finding the fraction that is red which is recessive and solid which dominant, therefore the answer will be 3/16.