AP BIOLOGY

Detailed explanation-1: -Apoptosis, or programmed cell death, is a growth-limiting regulatory mechanism by which cells can trigger their own death in response to extracellular signals because of irreparable cellular or DNA damage. The ability of tumor cells to elude apoptosis is a hallmark of most types of cancer.

Detailed explanation-2: -Apoptosis is the process of programmed cell death. It is used during early development to eliminate unwanted cells; for example, those between the fingers of a developing hand. In adults, apoptosis is used to rid the body of cells that have been damaged beyond repair. Apoptosis also plays a role in preventing cancer.

Detailed explanation-3: -Apoptosis induced by many chemical genotoxins is the consequence of blockage of DNA replication, which leads to collapse of replication forks and DSB formation. These DSBs are thought to be crucial downstream apoptosis-triggering lesions.

Detailed explanation-4: -Apoptosis is important in the immune system, and plays significant roles in the control of the immune response, the deletion of immune cells recognising self-antigens, and cytotoxic killing. Some of the molecular regulators of these processes, such as CD95 and bcl-2 family proteins are the subjects of intense research.