During the warm temperatures of summer, the arctic fox produces enzymes that cause its fur to become reddish-brown. During the cold temperatures of winter, these enzymes do not function. As a result, the fox has a white coat that blends into the snowy background. What explains this change in color?
the genes of a fox are made of unstable DNA
mutations can be caused by temperature extremes
random alteration of DNA can occur on certain chromosomes
the expression of certain genes is affected by temperature