Explain Mendel's dihybrid cross.

Explanation

It is a cross between two plants differing in 2 pairs of contrasting characters.
Mendel selected the shape of the seed and colour of the cotyledons as the two pairs of contrasting characters. Round seed coat is dominant over wrinkled seed coat and yellow colour of cotyledon is dominant over the green colour.
Mendel crossed a pure breeding garden pea plant producing round and yellow seeds with a pure breeding garden pea plant producing wrinkled and green seeds.

Round seed coat and green cotyledons=3
Wrinkled seed coatand green cotyledons=1
Dihybrid phenotypic ratio=9:3:3:1
Genotypic ratio:1:2:2:4:1:2:1:2:1
Thus in the `F_(2)` generation, he got yellow round, yellow wrinkled, greenround and greenwrinkled inthe ration of 9:3:3:1,respectively.