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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?
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Solution
(1) Number of round green seeds = `2160/16 xx 3 = 405`
(2) Number of wrinkled green seeds = `2160/16 xx 1 = 135 `
(3) Number of round yellow seeds = `2160/16 xx 9 = 1215 `
(4) Number of wrinkled yellow seeds = `2160/16 xx 3 = 405 `
b) The dihybrid ratio (which is 9: 3: 3: 1) has been used to answer part (a).
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