Mendel crossed true-breeding plants bearing yellow seeds with true-breeding plants bearing green seeds. He then crossed the offspring from that mating with each other (F₁ generation). What was the genotypic ratio among the offspring of the F₁ generation?

Question

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When Mendel crossed the true-breeding plants with yellow seeds (YY) with true-breeding plants with green seeds (yy), he produced offspring with the genotype Yy (heterozygous dominant). When he crossed these offspring with each other, the Punnett square would show a 1:2:1 genotypic ratio of AA:Aa:aa. However, since the yellow allele (Y) is dominant, both AA and Aa individuals would have yellow seeds, resulting in a 3:1 phenotypic ratio of yellow:green. Therefore, the genotypic ratio among the F₁ generation would be 25% aa, 50% Aa/aA, and 25% AA.

Mendel Crossed True-Breeding Plants Bearing Yellow Seeds with True-Breeding Plants