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Is evidence for the endosymbiont theory explaining the origin of mitochondria and chloroplasts?
According to the endosymbiotic theory of the origin of both chloroplasts and mitochondria, the ancestors of these two organelles were free-living prokaryotic cells.
This theory states that an early eukaryotic cell engulfed a prokaryotic cell by endocytosis, much as one of our phagocytic white blood cells engulfs a bacterium.
On this occasion, however, for some reason (a mutation having changed a protein on the surface of the smaller cell, perhaps?) the prokaryote was not digested, but remained in a structure which evolved into the modern chloroplast, whose outer membrane was the infolded eukaryotic one, and with an inner membrane representing the original prokaryotic plasma membrane. This particular prokaryote was, unlike the larger cell, capable of photosynthesis.
In this relationship, both species benefited. The larger cell gained the ability to synthesize its own organic compounds from inorganic ones, and the smaller cell no longer had to search for protection or inorganic nutrients.
The same theory assigns the origin of mitochondriato a similar, much earlier, event involving the engulfing of an aerobic prokaryote by a larger cell.
"Endosymbiosis" refers to the relationship between two species (symbiosis) in which one is inside (endo-) the other.
Evidence for the theory includes:
the size and shape of the organelles;
their possession of a surrounding double membrane, the outer membrane more eukaryotic and the inner more prokaryotic in chemistry;
the presence of DNA in both organelles, in the form of a circular molecule lacking associated proteins, with genes, transcription, and translation;
the presence in both organelles of ribosomes that are similar in size to prokaryotic ones;
the division by both organelles in a manner like binary fission.
What else can I help you with?
What evidence indicates that mitochondria and chloroplasts were once free-living organisms?
Both have their own DNA, and manufacture their own RNA and proteins. When the DNA was examined, it was resembled the DNA in free-living organsims known as blue-green algae, so it was hypothesized that these organelles were once free-living and then became endosymbionts with another organism.
American biologist who provided evidence for the endosymbiotic theory which explains the origin of chloroplasts and mitochondra?
Lynn Margulis is the American biologist known for her work on the endosymbiotic theory. She proposed that chloroplasts and mitochondria evolved from ancient prokaryotic cells that were engulfed by a host cell. Her research provided evidence supporting the idea that these organelles have their own DNA and replicate independently within eukaryotic cells.
How many times is chloroplast larger than mitochondria?
This is a relatively complicated question as the exact origins of mitochondria and how they came to be included in eukaryotic cells is still under investigation and therefore open to debate.Everyone seems to agree though, that they originally come from bacterium and that they were assimilated into eukaryotic cells either because they were useful or through some form of symbiosis.As mitochondria are common to both plant and animal cells it could therefore be argued that they shared a common ancestor at some point in evolution.The inclusion of the chloroplast came later, and a separate line of mitochondrial and chloroplast carrying cells evolved - eventually becoming plants. The line without the chloroplast becoming animals.
Why do scientists suspect that mitochondria and chloroplasts were originally prokaryotic cells?
Scientists saw that the membranes of mitochondria and chloroplasts resembled the cell membranes of free-living prokaryotes. This led to two hypotheses. One proposed that mitochondria evolved from endosymbiotic prokaryotes that were able to use oxygen to generate energy rich ATP. The other proposed that chloroplasts evolved from endosymbiotic prokaryotes that had he ability to photosynthesize. Mitochondria and chloroplasts share many features with free-living bacteria, such as there ribosomes have similar size and structure and they reproduce by binary fission. These similarities provide strong evidence of a common ancestry between bacteria and the organelles of living eukaryotic cells.
Why are mitochondria and chloroplast considered cells or bacteria?
I'm not sure about chloroplasts, but with mitochondria evolutionary history has led biolgists to believe that the mitochondria now present in eukaryotic cells to have originated a couple billion years ago when a very basic eukaryotic cell injested (ate) a bacterial cell. Then, instead of digesting it for food, the bacterial cell just stayed inside and functioned with the eukaryotic cell. The evidence for this lies in the structure, genetic information (mitochondria have their own DNA and replicate separately) and proteins present. This is why it could be considered a cell (bacterial), because it, at one point in history, was an actual bacterial cell. i think the above answer is a little misleading to the question. so my answer is mitochondria and chloroplast are not considered cells or bacteria. bacteria is a cell and mitochondria and chloroplasts can be found in cells (plant and animal cells, not bacteria cells).
Which is used as evidence for the idea that the domain Eukarya evolved from unicellular organisms?
Mitochondria and chloroplasts have their own DNA.
Is used as evidence for the idea that multicellular organisms evolved from prokaryotes?
Mitochondria and chloroplasts have their own DNA.
What is used as evidence for the idea that the domain Eukarya evolved from unicellular organisms?
mitochondria and chloroplasts have their own DNA
What is the evidence for the endosymbiosis hypothesis?
Evidence for the endosymbiosis hypothesis includes similarities between mitochondria/chloroplasts and bacteria (such as DNA structure and ribosomes), the ability of mitochondria/chloroplasts to replicate independently within cells, and historical precedence in the evolution of eukaryotic organisms. Additionally, the presence of a double membrane in mitochondria and chloroplasts supports the idea that these organelles were once free-living bacteria that were engulfed by an ancestral eukaryotic cell.
The stongest evidence for the endosymbiotic origin of eukaryotic orgelles is the homology between extant prokaryotes and?
...eukaryotic organelles, such as mitochondria and chloroplasts. These organelles have their own DNA, ribosomes, and are similar in size to prokaryotes like bacteria. Additionally, the double membrane structures of mitochondria and chloroplasts resemble what is seen in prokaryotic cells.
What are 3 pieces of scientific evidence that supports the endosymbiotic theory?
The presence of double-membrane structures in mitochondria and chloroplasts similar to bacterial cells supports the theory of endosymbiosis. The existence of circular DNA in mitochondria and chloroplasts, similar to bacterial DNA, provides evidence of their bacterial origin. Phylogenetic studies reveal that the genetic material in mitochondria and chloroplasts is more closely related to certain groups of bacteria than to eukaryotic nuclear DNA, supporting their evolutionary history as once-independent organisms.
What evidence is there for endosymbiotic theory?
One evidence is that both mitochondria and chloroplasts have their own circular piece of DNA that actually codes for a few proteins. This DNA is of the prokaryote type and strongly suggests that the mitochondria and chloroplast were once free living organisms that, one way or another, joined in a symbiotic relationship with a proto eukaryote cell.
What is the evidence for endosymbiotic hypothesis?
The endosymbiotic hypothesis postulates that an early eukaryotic cells lacking mitochondria and chloroplasts phagocytosed early aerobic prokaryotes and photosynthetic prokaryotes and rather than
What part of the cell contains DNA apart from the nucleus?
The mitochondria contain their own DNA in plants and animals; and chloroplasts contain their own DNA in plants and other photosynthetic organisms. Both of these structures divide (almost like cells) inside the cells.*This is also evidence for the theory of endosymbiosis, in which early cells ate early prokarotic cells (bacteria) and gained new organelles.
Which two organelles are used as evidence supporting enosymbiotic theory?
The mitochondria and chloroplasts are used as evidence supporting the endosymbiotic theory. Both organelles have their own circular DNA, replicate independently of the cell, and have a double membrane structure similar to certain prokaryotes.
What is used as evidence for the idea of a domain Eukarya evolved from unicellular organisms?
Mitochondria and chloroplasts have their own dna
Which is used as evidence for the idea that multicellular organisms evolved from prokaryotes?
Mitochondria and chloroplasts have their own DNA
