Final answer:
Before Mendel's research, the blending theory of inheritance was prevalent, which proposed that offspring were a mix of their parents' traits. Mendel's experiments with pea plants showed distinct inheritance patterns, challenging this belief and leading to the development of modern genetics.
Step-by-step explanation:
Prior to the groundbreaking work of Johann Gregor Mendel, the dominant belief regarding plant hybrids was based on the blending theory of inheritance. This theory posited that offspring would exhibit a mixture of their parents' traits, resulting in blended characteristics.
For example, it was expected that a tall and a short plant would produce medium height offspring. Mendel's observations in his garden led him to question this theory, as he saw examples such as tall and short plants producing offspring that were either tall or short, not intermediate.
Mendel conducted experiments with pea plants to investigate these inheritance patterns further. Through his monohybrid crosses, he discovered that some traits, such as pod color and seed shape, were inherited in distinct patterns rather than blending.
His work demonstrated that traits are transmitted faithfully from parents to offspring, often showing a dominant and recessive pattern. This contradicted the blending inheritance theory and eventually led to the understanding of genetics that we have today.