Work Step by Step
To get this answer, do a Punnett square for each gene on its own-- for example, flower color is Ppxpp. Find the probabilities for each genotype for each gene. Then, write out the possible overall genotypes with at least two homozygous recessive genes: ppyyIi, ppYyii, Ppyyii, ppYYii, ppyyii. Calculate the probability for each of those using the individual gene Punnet square results. For example, for ppyyii, it's 1/2 for pp, 1/4 for yy, and 1/2 for ii, which you multiply to get 1/16. Add the probabilities for each of the five listed genotypes: 1/16, 2/16, 1/16, 1/16, 1/16 = 6/16 = 3/8.