Final answer:
The garden pea was an excellent model for studying inheritance due to its distinct and contrasting phenotypic traits, ability to self-pollinate or be cross-pollinated, short generation time, and large offspring numbers, which enabled clear observation of dominant/recessive patterns and ample data for Mendel's genetic experiments.
Step-by-step explanation:
One of the reasons the garden pea (Pisum sativum) was an excellent choice of model system for studying inheritance is because of its clear and distinct phenotypic traits. Gregor Mendel chose pea plants with contrasting traits such as seed texture, seed color, and flower color. For instance, he observed the characteristics of flower color to be either white or violet, which are controlled by a single gene with two alleles. Mendel used pure-breeding pea plants in his experiments, which ensured that the offspring would inherit a clear dominant or recessive trait, leading to predictable patterns in the first-generation offspring (F1) and the subsequent generation (F2).
Mendel's findings, such as the 9:3:3:1 phenotypic ratio seen in dihybrid crosses between smooth yellow and green wrinkled peas, indicated a pattern of dominant/recessive inheritance. These observable patterns allowed Mendel to develop the foundational principles of heredity without knowledge of the underlying genetic mechanisms, which were not discovered until later.
The plant's ability to self-pollinate or to be easily cross-pollinated also made it simpler to control mating. This, combined with its short generation time and the production of large numbers of offspring, allowed Mendel to conduct many controlled genetic experiments and collect statistically significant data. Hence, the garden pea became a cornerstone in the understanding of genetic inheritance.