Doggy Extra Credit

For this extra credit problem we are asked to determine the genotype of the father of these pups based off of the mother and pup's phenotypes.  So first we look at the mom and see that she is yellow and therefore recessive for color (bb) and dominant for melanin production (Mm) or (MM).  Knowing this we must look at the pups and see that some of them come out dominant for color; aka some are black and some are brown (Bb) and (BB).  This means that the father must have had to be homozygous dominant (BB).  This means for the lighter ones there had to be recessive melanin.  In other words there had to be at least one recessive melanin gene from the mom and dad.  Therefore the dad of these pups must be BBMm and the mom is bbMm.