Watch this video and complete the Viewing Guide.
Source: CET, The Cincinnati Zoo and Botannical Garden, ThinkTV http://youatthezoo.org/
Read the article, watch this video, answer the questions.
Source: ©2003 WGBH Educational Foundation. All rights reserved.
PHOTOSYNTHESIS VIDEO: (*Watch this, no quiz or viewing guide)
Source: © 2002 WGBH Educational Foundation. All rights reserved. Adapted from NOVA: "Earth." Produced by WGBH in cooperation with NASA. Third party materials courtesy of BBC and Canadian Broadcast Corporation.