Question

John and Pat are identical twins with identical DNA. John works in a movie theater, and Pat works as a lifeguard. They have very different skin pigmentation. Which is the best explanation of the difference?

Answer 1

The answer is:

A) Skin color, a polygenic trait, is also determined by environmental factors.

Hope it helps!

Answer 2

The best explanation of the difference is Skin color, a polygenic trait, is also determined by environmental factors.
Environmental factors can greatly impact somebody's skin and its pigmentation. In this case, the presence of sunlight is the environmental factor - one of the boys works in a movie theater, with little to no exposure to the Sun, whereas the other one spends most of his days in sunlight, which is why his skin color is different from his brother's.