1. Endosymbiotic Theory

2. The Endosymbiotic Theory
Review:
What is a theory?
What is the difference between prokaryotic and eukaryotic cells?
The endosymbiotic theory is the idea that a long time ago, prokaryotic cells engulfed other prokaryotic cells by endocytosis. This resulted in the first eukaryotic cells.
First proposed by Lynn Margulis
Explains the origin of eukaryotic cells
Explains the origin of certain membrane-bound organelles

3. What Exactly Happened? Ancient Prokaryotes
Chloroplast
Plants and plant-like protists
Ancient Prokaryotes
Heterotrophic bacteria
Nuclear envelope evolving
Photosynthetic bacteria
Mitochondrion
Primitive Autotrophic (Photosynthetic) Eukaryote
Animals, fungi, and animal-like protists
Ancient Heterotrophic Prokaryote
Primitive Heterotrophic Eukaryote

4. Membrane-Bound Organelles
Mitochondria = membrane-bound organelle that produces energy for the cell
Chloroplast = membrane-bound organelle that captures sunlight and uses it to make food for the cell

5. Evidence in support of the endosymbiotic theory:
Similarities between mitochondria, chloroplasts, & prokaryotes:
Circular DNA
Ribosomes
Binary fission

6. Check these out:
Animation: Student form with fill-in’s: Worksheet Notes\ENDOSYMBIOSIS student fill-ins.docx