In pea plants, the allele for purple flowers (P) is dominant and the allele for white flowers (p) is recessive. The allele for yellow seeds (Y) is dominant and the allele for green seeds (y) is recessive. The allele for round seeds (R) is dominant and the allele for wrinkled seeds (r) is recessive. These alleles segregate independently of each other. A plant with a PpYyRr genotype is crossed with a plant with a PpyyRr genotype. What is the probability that an offspring from this cross has at least two different recessive traits

The answer would be c, white eyes are homozygous recessive. in the early 1900s, morgan conducted several experiments with vinegar  flies (drosophila). one  sample revealed an anomaly: a  white-eyed, single male fly. he attempted to breed this fly with the typical red-eyed females. the offspring were all red-eyed. using flies from this new generation (brother-sister pairs)  produced some red-eyed and a few white-eyed flies. the white-eyed were all male. in later experiments, he was able to produce white-eyed females. this proved that white eyes are not lethal to either sex (ruling out a and b). since the percentage of white eyes to red eyes is so low, white eyes are not a dominant trait. it would be a recessive trait.