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 F1 generation. When F1 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? (b) Which 'ratio' as established by Mendel have you made use of in answering the part (a) above?
When Mendel crossed pure-bred pea plants having round-yellow seeds (RRYY) with pure-bred pea plants having wrinkled-green seeds (rryy), only round-yellow seeds (RrYy) were produced in the F1 generation.
When F1 generation pea plants allowed for self-pollination, then peas having round-yellow seeds (RY), round green seeds (Ry), wrinkled-yellow seeds (rY) and wrinkled-green seeds (ry) were produced.
Out of a total 2160 seeds,
(a) The number of
(i) round green seeds = (2160 X 3)/16 = 405.
(ii) wrinkled green seeds = (2160 X 1)/16 = 135.
(iii) round yellow seeds = (2160 X 9)/16 = 1215.
(iv) wrinkled-yellow seeds = (2160 X 3)/16 = 405.
(b) Dihybrid ratio which is 9:3:3:1, established by Mendel is used during answering the above question.