The axial skeleton is made up of

Step 1: Analyze the question The question asks which bones make up the axial skeleton.

Step 2: Explain the concept The vertebrate skeleton has two main divisions:

• Axial skeleton: the central axis of the body. It supports and protects the head, neck, and trunk. It includes the skull, the vertebral column (spine), the ribs, and the sternum (breastbone).
• Appendicular skeleton: the bones of the limbs (fore and hind) and the girdles (pectoral and pelvic) that attach the limbs to the axial skeleton.

Step 3: Evaluate the options

• A. Fore and hind limbs: appendicular, so wrong.
• B. Limbs and limb girdles: both are appendicular, so wrong.
• C. Ribs and sternum: these are part of the axial skeleton, but they are only a portion of it and leave out the skull and spine. This is incomplete.
• D. Skull and limbs: the limbs are appendicular, so wrong.
• E. Skull and spine: both are core parts of the axial skeleton. This is the best answer.

Step 4: Answer Option E is correct. Option C is also true as far as it goes, since ribs and sternum belong to the axial skeleton. However, E names the two main components (skull and vertebral column), so it is the best choice.

Exam tip: Think "axis = the central line of the body": head, backbone, and rib cage. Anything that hangs off the body (arms, legs, and the girdles that attach them) is appendicular. "Appendage" means something attached.