Question

Give reasons for the appearance of new combinations of characters in $F_2$ progeny.

Answer 1

The reason for the appearance of new combinations in the $F_2$ generation is given by the law of independent assortment. The law of independent assortment states that:

When two pairs of traits are combined in a hybrid, one pair of character segregates independent 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 are produced (RY, Ry, rY, ry). Each of these segregate independent of each other, each having a frequency of 25% of the total gametes produced.