Question: what are the two major functions of leukocytes?
Answer: The two main types of leukocytes are granulocytes and mononuclear leukocytes (agranulocytes). Leukocytes arise from hemopoietic stem cells in the bone marrow. Leukocytes are involved in pathogen recognition, phagocytosis (ingestion of particles), pathogen destruction, inflammation mediation, and antigen presentation.