College Board
2006 AP® Environmental Science Free-Response Questions
There is a strong correlation between the carbon dioxide concentration in the air temperature. Scholars offer explanations for the correlation in one of four AP® free-response assessment questions. Their analyses in the other questions...
Biology Junction
Plant Structure and Function: Roots, Stems, and Leaves
Scientists found fossils of plants more than 420 million years old—but plants existed for up to 100 million years prior to these fossils. Learn about the importance of plants to the entire planet. Viewing a presentation helps scholars...