1. Endosymbiotic Theory By: Shawn Fassl

2. Theorist Biologist Lynn Margulis backed the theory of endosymbiosis in the 1970s Origin of life came from lineages through symbiosis Published The Origin of Eukaryotic Cells in 1970 Endosymbiotic Bacteria- Bacteria within other cells that perform specific functions for their host

3. Origin of Eukaryotic Cells

4. Endosymbiosis Symbosis- different species benefit from working and living together Endosymbiosis- Living together in close association (One living inside the other) Endosymbiotic Theory- Explains the origin of mitochondria and chloroplasts through symbiotic relationships Critical stage in the evolution of eukaryotic cells One prokaryotic cell engulfed another cell resulting in a symbiotic relationship

5. Endosymbiosis Process

6. Evidence The engulfed cell provided special metabolic abilities beneficial to their hosts Two organelles are believed to have descended from these prokaryotes. (Mitochondria and Chloroplasts). Mitochondria from aerobic heterotrophic prokaryotes Chloroplasts from photosynthetic prokaryotes Mitochondria and Chloroplasts can only arise from preexisting organelles.

7. Association Entered the cell as a parasite or prey of prokaryote Turned from Parasitism to Mutualism

8. Mitochondria and Chloroplasts Mitochondria and Chloroplast support Margulis’s Theory These include: - Both have an outer and inner membrane - Each have their own DNA (similar to bacteria) - Similar in size to a eubacteria - Mitochondria have their own genome - Ribosomes similar to bacteria in size and structure

9. Mitochondria & Chloroplasts

10. References Mason, Kenneth A., Jonathan B. Losos, Susan R. Singer, Peter H. Raven, and George B. Johnson. "Chapter 4." Biology: Evolution, Diversity and Ecology: Selected Materials from Biology, 10th Edition. N.p.: n.p., n.d. N. pag. Print. "The Evolution of the Cell." Learn.Genetics. N.p., n.d. Web. 29 Oct. 2014. "Endosymbiosis: Lynn Margulis." Understanding Evolution. Berkeley, n.d. Web. 30 Oct. 2014