Biology STAAR (State of Texas Assessments of Academic Readiness) Practice Test

What does the appendicular skeleton consist of?

1. The bones of the skull and vertebral column

2. The bones of the ribcage and sternum

3. The bones of the arms and legs

4. The bones of the pelvis only

The correct answer is: The bones of the arms and legs

The appendicular skeleton is primarily responsible for facilitating movement and mobility, as it includes the bones that form the limbs and their attachments to the axial skeleton. This comprises the bones in the arms (including the humerus, radius, and ulna) and legs (including the femur, tibia, and fibula), as well as the girdles that connect these limbs to the central structure of the body—specifically, the shoulder girdle (clavicles and scapulae) for the arms and the pelvic girdle (pelvis) for the legs. This layout allows for a wide range of movements and is essential for actions such as walking, running, and grasping. In contrast, the skull and vertebral column, the ribcage and sternum, and the pelvis only do not encompass the full scope of the appendicular skeleton, as they are either part of the axial skeleton or a limited subset of bones.