Question

In the dihybrid cross, the two parental genotypes are AABB and aabb. The genotype of all F${}_1$ plants is AaBb. What phenotype ratio will be observed in the F${}_2$ generation?

• A. 8:4:2:1
• B. 1:1:1:1
• C. 4:2:2:1
• D. 1:2:2:1
• E. 9:3:3:1

Answer 1

The correct option is E 9:3:3:1

In the dihybrid cross, the two parental genotypes are AABB and aabb. The genotype of all F1 plants is AaBb. When AaBb is selfed, the gametes formed are AB, Ab, aB and ab. The 16 offsprings are obtained and have the phenotypic ratio as 9:3:3:1 as shown in the image.

Thus, the correct answer is option '9:3:3:1'.