Question

The phenotypic ratio obtained in the $F_2$ generation of a monohybrid cross in dog flower plant is ___.

• A. 1:2:1
• B. 3:1
• C. 1:1
• D. 2:1

Answer 1

The correct option is A

1:2:1

Dog flower plant (Antirrhinum majus) or snapdragon shows incomplete dominance. In the cross of red and white flowering snapdragon- all the $F_1$ offspring had pink flowers, indicating that neither red nor white flower color was dominant. Heterozygotes are thus intermediate in color. Further when two of the $F_1$ pink flowers were crossed, they produced red, pink, and white-flowered plants in a 1:2:1 ratio in the $F_2$ generation.