Final answer:
Self-pollination of F1 generation plants results in an F2 generation with a 3:1 ratio of purple to white flowers, demonstrating that the white flower trait is recessive and reappears in the F2 generation.
Step-by-step explanation:
When the F1 generation plants are self-pollinated, you would expect the F2 generation to exhibit a mix of flower colors based on Mendelian genetics. All plants in the F1 generation had purple flowers, but after self-pollination, the F2 generation showed a 3:1 ratio of purple to white flowers. This observation suggests that the purple flower characteristic is dominant over the white flower characteristic. Therefore, for every three purple-flowered plants, there was approximately one white-flowered plant. This demonstrates that the white flower trait, while masked in the F1 generation, was not lost but simply recessive and reappeared in the F2 generation.