Final answer:
The mandible operates as a class III lever, with the fulcrum at the temporomandibular joint, the effort from the masseter muscle during contraction, and the load being the resistance experienced while biting and chewing.
Step-by-step explanation:
The mandible acts as a class III lever in the human skeletal system. This classification is due to the position of the masseter muscle, which is one of the strongest muscles in our body and is responsible for elevating the mandible to close the mouth, primarily during the process of mastication, or chewing. In a class III lever, the fulcrum is at one end, the effort is applied between the fulcrum and the load, and the load is at the opposite end. For the jaw, the fulcrum is the temporomandibular joint, the effort is the contraction of the masseter muscle, and the load is the resistance during biting and chewing.