1. The Characteristics of Living Things
Biologists use eight characteristics to classify something as a living thing.
1. Made of One of More Cells
2. Display Organization
3. Grow and Develop
4. Reproduces
5. Responds to Stimuli
6. Requires Energy
7. Maintains Homeostasis
8. Adaptations evolve over time

2. The Characteristics of Living Things
All living things have these eight characteristics.
Anything without one of these eight characteristics is nonliving.
Living things are called organisms.

3. 1. Made of Cells Organisms are made up of one or more cells.
A cell is the basic unit of structure and function in living things.
Cells = the
“Building Blocks"
of life.

4. 2. Display Organization
This means they are arranged in an orderly way.
Cells are organized into groups called tissues – tissues are organized into groups called organs – organs are organized into organ system – organ systems are organized into organisms.

5. 3. Use and Need Energy All organisms need and use energy to live.
Energy is the ability to do work.
Sunlight is the source of energy for most living things.
Plants use the energy in sunlight to make food, and animals get energy by eating plants or other animals that have eaten plants.

6. 4. Grow and Develop All organisms grow and develop.
Living things change, or develop, during their lifetimes.
One way organisms change is by growing- addition of mass.
Living things may also change in appearance.
For example: tadpoles and frogs

7. 5. Reproduce Organisms produce more organisms of their own kind.
Reproduction allows organisms to continue living on the earth.

8. 6. Respond to Stimuli Organisms react to change in their surroundings.
Any reaction to change is called a response.
For example: A bright light may cause you to blink.

9. 7. Require Energy
Living things need sources of energy to fuel their life functions. Living things get this energy from food.
Most plants use light energy to make food.
Animals get energy by consuming other organisms.

10. 8. Maintain Homeostasis
Homeostasis is the ability of an organism to regulate internal conditions.
If anything happens within or to an organism that affects its normal state, processes to restore the normal state begin.
Ex: athletes that travel to higher altitudes arrive days earlier so their bodies have time to adjust to the thinner air (the body will produce more red blood cells).

11. 9. Adaptations evolve over Time
An adaptation is any inherited characteristic that results from changes to a species over time.
Adaptations develop to help an organism survive and pass on their genes to their offspring.