Give reasons for the appearance of new combinations of characters in the F2 progeny.

1. Soln:

The appearance of new combinations in the F2 generation can be explained through the law of independent assortment, according to which when two traits are combined in a hybrid, one pair of character segregates independent of the other pair of characters. The two genes segregate independently at the time of gamete formation and recombine at the time of fertilisation to produce zygote with combinations different from parents as well.

E.g. when a tall pea plant with round seeds is crossed with a short plant with wrinkled seeds, we get all tall plants with round seeds in the F1 generation, because tallness and round seeds are dominant characters. When these plants are self-pollinated, we get new combinations in F2 progeny along with the parental combinations. The gene controlling the height and seed shape segregate independently and recombine to produce new combinations other than the parental combinations, i.e. tall plants with wrinkled seeds and short plants with round seeds. Therefore, we can concl