Horse Coat Color Genetics

The video explains the three base coat colors of horses: chestnut, black, and bay. It discusses the role of two genes, extension and agouti, in determining these colors. The extension gene controls the production of black and red pigments, while the agouti gene affects the distribution of black pigment. The video also covers the concept of horse points, which are areas where color can vary. Understanding these genetic factors helps in identifying horse coat colors.

What are the three base coat colors of horses?

• Chestnut, Black, Bay

• White, Grey, Roan

• Palomino, Dun, Grullo

• Pinto, Appaloosa, Buckskin

Which pigment is responsible for the red color in horses?

• Eumelanin

• Pheomelanin

• Carotene

• Melanin

What does the extension gene determine in horses?

• The size of the horse

• The base color of the coat

• The distribution of black pigment

• The length of the mane

Which allele of the extension gene is dominant?

• Lowercase e

• Uppercase E

• Lowercase a

• Uppercase A

What is the role of the agouti gene in horse coat colors?

• It determines the horse's height

• It affects the horse's temperament

• It restricts black pigment to the points

• It changes the horse's eye color

How does the agouti gene affect a horse with no black pigment?

• It has no effect

• It changes the horse's mane color

• It turns the horse white

• It makes the horse grey

What happens when both the extension and agouti genes are turned on?

• The horse is entirely black

• The horse is bay

• The horse is chestnut

• The horse is white

Which genotype results in a black horse?

• Extension off, Agouti on

• Extension on, Agouti off

• Extension on, Agouti on

• Extension off, Agouti off

What is the effect of the agouti gene on a chestnut horse?

• It changes the horse's mane color

• It turns the horse black

• It has no effect

• It makes the horse bay

Which combination of genes results in a bay horse?

• Extension off, Agouti off

• Extension on, Agouti on

• Extension off, Agouti on

• Extension on, Agouti off