Gene C controls fur pigmentation in Himalayan rabbits, which are pictured below. The rabbit on the left has pigmentation on its ears, nose, and feet, where it loses most of its body heat. The rabbit on the right has no fur pigmentation. What is the best explanation for this difference in pigmentation? a Higher temperatures cause genes to mutate during development. b Environment affects the expression of the genes for that trait. c The genes for dark fur color and light fur color are located on different chromosomes. d The type of genes present in the rabbits are related to the surrounding environment.

Answer 1

The best explanation for the difference in pigmentation observed in Himalayan rabbits, where one rabbit has pigmentation on its extremities and the other has none, is b) Environment affects the expression of the genes for that trait.

In Himalayan rabbits, the gene responsible for fur pigmentation is temperature-sensitive. The gene is expressed differently depending on the temperature; cooler areas of the rabbit's body (like the ears, nose, and feet) allow for pigment production, while warmer areas (like the body) do not. This is a classic example of how environmental factors can influence gene expression.