Final answer:
Mendel chose to study pea plants because of their easily observable characteristics, short life cycle, and large number of offspring. These traits make pea plants an excellent choice for genetic studies.
Step-by-step explanation:
Mendel chose to study pea plants because they have easily observable characteristics, a short life cycle, and produce a large number of offspring. Pea plants have visible traits such as seed form and color, flower color, pod form and color, placement of pods and flowers on stems, and stem length. These traits make it easier to study and analyze genetics. Furthermore, pea plants grow quickly and can be cultivated in large quantities, allowing for numerous experiments to be conducted in a short period of time.