Microbiology Practice Exam 2026 - Free Microbiology Practice Questions and Study Guide

The correct answer is monocyte, as these immune cells are precursors to macrophages. Monocytes circulate in the bloodstream and, upon entering tissues, they differentiate into macrophages or dendritic cells. This transformation is crucial because macrophages play a vital role in the immune response; they are responsible for phagocytosing pathogens, presenting antigens to T cells, and secreting various cytokines that help regulate inflammation and immune responses.

Neutrophils, while important for the body's defense against infections, do not mature into macrophages; they are typically short-lived cells that respond rapidly to sites of infection. Eosinophils primarily deal with parasitic infections and play a role in allergic reactions, but they do not convert to macrophages either. Basophils are involved in inflammatory responses and allergic reactions, releasing histamine, but they also do not mature into macrophages. Understanding the unique roles and developmental pathways of these immune cells is essential in the study of immunology and microbiology.