An overview of the structure and function of a complex, multicellular organism. This article discusses levels of organization and examples of systems.

Learn about the cell theory and levels of organization in a multicellular organism.

To describe the diversity of unicellular organisms which arose over 2 billion years of evolution.

Observe organisms in various environments, determine what enables the organisms to live in that environment and discuss the varied biological functions of the organisms.

In this multi-media module students derive the relationship between single-celled and multi-celled organisms and the increasing complexity of systems.

[Free Registration/Login may be required to access all resource tools.] Learn how multicelled organisms have specialized cells that do specific jobs and single celled organisms exist without the help of other cells.

How does an organism go from a single cell to something as complex as a frog, fly, or human being? Learn the basic principles of development.

FSERL: Explanation of the hierarchical levels of living things.

Learn how the Cell Theory defines living organisms.

[Free Registration/Login may be required to access all resource tools.] A variety of learning opportunuties about levels of organization in the human body. Includes videos, activities, discussion questions, and quizzes.

This investigation allows students to observe cells from multiple sources. Plant, animal and bacterial cells will be observed as well as cells from multicellular organisms and single-celled organisms. After providing written descriptions...

A brief essay about older and more recent ideas on when the first cells evolved. Good coverage of different scientific theories about the origin of life.

[Free Registration/Login may be required to access all resource tools.] Protists are eukaryotes, which means their cells have a nucleus and other membrane-bound organelles. Most protists are single-celled. Other than these features, they...

Explore the levels of organization in the human body.

A collection of video lectures from an introduction to biology course taught at Massachusetts Institute of Technology. The course covers fundamental topics like biochemistry, genetics, molecular biology, and cell biology with thirty-four...

Explains cell structure and function and describes the parts of a cell.

Organisms are made of cells. Most organisms are multicellular and have cells that are specialised to do a particular job. Microscopes produce magnified images of cells so we can study them in detail. This lesson focuses on animal cells.

Read this passage and study the graphics to complete a five-question quiz on the Immunology of Acute vs. Chronic Inflammation.