Progressive retinal atrophy (PRA) is a genetic condition fou…

Progressive retinal atrophy (PRA) is a genetic condition found in certain dog breeds; its is particularly prevalent in Entlebucher Mountain Dogs.  PRA  is characterized by the bilateral degeneration of the retina (in the eye) causing progressive vision loss culminating in blindness. The condition  is inherited as an autosomal recessive trait.   Two Entlebucher Mountain Dogs, both carriers, have a pup with PRA.  What is the probability that their next two pups will not have PRA?

von Willebrand’s disease (vWD) is a blood clotting disorder…

von Willebrand’s disease (vWD) is a blood clotting disorder in standard poodles. A defect in the gene that encodes the the von Willebrand factor (a blood clotting protein) is responsible for the vWD phenotype in homozygous (ww) individuals.  W is the dominant allele and w is the recessive allele because the W allele