Genetics of Skin and Eye Color

The video explains that traits like height, weight, eye color, and skin color are polygenic, meaning they are controlled by multiple genes. This results in a wide variety of phenotypes, such as different shades of eye and skin color. Melanin, a pigment, plays a crucial role in these variations. The video also discusses how multiple genes contribute to the diversity in skin and eye color, with biologists suggesting at least three genes for skin color and two or three for eye color. Additionally, it touches on how infants' eye color can change as they start producing melanin.

Which of the following is an example of a polygenic trait?

• Cystic fibrosis

• Sickle cell anemia

• Height

• Blood type

What is the primary reason for the wide range of eye colors in humans?

• Dietary influences

• Multiple genes controlling eye color

• Environmental factors

• Single gene inheritance

What pigment is responsible for the color of skin and eyes?

• Hemoglobin

• Melanin

• Carotene

• Chlorophyll

If melanin production were controlled by a single gene, what would be the expected skin color of an individual with two recessive alleles?

• Medium skin tone

• Olive skin

• White skin

• Dark skin

How many incompletely dominant genes are believed to control skin color?

• Four

• Three

• Two

• One

What is the result of having three different genes controlling skin color?

• Infinite shades of skin

• Only two shades of skin

• Seven different shades of skin

• No variation in skin color

How many genes are believed to control eye color?

• Four

• Two or three

• One

• Five

Why do some infants' eye colors change as they grow older?

• Delayed melanin production

• Exposure to sunlight

• Change in diet

• Genetic mutation

What would be the result if only one gene controlled eye color?

• Only three different eye colors

• Infinite eye colors

• No eye color variation

• A wide variety of eye colors

Which of the following is NOT a factor in determining eye color?

• Melanin production

• Genetic inheritance

• Dietary habits

• Number of genes involved