Ninety-five percent of all living things break down into four elements sometimes referred to as the CHON: carbon, hydrogen, oxygen, and nitrogen. Topics include: The Nitrogen Cycle, Nitrogen Fixation, Carbon Transfer, and The Continuous Actions of Natural Cycles.

Originally released by Cerebellum Corporation, 2013. Streaming video file encoded with permission for digital streaming by Infobase on July 10, 2018.

Summary: Nitrogen and Carbon Cycles (2:36); --Carbon Returns to the Atmosphere (3:47); -- The Carbon Cycle (3:18); -- The Nitrogen Cycle (5:03); -- Biogeochemical Cycles (2:11); -- Nitrogen and Carbon Cycles in Nature: Introduction (2:25); -- The Nitrogen Cycle (1:09); -- Nitrogen Fixation (3:54); -- The Carbon Cycle (3:18); -- Carbon Returns to the Atmosphere (3:48); -- Access to Summary (2:46); -- Credits: The Nitrogen and Carbon Cycles in Nature (2:15);.