In pea plants, the gene for round seed (r) is dominant, and wrinkled seeds (r) are recessive. the endosperm of the pea is also either starchy, a dominant gene (s), or waxy (s). what cannot be said of a cross between two parents that are heterozygous for both traits?

None is wrinkled and waxy

Explanation:

Spliting the alleles and pairing them usng the two characters listed, The male pea plant will have four possible alleles: RS, Rs, rS, and rs. The female also we have the same. Using punnet's square, we are to cross the two parents, Using gentotypes obtained from this cross; RRSS, RRSs, RrSS, RrSs, RRSs, RRss, RrSs, Rrss, RrSS, RrSc, rrSS, rrSs, RrSs, Rrss, rrSs, rrss. The phenotupic ration will be 9 Round starchy: 3 Round waxy: 3 Wrinkled starchy: 1 wrinkled waxy. It cannot be said that none of the progeny will be wrinkled waxy.