Which type of white blood cells are known to contain granules?

Granulocytes are a specific type of white blood cell characterized by the presence of granules in their cytoplasm. These granules contain various enzymes and proteins that are crucial for the immune response, particularly in fighting off infections and inflammatory processes. Granulocytes can be further classified into three main types based on their staining properties: neutrophils, eosinophils, and basophils. Each of these types plays a distinct role in the body's defense system, with neutrophils primarily acting in bacterial infections, eosinophils dealing with parasitic infections and allergic reactions, and basophils contributing to inflammatory responses and allergic reactions.

The other choices pertain to different types of blood cells. Lymphocytes, for example, do not contain granules and are primarily involved in the adaptive immune response. Monocytes are larger white blood cells that also do not have granules; they differentiate into macrophages and dendritic cells to help eliminate pathogens. Thrombocytes, or platelets, are not a type of white blood cell at all, but rather play a key role in blood clotting.

Thus, granulocytes are the only type of white blood cells in the question that have the defining feature of granules in their cytoplasm.