What are mature red blood cells produced by the bone marrow called?

Mature red blood cells produced by the bone marrow are called erythrocytes. These cells are vital for the body's function as they are responsible for carrying oxygen from the lungs to tissues throughout the body and returning carbon dioxide from the tissues back to the lungs. The term "erythrocyte" specifically refers to these red blood cells, which contain hemoglobin, the protein that binds oxygen.

Erythrocytes are produced through a process known as erythropoiesis in the bone marrow, where hematopoietic stem cells differentiate and mature into red blood cells. This process is crucial, as the human body constantly requires a fresh supply of red blood cells to maintain adequate oxygen levels.

The other options refer to different types of blood cells: leukocytes are white blood cells involved in the immune response, thrombocytes are platelets that play a key role in blood clotting, and plasma cells are mature B lymphocytes that produce antibodies. Each of these cells has distinct functions that are essential to the overall health and functionality of the biological system, but they are not involved in oxygen transport like erythrocytes.