Curated OER
What Are Cells?
Energize the cells of young biologists with an edible life science activity. Engaging students in exploring the inner workings of plant and animal cells, this activity involves using colored jello and various sweet and...
National WWII Museum
A New War Weapon to Save Lives
Young historians view and analyze photos and documents from WWII that are related to blood transfusions and blood plasma. A demonstration of correct and incorrect blood donors visually shows the importance of knowing blood...
Encyclopedia of Earth
Encyclopedia of Earth: Evolutionary Biology: Organism
Article explaining what organisms are, their cellular foundation, and how they get their energy and nutrition. (Published: May 26, 2010)
Other
Principia Cybernetica Web: Multicellular Organisms
Learn about the transition from unicellular to multicellular organisms. Includes related sources.
BiologyWise
Biology Wise: Multicellular vs. Unicellular Organisms
Describes the characteristics of unicellular and multicellular organisms and gives examples for each.
Biology 4 kids
Biology4 Kids: Animal Systems
An overview of the structure and function of a complex, multicellular organism. This article discusses levels of organization and examples of systems.
City University of New York
Exploring Life: The First Cells
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.
Wikimedia
Wikipedia: Gastrointestinal Tract
Wikipedia provides excellent resources and information on the gastrointestinal or digestive tract, including images and hyperlinked terms.