So you want to be an intelligence analyst. Students occasionally write to me and ask for advice on getting a job in the Intelligence Community. (I became an intelligence analyst at DIA after undergrad. I was there for about three years, and after that, I did a few years of consulting for various intel agencies.) The below is a gist of that advice. It is heavily biased by my own experience, and none of the below is meant to be universal.
Apoptosis, or programmed cell death, is a naturally occurring process in the body. It involves a controlled sequence of steps in which cells signal self termination. Apoptosis works to keep the body's natural cell division process of mitosis in check.
There are three mechanisms that cause cell death: Self-generated signals in a cell, which may arise from age, infection, irregular mitosis (cell division), or other causes. This mechanism is known as the intrinsic or mitochondrial pathway, whereas the following two types of cell death are extrinsic pathways.