Here's a breakdown:
* Cells: The basic building blocks of life.
* Tissues: Groups of similar cells that work together to perform a specific function (e.g., muscle tissue, nervous tissue).
* Organs: Groups of different tissues that work together to perform a more complex function (e.g., the heart, the lungs, the stomach).
* Organ Systems: Groups of organs that work together to carry out major bodily functions (e.g., the digestive system, the circulatory system).
Think of it like this:
* Cells are like bricks.
* Tissues are like walls built from bricks.
* Organs are like rooms built from walls.
* Organ Systems are like a whole house built from rooms.
