A breeder crosses white dogs with black dogs. F1 generation were all black dogs. The progeny were crossed to produce a F2 generation of; 71 white dogs:249 blakc dogs.© BrainMass Inc. brainmass.com October 9, 2019, 11:23 pm ad1c9bdddf
Let us assume that the trait of coat color involves one gene with two alleles. Since mating a black dog with a white dog results in all black dogs we will assume that the black allele (B) is dominant to the white allele (b). The first mating would look like bb x BB yielding all black offsprings with a genotype Bb. The next cross would involve two Bb black ...
Several paragraph explaining how to use chi-squared to determine if results from a cross agrees with Mendel's Law of Segregation. Web references provided.