Describe the traits that make Pisum sativum an ideal organism for genetic studies. This pea has distinct, heritable features in the form of dichotomous phenotypes that can be easily observed and quantified. It can be self-crossed to generate true-breeding plants. This pea has a distinct, modifiable feature in the form of a single dominant trait that can be easily observed. It can be self-crossed to generate reciprocal plants. This pea has distinct, modifiable features in the form of dichotomous phenotypes that can be easily observed and quantified. It can be self-crossed to generate dominant plants. This pea has distinct, heritable features in the form of a single recessive trait that can be easily observed. It can be self-crossed to generate recessive plants.