Genotypic Ratio Definition

Pattern of genotype-based offspring distribution (i.e. the genetic makeup of an organism that determines its phenotype.)

After a test cross, the genotypic ratio represents the number of times a genotype appears in the progeny. For example, a heterozygous dominant trait test cross between two organisms with the same genotype, Rr, will produce offspring with the genotypes RR, Rr, and rr. The expected genotypic ratio in this case is 1:2:1.