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. From the results given above, determine the mode of inheritance by assigning gene symbols and indicating which genotypes yield which phenotypes.

Key Concepts

Modes of Inheritance

Modes of inheritance describe how traits are passed from parents to offspring. Common modes include autosomal dominant, autosomal recessive, and incomplete dominance. Understanding these modes is crucial for predicting phenotypic outcomes based on genotypes, especially in cases where traits do not breed true, as seen with palominos.

Genotype and Phenotype

Genotype refers to the genetic makeup of an organism, while phenotype is the observable expression of that genotype. In the context of horse color, specific genotypes will lead to distinct phenotypes, such as cremello, chestnut, and palomino. Recognizing the relationship between these two concepts is essential for determining inheritance patterns.

Incomplete Dominance

Incomplete dominance occurs when neither allele is completely dominant over the other, resulting in a phenotype that is a blend of both traits. In the case of palominos, this suggests that their phenotype arises from a combination of alleles that do not produce a consistent genotype, leading to variability in offspring. This concept is key to understanding why palominos do not breed true.