Biological organization is structured hierarchically, with each level exhibiting unique properties. The hierarchy ranges from atoms, the smallest units of elements, to the biosphere, encompassing all environments on Earth. Key levels include molecules, organelles, cells, tissues, organs, organ systems, populations, communities, and ecosystems.

1. Biological Hierarchy

2. Organization
• Biological organization is based on a
hierarchy of structural levels
• Each level of biological organization has
distinct properties

3. Atom
the smallest
part of an
element
(92 natural)

4. Molecule
A chemical structure made of
bonded atoms

5. Organelle
A structural
component of a cell

6. Cell
Life’s fundamental
unit of structure
and function

7. Tissue
A group of similar cells
with similar function

8. Organ
Specialized body parts
made of tissues

9. Organ
System
Multiple organs working
together to carry out life
functions

10. Organism
An individual
living thing

11. Population
All individuals of
a species in a
particular area

12. Community
All organisms in
an ecosystem

13. Ecosystem
All living and nonliving things in a
particular area

14. Biosphere
All environments
on Earth