1. Organization of Life

2. Atom
Smallest unit of matter

3. Molecule
Made of 2 or more atoms

4. Cell
The smallest unit of life

5. Tissue
Made of many cells

6. Organ
Made of many tissues working together to do the same job

7. Organ System
Made of several organs working together to do a job

8. Multi- cellular Organism
Made of several cells

9. Population
A group of the same organisms living together in a particular environment

10. Community
Several populations living together in a particular environment

11. Ecosystem
Several communities living together in a particular environment

12. Biosphere
All of the worlds ecosystems