Which of the following ratios represents the modified dihybrid ratio when one gene locus exhibits codominance?

Understand the Problem

The question is asking which ratio represents the modified dihybrid ratio when one gene locus shows codominance. This involves understanding Mendelian genetics and the patterns of inheritance.

More Information

In a case where one gene displays codominance, each allelic combination creates a distinctly observable phenotype. As a result, the typical dihybrid Mendelian phenotype ratio of 9:3:3:1 is split further according to combinatorial phenotypes, yielding a 1:2:1:2:4:2:1:2:1 ratio.

Tips

A common mistake is to misinterpret codominance as incomplete dominance, where phenotypic expression changes significantly.

Sources

• Incomplete dominance, codominance & multiple alleles (article) - khanacademy.org