Question

Mendel first crossed pure-bred pea plants having round -yellow seeds with pure-bred pea plants having wrinkled -green seeds and found that only round- yellow seeds were produced in the $F_1$ generation. When $F_1$ generation pea plants having round-yellow seeds were cross-bred by self-pollination, then peas having round-yellow seeds, round green seeds, wrinkled-yellow seeds and wrinkled -green seeds were produced. Mendel collected a total of 2160 seeds.

(a) What will be the number of
(i) round green seeds
(ii) wrinkled green seeds
(iii) round yellow seeds, and
(iv) wrinkled-yellow seeds?

Answer 1

Mendel’s observed dihybrid ratio for $F_2$ progeny as $9:3:3:1.$

(i) Number of round green seeds $=\frac{3}{16}\times 2160=405.$

(ii)  Number of wrinkled green seeds $=\frac{1}{16}\times 2160=135.$

(iii)  Number of round yellow seeds $=\frac{9}{16}\times 2160=1215.$

(iv) Number of wrinkled yellow seeds $=\frac{3}{16}\times 2160=405.$