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 F₁ generation. When F₁generation 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?

Answer 1

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

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

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

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

b) The dihybrid ratio (which is 9: 3: 3: 1) has been used to answer part (a).