POWER CHECK A. Circle the letter of your answer. (15 points) 1. A round body that directs all the functions of a cell is a a. vacuole b. cytoplasm C. nucleus d. cell wall 2. A life process involved in keeping an organism healthy by releasing its trash a. reproduction b. food-getting C. waste removal d. energy usage 3. A creature's ability to move about in different ways is called a. mobility b. growth C. feeding d. hibernation 4. The way a living thing acts or responds to a stimulus is its a. energy level b. behavior C. defense d. movement​