In a complete dominance monohybrid cross between a pure breeding yellow-flowered plant Y and a pure breeding white-flowered plant y, the result of the first...

In a complete dominance monohybrid cross between a pure breeding yellow-flowered plant Y and a pure breeding white-flowered plant y, the result of the first filial generation is 100% yellow flowers. This is because yellow flower color is dominant over white flower color, and the Y allele is dominant over the y allele. As a result, all the offspring in the first generation, also known as the F1 generation, will have one Y allele from the yellow-flowered parent and one y allele from the white-flowered parent, making them all yellow-flowered heterozygotes. However, if we cross the F1 generation plants with each other, we will get a 3:1 ratio of yellow to white flowers in the second filial generation (F2), because the yellow-flowered heterozygotes can produce both yellow and white-flowered offspring.