Final answer:
Apoptosis is the process of programmed cell death crucial for tissue development and homeostasis, involved in processes like the separation of digits during embryonic development and the maturation of the immune system.
Step-by-step explanation:
The process that refers to programmed cell death, which is essential for tissue development and homeostasis, is known as apoptosis. This process is crucial during various stages of life, such as embryonic development and the maturation of the immune system. For example, during vertebrate development, the cells forming web-like tissue between fingers and toes are eliminated via apoptosis to allow for the proper separation of these digits. Similarly, during the development of T-cells, a type of immune cell, those that bind to 'self' proteins are triggered to undergo apoptosis to prevent autoimmune diseases. The control and execution of apoptosis involve a series of molecular events, including the release of cytochrome C from the mitochondria, which is a crucial step in this programmed cell death pathway.