What is the soft, spongy tissue inside bones where blood cells are produced?

• A. Bone marrow
• B. Platelets
• C. Spongy tissue
• D. Lymph nodes

Answer: (A)

Blood cell production happens in bone marrow, the soft, sponge-like tissue inside bones. This tissue contains stem cells that differentiate into red blood cells, white blood cells, and platelets—through a process called hematopoiesis. In adults, red marrow is found in certain bones and at the ends of long bones, while yellow marrow mainly stores fat and isn’t involved in making blood cells. Lymph nodes are immune organs that filter lymph, not sites of blood cell creation, and platelets are products of hematopoiesis produced in the marrow, not the production site itself. So the soft, spongy tissue inside bones where blood cells are produced is bone marrow.