Final answer:
The composite structure that includes parts of both the axial and appendicular skeletons are the pectoral and pelvic girdles.
Step-by-step explanation:
The composite structure that includes portions of both the axial and appendicular skeletons is the pectoral and pelvic girdles. The pectoral girdle, consisting of the clavicle and scapula, connects the upper limbs to the axial skeleton. Similarly, the pelvic girdle connects the lower limbs to the vertebral column.
The axial skeleton forms the central axis of the body, including the skull, vertebral column, and thoracic cage. The appendicular skeleton is composed of the bones of the upper and lower limbs, in addition to the girdles that attach them to the axial skeleton.
Notable components of the appendicular skeleton are the arm, forearm, hand, thigh, leg, and foot bones, as well as the bones of the hands and feet.