Overview The use of manipulatives in teaching mathematics has a long tradition and solid research history.
Red bone marrow is the active portion that produces red blood cells, while yellow bone marrow contains fat cells. In adults the red bone marrow is located in the flat bones, such as the upper hip bones, known as the pelvic girdle, and the sternum.
There are two types of bone marrow: Red, or hematopoietic Produces red blood cells, white blood cells and platelets Gets its red color from the hemoglobin in the erythroid cells Hematopoietic cells mature and migrate into sinusoids to enter the circulation when they are formed.