Question

The two pure breeding white flowered varieties of sweet pea were crossed, the F${}_1$ hybrids were all purple-flowered plants. If F${}_1$ hybrids were selfed, what will be the ratio of purple and white flowered varieties were produced?

• A. 9:7
• B. 12:3:1
• C. 9:3:4
• D. None of the above

Answer 1

The correct option is A 9:7

Epistasis is the interaction at the phenotypic level of organization between two or more genes to control a single phenotype. The genes that are involved in a specific epistatic interaction show independent assortment at the genotypic level. But the phenotypic ratios deviate from those expected with independent assortment. Thus two true breeding white flowers in produce purple flowers in F${}_1$ generation. Thus the correct answer is option A.