Question

Which of the bones of the axial skeleton listed below is paired?

A) fifth thoracic vertebra
B) rib 3
C) the sacrum
D) the sphenoid

Answer 1

Among the listed bones, Rib 3 is the only paired bone in the axial skeleton, with one rib on each side of the body. The correct option is B.

Step-by-step explanation:

The question asks which of the bones listed is paired in the axial skeleton. Among the options provided:

• The fifth thoracic vertebra is part of the vertebral column and is not paired as each vertebra is a single bone in the column.
• Rib 3 is a paired bone since there are two third ribs in the thoracic cage, one on each side of the body.
• The sacrum is a single bone formed by the fusion of five sacral vertebrae.
• The sphenoid is a single, unpaired bone of the skull.

Therefore, the answer is Rib 3, which is a paired bone in the axial skeleton.