question_answer 39)

  Bone matrix is rich in (a) fluoride and calcium                                                 (b) calcium and phosphorus (c) calcium and potassium                                            (d) phosphorus and potassium

Answer:

  (b) Bone cells are embedded in a hard matrix, which is strengthened by fibers, and hardened by calcium and phosphorus salts. The matrix is deposited in form of concentric layers of lamellae formed around a central Aversion canal,                 The bone cells occupy small spaces between the concentric layers of matrix.