Apoptosis

Apoptosis, also known as programmed cell death, is a term in physiology for the death of cells occurring normally in multicellular organisms. The average adult human loses between 50 and 70 billion cells each day due to apoptosis while in an average human child between the ages of 8 to 14 years it is around 20 to 30 billion. The phenomenon is a kind of control of an organism's growth.