Natural selection is affected by (variations, competitions), or traits that are different in members of the same species.

Match each description with the correct form of energy. 1. energy of an object's position above the ground. 2. stored in the bonds of atoms and molecules 3. stored in the nucleus of an atom 4. energy of vibrating molecules 5. movement of objects used to do work 6. created by vibrations in electric and magnetic fields chemical energy mechanical energy heat gravitational energy light nuclear energy