In a dihybrid cross of two heterozygous individuals, you expect a 9:3:3:1 phenotypic ratio in the offspring, but observe a ratio of 9:7. What is the most likely explantation?
A)Codominance
B)It is a sex-limited trait
C)Simple Mendelian inheritance
D)Incomplete penetrance
E) Epistatic interaction of the two genes

Question

Quizplus · Accepted Answer

An epistatic interaction of the two genes is the most likely explanation for a deviation from the expected phenotypic ratio in a dihybrid cross. This occurs when the expression of one gene masks or modifies the expression of the other gene. In this case, one or both of the genes may be interacting in a way that leads to the observed 9:7 ratio instead of the expected 9:3:3:1 ratio.

In a Dihybrid Cross of Two Heterozygous Individuals, You Expect