Final answer:
Phagocytes discriminate between apoptotic and viable cells by recognizing specific signals on the surface of apoptotic cells. These signals are not present on viable cells. Receptors on phagocytes bind to these apoptotic signals, triggering their engulfment and clearance. One example is the recognition of abnormal cells by natural killer cells, which induce apoptosis to eliminate infected or tumor cells.
Step-by-step explanation:
Phagocytes discriminate between apoptotic and viable cells through various mechanisms. One key mechanism is the recognition of specific signals on the surface of apoptotic cells, such as exposure of phosphatidylserine. In contrast, viable cells do not display these signals. Phagocytes have receptors that bind to these apoptotic cell signals, triggering their engulfment and clearance. For example, natural killer (NK) cells recognize abnormal cells, bind to them, and release molecules that induce apoptosis. This process helps eliminate infected or tumor cells.