The Levels of Organization

1. Cell: the cell is the basic unit of structure and function of a living thing.

Example: Single Celled Organism     Multi-celled organism     Volvox  

2. Tissue: Tissues are made of a group of similar cells that work together to do a specific job in the body.

Example: Muscles     Nervous      Skeletal   

3. Organs: Organs are made up of two or more tissues that work together to do a specific job.

Examples: Heart     lungs     kidneys

4. Organ Systems: An organ system is a group of organs working together to perform particular jobs.

Examples:  reproductive    digestive    nervous     respiratory

5. Organisms: Sum of all cells, tissues, organs and organ systems makes an organism. An organisms is made when a group of organ systems work together.

Examples: flowers people animals


       All the levels of organization all have a certain job to do or a certain purpose for the organization. The cells are what the organs are made of, without them there would be no organs and without organs there would be no organ systems. If any of these systems were missing the entire organism would not work.