1. Characteristics of Life
These SIX criteria must be met in order for something to be considered living:

2. The Six Characteristics
Cells
Made up of Similar Chemicals
Grow and Develop
Sense and Respond to Change
Reproduction
Energy

3. 1. All living organisms are made up of at least one cell
Unicellular = one cell
Multicellular = more than one cell
Multicellular organisms can be organized:
Cells  Tissue  Organs  Organ Systems

4. Living Organisms are made up of similar chemicals
Examples:
Water (H2O)
Carbon (C)
Hydrogen (H)

5. 3. All living organisms grow and develop
a. Growth is the process of getting BIGGER 
b. Development is the process of getting more complex (you can do more difficult stuff) 

6. 4. All living organisms sense and respond to changes in their environment
a. The purpose is to make sure that the organism doesn’t change so much that it can’t work properly
b. Homeostasis = ability to adjust to your environment
Examples: “goose bumps,” sweating, blinking/tearing

7. 5. All living organisms are capable of reproduction
a. Organisms can make more of themselves
There are some exceptions!!!
Mule: occasionally 2 species will try to reproduce and the result is a sterile offspring = +

8. 6. All living things require ENERGY!
a. Organisms will find food and EAT it or MAKE their own food
b. Living organisms do a lot of work! We need fuel to do work.