Under What Conditions Does One Expect A 9 3 3 1 Ratio? The Correct Answer Is Dihybrid

Question

Under what conditions does one expect a 9:3:3:1 ratio? The correct answer is dihybrid

cross (F2) with independent assorting, completely dominant genes.

My answer was a dihybrid test cross (F2) with independently, completely dominant genes assorting…..why is my answer wrong?

Thanks.

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