Final answer:
The key difference between the pectoral girdle and the pelvic girdle is that the pelvic girdle is more secure and better able to bear weight, while the pectoral girdle is more mobile and flexible.
Step-by-step explanation:
The key difference between the pectoral girdle and the pelvic girdle is that the pelvic girdle is more secure and better able to bear weight, while the pectoral girdle is more mobile and flexible.
The pelvic girdle, which attaches the lower limbs to the torso, is securely attached to the axial skeleton through strong ligaments and has deep sockets that securely attach to the femur. This allows it to bear the weight of the body and facilitate locomotion.
In contrast, the pectoral girdle is not joined to each other, allowing each side to operate independently. The clavicle of each pectoral girdle is anchored to the axial skeleton by a highly mobile joint, enabling extensive mobility and flexibility, and enhancing movements of the shoulder and upper limb.