The traits which Mendel studied in pea plant reason being that allele which produces wrinkled peas which are being recessive and their offspring of cross will also have peas which are wrinkled.
The other traits which Mendel studied in pea plants include flower color, seed shape, seed coat tint, pod shape, plant height and flower location.
Mendel studied pea plant reason being that Mendel had traits which were easily observed and were good manipulated.