Yale University
Yale New Haven Teachers Institute: The Circulatory System
A detailed overview of the circulatory system, including plasma and proteins. Designed as lesson plans, this site can be helpful for students as well.
OpenSciEd
Open Sci Ed: 7.4 Matter Cycling & Photosynthesis
Where does food come from and where does it go next? This unit helps students figure out that they can trace all food back to plants, including processed and synthetic food. They obtain and communicate information to explain how matter...