Bone is composed of
A) living cells that secrete a surrounding matrix.
B) a hard composite of phosphate and sodium ions.
C) channels containing lymphoid tissue.
D) hardened cartilage.

Question

Quizplus · Accepted Answer

Bone is composed of living cells called osteoblasts and osteocytes, which secrete and maintain a mineralized matrix of calcium and phosphate. This matrix gives bone its strength and hardness. Therefore, option A is the best choice. Option B is partly correct as bone does contain phosphate ions, but it is not composed solely of them. Option C is incorrect as bone does not contain lymphoid tissue. Option D is incorrect as bone is not hardened cartilage, although both tissues are related to each other in development.

Bone Is Composed of