What did mendell hypothesize about first generation plants?

Mendel hypothesized that first-generation plants, when crossed, would display a dominant trait in their offspring. He observed that when he crossed purebred plants with contrasting traits, such as tall and short pea plants, the resulting first-generation (F1) plants exhibited only the dominant trait. This led him to propose the concept of dominance in inheritance, suggesting that some traits mask the expression of others in the presence of a dominant allele.