Final answer:
The arm is the body part that acts as a lever.
Step-by-step explanation:
In the human body, bones and joints function as levers. A lever is a simple mechanical device consisting of a rigid bar (bone), a fixed point or fulcrum (joint), and a force applied at some distance from the fulcrum. The arrangement of these components determines the type of lever and its mechanical advantages in performing different movements.
The body part that acts as a lever is the arm. Just like a handle on a hammer, the arm can apply force to move objects or perform actions. The muscles and bones in the arm work together to create the necessary leverage for movement.