Two highly inbred tobacco plants are crossed. One has dark green leaves. The other has yellow leaves. The F₁ have light green leaves. Five hundred progeny from F₁ × F₁ crosses are analyzed. Their leaves show continuous variation in color, but none has dark green or yellow leaves. What do these data suggest about the number of genes determining this trait?

Question

Quizplus · Accepted Answer

The continuous variation in leaf color and the absence of the parental phenotypes (dark green or yellow) in the F2 generation suggest that multiple genes are involved, likely more than four, contributing to a polygenic inheritance pattern.

Two Highly Inbred Tobacco Plants Are Crossed