Bateson and Punnett crossed two white- flowered lines and saw all purple flowers in the F1 generat They concluded this was an example of complementary gene interactions because a cross of the F1 plants yielded what ratio in the F2 generation?
A) 16 purple to 0 white
B) 7 purple to 9 white
C) 0 purple to 16 white
D) 9 purple to 7 white
E) 8 purple to 8 white

Question

Quizplus · Accepted Answer

The correct answer is D) 9 purple to 7 white. This is because in complementary gene interactions, two different genes work together to produce a phenotype. If an organism is homozygous recessive for either gene, it will not display the dominant phenotype. In this case, purple flowers are produced only when both genes are present in at least one dominant form (A_B_). The F2 generation from a dihybrid cross in such a scenario typically shows a phenotypic ratio of 9:7 (9 showing the dominant phenotype and 7 showing the recessive phenotype), indicating complementary gene interaction.

Bateson and Punnett Crossed Two White- Flowered Lines and Saw