Which bone does not belong to the appendicular skeleton

Subject : Biology

Question:

Which bone does not belong to the appendicular skeleton?

A. Sacrum

B. Femur

C. Calcaneus

D. Clavicle

E. Ulna

Expert Verified Solution:

The correct answer is A. Sacrum. The sacrum is part of the axial skeleton, not the appendicular skeleton. It is a triangular-shaped bone located at the base of the spine and forms part of the pelvis, connecting the spine to the hip bones (ilium).

Here’s a breakdown of the bones listed:

Femur (B): The thigh bone, part of the appendicular skeleton.
Calcaneus (C): The heel bone, part of the appendicular skeleton.
Clavicle (D): The collarbone, part of the appendicular skeleton.
Ulna (E): A forearm bone, part of the appendicular skeleton.

The appendicular skeleton includes the bones of the limbs and those that attach the limbs to the axial skeleton (which includes the skull, spine, and rib cage). The sacrum, being part of the spine, belongs to the axial skeleton.