Which two bone marrow types differ in function, with one producing blood and the other storing fat?

• A. White marrow and Brown marrow
• B. Red marrow and Yellow marrow
• C. Blue marrow and Green marrow
• D. Black marrow and White marrow

Answer: (B)

Bone marrow comes in two functionally distinct forms: one is responsible for making blood, while the other mainly stores fat. Red marrow contains hematopoietic tissue with stem cells that continuously produce red blood cells, white blood cells, and platelets. Yellow marrow is rich in adipocytes and serves as a fat storage site, being largely inactive in blood cell production under normal conditions. This difference in activity explains why one type is the blood-forming component and the other acts as an energy reserve. In adults, red marrow is mainly in the flat bones and the ends of long bones, while yellow marrow fills the medullary cavities of the long bones. If needed, yellow marrow can convert back to red marrow to boost blood cell production during severe anemia or blood loss.