Which statement is an example of a scientific theory? A. The amount that caffeine affects a person's heart rate differs based on
the person's age. B. The Earth is the third planet from the Sun and has one moon, which orbits the Earth. C. Hummingbirds do not like the color white because they visit other colored flowers more often. D. All living organisms are composed of one or more cells, which came from pre-existing cells.
Homologous structures have the same ancestry, but may no longer serve the same function. For example, the bones that make up human fingers were inherited from an ancestor that's shared by all mammals.
