This is an incredible 52 slide presentation complete with unique graphics/pictures, examples, small/large group activities, discussions and even a quiz/test at the end. This unit may last from a few classes all the way up to a month. This unit provides lessons that help cover the following National Science Standards (but not limited to):Elementary (K-ESS2, 3.LS-4.D)Middle Grades (MS-LS2-3)High School (HS-ESS 2/3,HS-ESS3-3, HS-LS-1-7. HS-LS4/5)