I took a quiz in my AP Bio class and I do not understand how my answer was wrong and how the "correct" answer was right. Two dogs, each heterozygous for two traits (Ff Tt) reproduced and made two separate litters of puppies. The question gives 4 phenotypic ratios and asks which one is most likely to be present in the two litters. Two are obviously wrong, so I'll leave those out. In a dihybrid cross, we know that the ratio is 9:3:3:1. The "correct" answer gives litter 1 a 10:3:3:1 ratio and litter 2 a 9:3:4:0 ratio. The answer I chose simply follows the expected ratio of 9:3:3:1 for both litters. I am well aware that it does not happen often for things to come out exactly 9:3:3:1 in a dihybrid cross. However, I do not believe that the two ratios given in the "correct" answer are any more likely than recieving a perfect ratio, since the puppies would have to come in the exact numbers and traits that the answer choice says. Can anybody help me see why that answer is correct, or possibly if I am correct in my argument? All help is appreciated.