Here's a breakdown of how these levels relate:

* Cells: The basic unit of life.

* Tissues: Groups of similar cells that work together to perform a specific function (e.g., muscle tissue, nervous tissue).

* Organs: Structures made up of different tissues that work together for a common purpose (e.g., heart, lungs, stomach).

* Organ Systems: Groups of organs that work together to carry out major bodily functions (e.g., circulatory system, digestive system).

* Organism: A complete living being made up of multiple organ systems working together.