Final answer:
Mendel studied a large number of pea plants to accurately apply the laws of probability and predict offspring traits. The garden pea's true-breeding nature, observable traits, and quick maturation made it an ideal model for inheritance studies.
Step-by-step explanation:
It was important for Gregor Mendel to study a large sample of pea plants to determine the probability of inheritance because small sample sizes might not accurately reflect the patterns of inheritance due to random chance. By examining large numbers of pea plants, Mendel was able to obtain results that closely matched the expected ratios dictated by the laws of probability. This rigorous approach enabled him to predict the traits of offspring based on known parental traits, laying the foundation for what we now understand as genetics.
One reason why the garden pea was an exceptional model system for studying inheritance is that they are true-breeding, which means they consistently produce offspring with the same traits as the parent when self-fertilized. This provided Mendel with a clear and predictable pattern of inheritance to study. Additionally, the pea plants displayed easily observable traits, grew to maturity in one season, and were simple to cross-fertilize, which enabled Mendel to conduct experiments over several generations in a relatively short timeframe.