Eukaryotic Theory: The Endosymbiotic Hypothesis

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There are two kinds of cellular life forms on Earth.Endosymbiotic theory, is a theory of the origin of eukaryotic cells from prokaryotic organisms, first thought of in 1905 and 1910 by the Russian botanist Konstantin Mereschkowski, and gone further into and substantiated with microbiological evidence by Lynn Margulis in 1967.The Endosymbiotic Hypothesis wasn’t developed overnight by a single scientist. The combined work of several researchers over a century of experimentation has led to the Hypothesis we know today. It states that the organelles distinguishing eukaryotic cells evolved through symbiosis of individual single-celled prokaryotes known as bacteria and archaea/Living things have evolved into three large clusters of closely related…show more content…
Acquisitions of these signals by the transferred genes enabled their expression in the host cytosol and sometimes resulted in the replacement of a host gene by a bacterial homolog, a process known as endosymbiotic gene replacement. In a next evolutionary stage, transferred genes acquired sequences encoding targeting signals (e.g., via exon shuffling) that allowed their protein products to be imported into the mitochondrion or the primary plastid. Most proteins targeted to mitochondria and primary plastids carry N-terminal transit peptides that are later removed in the organelle matrix. Mitochondria and primary plastids are surrounded by two membranes. Consequently, their import machineries are composed of two translocons: one for the outer membrane and the other for the inner…show more content…
Those theories called for autogenous rather than symbiotic organelle origins and saw plastids and mitochondria as deriving from invaginations of the plasma membrane from restructuring of thylakoids in a cyanobacterial ancestor of eukaryotes.Later on in time a host cell got in contact with a prokaryotic cell capable of photosynthesis. Lynn Margulis was an american biologist whose endosymbiotic theory of eukaryotic cell development upgraded the modern concept of how life arose on Earth. Like other evolutionary biologists, Margulis believes that life first appeared on the earth about four billion years ago. The first organisms were extremely simple--microscopic droplets of water containing a few genes and enzymes surrounded

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