Levels of Organization of Life Ecosystem Molecule Biome Organ system Biosphere Community Tissue Atom Cell Organism Organ Population Organelle

1. Atom Smallest part of an element that has the properties of that element Example: carbon, hydrogen, oxygen

2 Molecule Two or more atoms together Example: Water (H2O), carbon dioxide (CO2)

3 Organelle Part of cell that carries out a specific job Mitochondria, nucleus

4 Cell Basic unit of life Example: skin cell, nerve cell

5 Tissue Group of cells with a special job Muscle tissue

6 Organ Group of tissues with a specific job Heart, kidney

7 Organ system Group of organs that work together Circulatory system, respiratory system, nervous system

8 Organism A living thing Human, elephant

9 Population Group of organisms living in an area Herd of elephants

10 Community All the living things (populations) that live in an area Elephants, lions, shrubs, zebras

11 Ecosystem All the living things and the nonliving things in an area Example: all the zebras, elephants, lions and the water, temperature/climate, etc.

12 Biome Region on earth with characteristic life and climate Examples:

13 Biosphere The collective area of Earth that supports life. Example: Air, land, water

Levels of Organization of Life Atom Molecule Organelle Cell Tissue Organ Organ system Organism Population Community Ecosystem Biome Biosphere