Basic life activities include organization, metabolism, reaction, mobility, and reproduction.
There are additional requirements in humans, who represent the most sophisticated form of life, such as growth, differentiation, breathing, digestion, and excretion.
All of these events are linked together.
Organs and organ systems provide distinct roles in the human body.
The stomach, for example, is responsible for food storage as well as combining and breaking down food so that it can be further processed.
The kidneys, likewise, filter and eliminate metabolic wastes from the body.