Mendel’s experiments show that traits are inherited independently by the dihybrid cross experiment. In this experiment, he took two traits seed shape and seed colour. The yellow colour (YY) was dominant over the green colour (yy), while the round shape (RR) is dominant over the wrinkle shape (rr). In F2 generation of dihybrid cross, he got the phenotypic ratio of 9:3:3:1. In this ratio, 9 plants with round yellow (RRYY) seeds, 3 plants with round green (RRyy) seeds and 3 plants with wrinkled yellow (rrYY) seeds and one with wrinkled green seeds (rryy). From this result, it was observed that when two pairs of traits were crossed, each trait expressed independent of the other. Thus, Mendel proposed the Law of Independent Assortment which says that traits are inherited independently.