What is the phenotypic ratio of a dihybrid cross between two double heterozygotes (independent assortment)?
Answer and explanation
Correct answer: C. 9 : 3 : 3 : 1
- Step 1: AaBb × AaBb gives nine A–B–, three A–bb, three aaB– and one aabb. Answer: 9 : 3 : 3 : 1. Why not the others: 3 : 1, 1 : 1 : 1 : 1 and 1 : 2 : 1 don't fit.
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