In a unique species of plants, flowers may be yellow, blue, red, or mauve. All colors may be true breeding. If plants with blue flowers are crossed to red-flowered plants, all F₁ plants have yellow flowers. When these produced an F₂ generation, the following ratio was observed: 9/16 yellow: 3/16 blue: 3/16 red: 1/16 mauve In still another cross using true-breeding parents, yellow-flowered plants are crossed with mauve-flowered plants. Again, all F₁ plants had yellow flowers and the F₂ showed a 9:3:3:1 ratio, as just shown. Describe the inheritance of flower color by defining gene symbols and designating which genotypes give rise to each of the four phenotypes.