Horses have three base coat color red (or chestnut), bay, and black. All the colors are controlled by the interaction of two genes, Extension
(E) and Agout (A). The following combinations produce bay color EE/Aa Ee/Aa, EE/AA, Ee/An Only two produce black color EE/aa, Ea/aa.
Other combinations of the alleles of these qenes plus mutations of othera result in many possible coat colors and patterns in horses
Coat color in horses is an example of which type of inheritance?
dominant inheritance
Orocessive inheritance
Mendelian inheritance
polygenie inheritance
The Correct Answer and Explanation is :
Coat color in horses is an example of Mendelian inheritance.
Explanation:
Mendelian inheritance describes the way genes and their alleles interact to determine specific traits, based on the principles Gregor Mendel established with his experiments on pea plants. In the case of horse coat color, we see Mendelian inheritance in action because the coat color is determined by combinations of alleles for two main genes: Extension (E) and Agouti (A).
- The Extension (E) gene determines whether a horse can produce black pigment. Horses with at least one dominant E allele (EE or Ee) have the ability to produce black pigment, which is essential for either bay or black coat colors. If a horse has two recessive alleles (ee), it results in a red (or chestnut) coat because the horse cannot produce black pigment.
- The Agouti (A) gene determines the distribution of the black pigment. If a horse has a dominant A allele (AA or Aa), it restricts the black pigment to specific areas of the body, resulting in a bay coat. If the horse has two recessive alleles (aa), the black pigment is not restricted and appears throughout the coat, producing a black horse.
Thus, the interaction between these two genes, with their dominant and recessive alleles, follows Mendelian principles of inheritance. The Extension gene controls pigment production, while the Agouti gene controls the pigment’s placement. This results in predictable outcomes for coat color based on allele combinations.
While additional mutations and other genes can affect variations and patterns, the fundamental mechanism behind the three base coat colors—red, bay, and black—is Mendelian. These base coat colors are established through simple dominance and recessiveness interactions typical of Mendelian inheritance, rather than being influenced by multiple interacting genes as in polygenic inheritance.