Which of the following best describes how horse coat color is determined?

• A. It is controlled by the interaction of multiple genes, each contributing to the final phenotype.
• B. It is controlled by mitochondrial DNA inheritance.
• C. It is solely influenced by environmental factors and not by genetics.
• D. It is determined by a single gene with two alleles showing complete dominance.

Answer: (A)

Verified step by step guidance

1. Understand that horse coat color is a classic example of a trait influenced by genetics, where multiple genes can interact to produce a variety of phenotypes.
2. Recall that mitochondrial DNA inheritance typically affects traits related to energy production and is passed maternally, but it does not usually determine coat color.
3. Recognize that environmental factors can influence some traits, but coat color in horses is primarily genetically determined rather than solely by the environment.
4. Consider the concept of single-gene inheritance with complete dominance, which would result in a limited number of phenotypes, unlike the diverse coat colors seen in horses.
5. Conclude that the best description is that horse coat color is controlled by the interaction of multiple genes, each contributing to the final phenotype, which explains the wide variety of coat colors observed.