This PPT is used as a supportive presentation after the blood cells open notes have been completed. However, it can be used at any time, even as a review after the unit on blood cells has been completed. There are many opportunities for questioning and student participation throughout the PPT. There are two video links embedded into the last slide on how snake venom affects blood (ewwww). Lots of full-color pictures, actual blood smears, electron micrographs (colored) and clip art to enhance student understanding of the material. May also be used when learning about blood spatter during a forensics unit.