Final answer:
When a white blood cell encounters a new bacteria, it undergoes phagocytosis to engulf and destroy the bacteria.
Step-by-step explanation:
When a white blood cell encounters a new bacteria, it recognizes it as foreign to the body. The white blood cell then undergoes phagocytosis, which is the process of engulfing and destroying the bacteria. This helps to eliminate the bacteria and prevent the spread of infection.
For example, neutrophils are a type of phagocyte that specifically attack pathogens and dead cells. They surround the bacteria and destroy them through phagocytosis.
Other white blood cells, such as macrophages, can also perform phagocytosis and play a role in eliminating bacteria from infected tissues.