A Level Biology Practice Exam

What is the role of phagocytes in the immune system?

1. Transport nutrients to cells

2. Produce antibodies

3. Engulf and digest harmful cells

4. Stimulate cell division

The correct answer is: Engulf and digest harmful cells

Phagocytes play a crucial role in the immune system by engulfing and digesting harmful cells, such as bacteria and other pathogens, a process known as phagocytosis. This is an essential mechanism for the body to protect itself against infections and maintain overall health. Once a phagocyte encounters a harmful cell, it surrounds and engulfs it within a vesicle. Enzymes within the phagocyte then break down the engulfed material, effectively neutralizing the threat. This function is vital for both the innate immune response, which is the body's immediate and general response to pathogens, and the adaptive immune response, which involves more specialized immune components to target specific pathogens. By removing dangerous invaders, phagocytes not only help eliminate infections but also play a role in alerting other immune cells to the presence of threats, thus coordinating a more robust immune response when necessary.