Presentation on theme: "Do Now:. Mitochondria & Chloroplasts: Descendents of Ancient Prokaryotes Chloroplasts and mitochondria are responsible for photosynthesis and cellular."— Presentation transcript:
Mitochondria & Chloroplasts: Descendents of Ancient Prokaryotes Chloroplasts and mitochondria are responsible for photosynthesis and cellular respiration in eukaryotes. Chloroplasts Mitochondrion
Endosymbiosis Endosymbiosis: The theory that chloroplasts and mitochondria are descendents of ancient prokaryotes taken in by bigger cells during the process of evolution, leading to eukaryotic cells. Evidence: DNA: chloroplasts and mitochondria both contain their own genes, independent from nuclear DNA. Reproduction: mitochondria and chloroplasts reproduce independently of the rest of the cell Morphology: chloroplasts & mitochondria have double membranes – as would be expected if they were once engulfed. Homology: mitochondria & chloroplasts share many similarities with known prokaryotes that exist today.
Eukaryotes without Mitochondria They’re only a couple of examples, but they exist
Relatives? Mitochondrial DNA is most similar to a group of aerobic heterotrophic bacteria, the alpha- proteobacteria. Unsurprisingly, chloroplast DNA is most similar to that of cyannobacteria, the blue-green “algae.” Over time, the genomes have changed, and they can no longer live outside of the cells in which they are found.
Watch the Movie Though older, the movie shows some great cell biology, and presents good evidence for the endosymbiotic theory.
Maternal Inheritance: mtDNA MtDNA is a useful tool for studying genetics and evolution, since it is not recombined during sexual reproduction The Y-chromosome is similarly useful for studying patrilineal inheritance.
The Most Recent Matrilineal Common Ancestor. Misleadingly referred to as mitochondrial Eve, this ancient woman is the most recent female ancestor all humans alive today have in common. That’s right: the woman from whom you, myself, Michael Jackson, the Dali Lama, and EVERYONE else is descended. She lived about 200,000 years ago in Africa, supported by both fossil and DNA evidence.