Dear student,
Law of Independent Assortment by Mendel
When two pairs of traits are combined in a hybrid, one pair of character segregates independently of the other pair of character. In a dihybrid cross between two plants having round yellow (RRYY) and wrinkled green seeds (rryy), four types of gametes (RY, Ry, rY, ry) are produced. Each of these segregates independent of each other, each having a frequency of 25% of the total gametes produced.
This is how Mendel explained the law of independent assortment.
Regards