Question

which of the following bones is classified as \irregular\ in shape?
frontal
metatarsal
ulna
patella
vertebra

Explanation:

Bones are classified into different types based on shape. The frontal bone is a flat bone, metatarsal is a long bone, ulna is a long bone, patella is a sesamoid bone. Vertebrae have complex and non - standard shapes, thus are classified as irregular bones.

Answer:

vertebra