The Evolution of the Eukaryotic Cell Essay Example | Topics and Well Written Essays - 2500 words

The Evolution of the Eukaryotic Cell - Essay Example Proponents propose that flagella derived from the symbiotic relationship of a host cell with a parasitic spirochete. A parasitic spirochete attached to surface of the host cell to gain food through the cell membrane, and the host cell gained motility from its whip-like motions. The beneficial relationship between the organisms evolved in the same manner as that of mitochondria and chloroplasts. Serial Endosymbiotic Theory (SET) The endosymbiotic theory related to the primitive origins of the organelles: mitochondria and chloroplasts. According to the endosymbiotic theory, these originated as prokaryotic organisms, which were engulfed by a larger prokaryote through phagocytosis. This larger prokaryote was probably a rickettsia bacterium, which is an anaerobic proteobacteria that was a precursor to the mitochondria organelle. Similarly, chloroplasts come from an autotrophic prokaryote called endosymbiotic cyanobacteria. The theory has in origins in 1905. Konstantin Mereschkowsky with chloroplasts and Ivan Wallin in the 20s advanced a similar idea for mitochondria. Later on, Henry Ris found that they contain DNA. The modern attribution goes to Lynn Margulis for her work in 1981, Symbiosis in Cell Evolution. She contended that eukaryotic cells started as communities of networking bodies such as endosymbiotic spirochetes that developed cilia and flagella. The problem with this is that cilia and flagella do not c ontain DNA. Another organelle, the peroxisome, is thought to have emerged this way. They, too, do not contain DNA, however. Christian de Duve's peroxisome idea did not last long. (Cooper, 2005) Modern evidence that suggests the endosymbiotic theory is viable: Mitochondria and chloroplasts contain DNA, which is... The endosymbiotic theory related to the primitive origins of the organelles: mitochondria and chloroplasts.   According to the endosymbiotic theory, these originated as prokaryotic organisms, which were engulfed by a larger prokaryote through phagocytosis.   This larger prokaryote was probably a rickettsia bacterium, which is an anaerobic proteobacteria that was a precursor to the mitochondria organelle.   Similarly, chloroplasts come from an autotrophic prokaryote called endosymbiotic cyanobacteria.   The theory has in origins in 1905.   Konstantin Mereschkowsky with chloroplasts and Ivan Wallin in the 20s advanced a similar idea for mitochondria.   Later on, Henry Ris found that they contain DNA.   The modern attribution goes to Lynn Margulis for her work in 1981, Symbiosis in Cell Evolution.   She contended that eukaryotic cells started as communities of networking bodies such as endosymbiotic spirochetes that developed cilia and flagella.   Another organelle, th e peroxisome, is thought to have emerged this way.   They, too, do not contain DNA, however.   Modern evidence that suggests the endosymbiotic theory is viable:†¢ Mitochondria and chloroplasts contain DNA, which is different from that of the cell nucleus, and that is similar to that of bacteria (in being circular and in its size).  Ã¢â‚¬ ¢ They are surrounded by two or more membranes, and the innermost of these shows differences in composition compared to the other membranes in the cell.