Final answer:
The skeletal system, specifically the bone marrow, is responsible for the production of blood cells through the process of hematopoiesis, which includes the generation of various blood cell types such as granulocytes, a type of leukocyte.
Step-by-step explanation:
The system that produces blood cells is known as the skeletal system. In particular, blood cell production occurs in the bone marrow, a process called hematopoiesis. The bones provide not only a structural framework for the body but also house the bone marrow, where red blood cells, white blood cells, and platelets are generated.
Within the bone marrow, hematopoietic stem cells differentiate into various types of blood cells, including granulocytes, which are a type of leukocyte or white blood cell.