This lesson includes everything you need to do a lesson on the biology topic: Orgins of cells. It explores the theory of endosymbiosis and comes with everything you need to present an engaging lesson. I have included all worksheets (graphic organizers, handouts and reading passages) as well as relevant answer keys and pictures of the finished product to make your life easier! In this lesson students read a short 2 page article on the topic of cell evolution, they use the information in that article (great for a close reading activity as well), to fill in the associated graphic organizers, foldables and data tables. The lesson overall should take 1 to 1.5 class periods. It is perfect for middle school, high school and home school children.