What is the soft, spongy tissue in the center of most bones that contains red marrow and yellow marrow?

• A. Cartilage
• B. Adipose Tissue
• C. Bone Marrow
• D. Synovium

Answer: (C)

The main idea here is identifying the tissue that fills the center of most bones: bone marrow. It’s a soft, spongy substance inside the bone’s central cavity where two types reside. Red marrow is hematopoietic, meaning it makes blood cells, while yellow marrow stores fat. In children, red marrow is more widespread; in adults, it’s mainly in certain bones, with yellow marrow more common in the long-bone cavities. The other options refer to different tissues: cartilage sits at joint surfaces and cushions movement; adipose tissue is fat tissue throughout the body, not the marrow inside bones; and the synovium lines joints and produces synovial fluid.