Horses can be cremello (a light cream color), chestnut (a brownish color), or palomino (a golden color with white in the horse's tail and mane). Of these phenotypes, only palominos never breed true. Predict the F₁ and F₂ results of many initial matings between cremello and chestnut horses.

Key Concepts

Incomplete Dominance

Incomplete dominance occurs when the phenotype of heterozygotes is intermediate between the phenotypes of the two homozygotes. In the case of horse coat colors, a cremello (homozygous for a cream allele) crossed with a chestnut (homozygous for a brown allele) may produce offspring that exhibit a blend of these traits, leading to a distinct phenotype in the F₁ generation.

Punnett Square

A Punnett square is a diagram used to predict the genotypes of offspring from a genetic cross. By setting up a Punnett square for the cremello and chestnut horses, one can visualize the potential combinations of alleles in the F₁ generation, helping to determine the expected ratios of phenotypes and genotypes in the offspring.

F₁ and F₂ Generations

The F₁ generation refers to the first filial generation of offspring resulting from a cross between two parental (P) genotypes. The F₂ generation is produced by interbreeding the F₁ individuals. Analyzing the F₁ and F₂ generations allows for understanding inheritance patterns, including the ratios of different phenotypes and the potential for traits to segregate in subsequent generations.