Of the following: Hematopoiesis, Red marrow, Yellow marrow, Spongy bone, which does not belong?
The words 'yellow marrow' are odd in the list.
These terms all deal with bone anatomy and physiology.
This is a diagram of the structure of a typical human long bone. Spongy bone is found on the two ends of the long bone. The thin crisscrossing plates of bone (shown in white) are called trabeculae.
The spaces within spongy bone are filled with red marrow (shown in red).
Red bone marrow is responsible for hematopoiesis, a fancy name for blood cell formation. There are other spongy bones like vertebrae, girdles, etc., which are also engaged in hematopoiesis.
While the two ends of a long bone consist mainly of spongy bone, the shaft consists of compact bone. Inside the shaft of compact bone is a marrow cavity filled with yellow marrow, which stores fat.
In conclusion, the pores of spongy bone contain red bone marrow, which function in hematopoiesis. These terms all relate to the production of blood cells. Yellow marrow, however, consists mainly of fat cells.