Hank describes the desperate need many organisms have for nutrients (specifically nitrogen and phosphorus) and how they go about getting them via the nitrogen and phosphorus cycles. Table of Contents: Nitrogen Cycle... Read more »
Hank takes us through the bowels of the human digestive system and explains why it’s all about surface area. Crash Course Biology is now available on DVD! http://dft.ba/-8bCC Like Crash Course? http://www.facebook.com/youtubecrashcourse... Read more »
