Consider the following genetic study involving two autosomal genes. One of these, eye colour, has the dominant allele (R) for red eye colour and the recessive allele (r) for yellow eye colour. The other has the dominant allele (T) leading to paws with thumbs, while the recessive allele (t) codes for paws without thumbs. Presuming no linkage between the genes, what should be the phenotype ratio of the offspring produced by a testcross (RrTt × rrtt)?

Question

Quizplus · Accepted Answer

In a testcross involving RrTt and rrtt parents, the offspring will exhibit a 1:1:1:1 phenotypic ratio because each trait segregates independently, resulting in four possible combinations: red-eyed with thumbs, yellow-eyed with thumbs, red-eyed without thumbs, and yellow-eyed without thumbs.

Consider the Following Genetic Study Involving Two Autosomal Genes