Veterinary Assistant Practice Exam 2025 - Free Veterinary Assistant Practice Questions and Study Guide

The primary function of white blood cells, also known as leukocytes, is to fight infections. These cells are a vital component of the immune system, tasked with identifying and eliminating pathogens such as bacteria, viruses, fungi, and parasites. They play a crucial role in the body's defense mechanism by recognizing foreign invaders and orchestrating an immune response.

Different types of white blood cells have specialized functions; for instance, neutrophils are rapid responders to infections, while lymphocytes (including T cells and B cells) are involved in adaptive immunity, providing long-lasting defense through memory and antibody production. The ability of white blood cells to track, attack, and destroy infectious agents is essential for maintaining health and preventing illness.

The other options relate to different functions of other components of blood: red blood cells are responsible for transporting oxygen, platelets are involved in clotting, and plasma carries nutrients. This distinguishes the unique and vital role that white blood cells play in the immune response.