Question

ILL FAN AND GIVE A MEDAL
When a male pig from a line of true-breeding (homozygous) black, solid-hooved pigs was crossed to a female from a breed (homozygous) of red, cloven-hooved pigs, their several progeny all looked alike with regard to color and hooves. These progeny were all mated to members of the same breed as their red, cloven-hooved mother pig. The offspring from this final cross were: 11 black, cloven-hooved; 8 black, solid-hooved; 14 red, cloven-hooved; and 10 red, solid-hooved. For each of these two genes (coat color and hoof type) determine which allele is the dominant one. Explai

Answer 1

Explain your reasoning. What were the phenotypes of the progeny produced by the first mating in this problem?

Answer 2

Let's look at the ratios expected of a true dom/rec system with only one allele, across two generations.

Parent A is D/D parent B is d/d

So, what we see is that if we cross our homozygous parents we get 100% heterozygous offspring. Then, if we do the back cross (crossing the heterozygous offspring with their homozygous parents), we see that if we back cross with a homozygous dominant, we have only the dominant trait being apparent. However, if we back cross with the homozygous recessive, we have 50% of the dominant trait and 50% of the recessive trait apparent. Now just extend that to your two gene system.