Complementary genes A – black colour and B – albino colour in case of genotype A_B_ are realized as agouti mouse.

Date: 2015-10-07; view: 630.

Complementary genes.

While one gene may make only one protein, and other gene may make other protein the effects of those proteins usually interact. Novel phenotypes often result from the interactions of two genes, as in the case of the comb in chickens. The single comb is produced only by the rrpp genotype. Rose comb (b) results from R_pp. (_ can be either R or r). Pea comb (c) results from rrP_. Walnut comb, a novel phenotype, is produced when the genotype has at least one dominant of each gene (R_P_).

The typical F2 ratios for complementary genes are 9:7, 9:6:1, and 9:3:3:1. The third ratio is different of Mendelian dihybrid F2 ratio, because the 3/16 and 3/16 of filial have traits that are different of ones of P2.