Alabama Learning Exchange
Alex: What Is Alive?
This lesson is the opening lesson for a unit of study entitled "Why Doesn't A Caterpillar Grow Up To Be An Oak Tree?" during which learners take a look at life cycles of plants and animals. This lesson will encourage students to explore...
University Corporation for Atmospheric Research
Ucar: The Carbon Cycle
A comprehensive introduction to the carbon cycle. The cycle of atoms between living and non-living things is known as a biogeochemical cycle. The most common of these are the carbon and nitrogen cycles.