Final answer:
White blood cells (WBCs) are divided into granulocytes (neutrophils, eosinophils, basophils) and agranulocytes (lymphocytes, monocytes), each with distinct functions in the immune system. Granulocytes respond to infections, combat parasites, and partake in allergic responses, while agranulocytes are involved in immune response, antibody production, and phagocytosis.
Step-by-step explanation:
White Blood Cells and Their Functions
White blood cells (WBCs), or leukocytes, play a crucial role in the body's immune system. Granulocytes and agranulocytes are the two main categories of WBCs. Granulocytes, which contain visible granules in their cytoplasm, include neutrophils, eosinophils, and basophils. Neutrophils are the most abundant WBCs and are first responders to microbial infection. Eosinophils combat multicellular parasites and certain infections in vertebrates. Basophils are involved in allergic reactions and inflammation.
Agranulocytes do not contain granules and include lymphocytes and monocytes. Lymphocytes are pivotal in the body's immune response and are divided into B-cells and T-cells. B-cells produce antibodies, while T-cells destroy infected host cells and activate other immune cells. Monocytes, which are the largest type of WBCs, differentiate into macrophages and dendritic cells in tissue and are responsible for phagocytosing pathogens and dead cells.
To determine the relative percentages of different WBCs, one must be able to distinguish between these cell types by their morphology after histologic staining as observed under a microscope.