Final answer:
When Mendel crossed plants with contrasting traits, the dominant trait appeared in all F1 offspring while the recessive trait reemerged in 1/4 of the F2 offspring, showing a 3:1 ratio. His findings laid the groundwork for understanding heredity.
Step-by-step explanation:
When Mendel crossed plants with contrasting characters for the same trait, such as crossing purple flowered-plants with white flowered-plants, he observed that the offspring did not show a blending of traits. Instead, in the first generation (F1), all offspring exhibited the dominant trait; in the case of flower color, they were all purple. However, when these F1 plants were allowed to self-fertilize, the recessive trait reappeared in the second generation (F2). Mendel recorded that 75% of the F2 plants had the dominant purple flowers, while 25% exhibited the recessive white flowers, this resulted in a ratio of approximately 3:1 for the dominant vs. recessive trait.
Mendel's experiments demonstrated the principles of heredity and the segregation of traits. His work with thousands of pea plants revealed that characteristics such as seed color, plant height, and others were inherited independently of each other, which led to the formulation of Mendel's laws of inheritance. These results were crucial in developing the foundation for modern genetics.