True-breeder round and yellow-seeded pea plants were crossed with a true-breeder wrinkled and green-seeded pea plant to raise F₁ offspring. What is true for the F₁ generation of this cross? (Note: The allele "Y", which produces the yellow color of the seed in the pea plant, is completely dominant over "y", which makes the seed green. The allele for the round (R) shape is completely dominant over the wrinkled shape (r).