Levels of Organization

Atoms

smallest unit of matter

Molecules

Groups of two or more atoms held together by chemical bonds

Organelles

A tiny cell structure that carries out a specific function within the cell

Cells

The basic unit of structure and function in all living things

Tissues

Groups of cells with a common structure and function.

Organs

Groups of tissues that work together to perform a specific function

Organ System

A group of organs that work together in performing vital body functions.

Organism

A living thing