1. INTRODUCTION TO BIOLOGY
Levels of Organization

2. Atom
The basic unit of all matter

3. Molecule
Group of two or more atoms held together by chemical bonds

4. Cell
The basic unit of living things

5. Tissue
Group of cells of the same type

6. Organ
Structure composed of two or more tissues that work together to perform a specific function

7. Organ System
Group of organs that work together to perform certain functions

8. Organism
Individual living thing made up of several organ systems

9. Population
Group of organisms of the same species that live together in a particular location

10. Community
Group of distinct populations that live in a particular location

11. Ecosystem
All the communities and the non-living parts in a particular location

12. Biome
A group of ecosystems that have the same climate and similar communities

13. Biosphere
Part of the earth where all life exists and includes the land, water and air or atmosphere