Final answer:
Apoptosis is the process of programmed cell death triggered by external signals. It plays a crucial role in various biological processes, including T-cell development.
Step-by-step explanation:
Apoptosis is the process of programmed cell death that occurs in response to various signals. It is a complex event that involves signal transduction, where external signals are received by the cell to initiate the apoptosis mechanism. External signaling can trigger apoptosis in various circumstances, such as when a cell is damaged, potentially dangerous, or uncontrolled cell division occurs. For example, in T-cell development, immature T-cells undergo screening to determine whether they bind to self proteins. If the T-cell receptor binds to self proteins, the cell initiates apoptosis to remove the potentially dangerous cell.
Learn more about Apoptosis