Which leukocyte is not considered a phagocyte?

Lymphocytes are not considered phagocytes, which is the reason they are the correct choice in this context. Phagocytes are specialized cells that engulf and digest foreign particles, pathogens, and cellular debris through a process called phagocytosis. The main types of phagocytes include monocytes and neutrophils.

Monocytes circulate in the bloodstream and migrate into tissues where they differentiate into macrophages, the principal phagocytic cells in the immune system. Neutrophils are the most abundant type of white blood cell and are among the first responders to infection or inflammation, effectively performing phagocytosis to eliminate pathogens.

Eosinophils, while primarily involved in combating parasitic infections and contributing to allergic responses, can also perform phagocytosis to some extent, although this is not their primary function. In contrast, lymphocytes, which include T cells and B cells, are mainly involved in the adaptive immune response, providing targeted immunity rather than directly engaging in phagocytosis. Therefore, lymphocytes do not align with the role of phagocytes, making them the correct answer to the question.