WJEC Biology Practice Exam

Phagocytes are a type of white blood cell specifically equipped to identify, engulf, and destroy pathogens such as bacteria and viruses. Their primary function is to perform phagocytosis, a process where a cell surrounds and takes in harmful particles. Once a pathogen is engulfed, phagocytes break it down using enzymes, thereby protecting the body from infection. This is a crucial aspect of the innate immune response, as phagocytes act quickly to eliminate potential threats.

While plasma cells, lymphocytes, and T-cells also play important roles in the immune system, they are not the primary cells responsible for directly engulfing and destroying pathogens. Plasma cells produce antibodies that help target pathogens, lymphocytes, including B-cells and T-cells, are more involved in the adaptive immune response, which is specific and requires a previous encounter with the pathogen for activation. T-cells assist in the immune response but do not perform phagocytosis. Thus, phagocytes are the most relevant type of white blood cell when discussing the direct action of engulfing and eliminating pathogens.