AI Tutor
Imagine taking every single piece of a bicycle—the pedals, the chain, the wheels, and the handlebars—and piling them in a heap on your driveway.
Does that pile get you to school? Of course not, because the pieces are only useful when they connect and work together.

What Makes a System?

A system is a group of related parts that move matter, transfer energy, or share information to do a job as one combined whole.
Each smaller group of parts inside that bigger system is called a subsystem, like the steering setup or the brake gear on your bike.
When parts rely directly on each other so that one part cannot do its job without the others, scientists call this functional interdependence.
Back in the 1930s, biologist Ludwig von Bertalanffy pointed out that you can never truly understand an object or creature just by looking at its separate pieces in isolation.
A bicycle is a mechanical system made by humans—so what happens when we look inside a living creature?

Biological Systems in Living Bodies

Your own body is a living biological system built from interacting subsystems called organ systems.
Consider two key subsystems: your respiratory system (lungs and airways) and your circulatory system (heart and blood vessels).