Bone marrow produces which of the following?

• A. Spongy bone
• B. Calcium and phosphorus
• C. Peritoneum
• D. Blood cells

Answer: (D)

Bone marrow is where hematopoiesis happens, the process of forming blood cells. In red marrow, hematopoietic stem cells differentiate into the various lineages that become red blood cells, a wide array of white blood cells, and platelets. These cells are essential for oxygen transport, immune defense, and clotting. That’s why the marrow’s primary function is to produce blood cells. Spongy bone is a type of bone tissue formed by trabeculae; calcium and phosphorus are minerals stored in bone; the peritoneum is the lining of the abdominal cavity. The marrow’s role is specifically the production of blood cells, with red marrow doing most of this work and yellow marrow mainly storing fat.