In the common daisy, genes A and B control flower color. Both genes have a dominant allele (A or B) and a recessive allele (a or b) . At least one copy of each dominant allele is required for flowers to be colorful instead of white.
-Predict the phenotypic ratio of the F₂ progeny of a cross between two white-flowered plants, one homozygous for A and the other homozygous for B.

Question

Quizplus · Accepted Answer

The cross involves two white-flowered plants, one with genotype AAbb and the other aaBB. The F1 generation will all be AaBb (colorful). The F2 generation will have a 9:7 ratio of colorful (A-B-) to white (aa-- or --bb) due to the requirement of at least one dominant allele from each gene for color.

In the Common Daisy, Genes a and B Control Flower