What is the origin of mitochondria and chloroplasts?
What is the origin of mitochondria and chloroplasts?
Mitochondria and chloroplasts likely evolved from engulfed prokaryotes that once lived as independent organisms. At some point, a eukaryotic cell engulfed an aerobic prokaryote, which then formed an endosymbiotic relationship with the host eukaryote, gradually developing into a mitochondrion.
What is the mitochondria origin?
Mitochondria evolved from an endosymbiotic alphaproteobacterium (purple) within an archaeal-derived host cell that was most closely related to Asgard archaea (green). The earliest ancestor of mitochondria (that is not also an ancestor of an extant alphaproteobacterium) is the pre-mitochondrial alphaproteobacterium.
What membrane of the chloroplast and the inner membrane of the mitochondrion?
thylakoid membrane
In terms of its role in generation of metabolic energy, the thylakoid membrane of chloroplasts is thus equivalent to the inner membrane of mitochondria.
What is the endosymbiotic origin of organelles?
Endosymbiotic theory posits that plastids and mitochondria were once free-living prokaryotes and became organelles of eukaryotic cells. The theory started with plastids [1] and was further developed for mitochondria [2].
What was the origin of all chloroplasts?
chloroplasts likely originated as free-living cyanobacteria.
Which of the following are evidence that chloroplasts and mitochondria originated by endosymbiosis?
Numerous lines of evidence exist, including that mitochondria and chloroplasts have their own circular DNA (prokaryotes also have circular DNA), mitochondria and chloroplasts have a double membrane (the inner membrane would have initially been the ingested prokaryote’s single membrane, and the outer membrane initially …
Where did chloroplasts come from?
What Is the Origin of Chloroplasts? Like mitochondria, chloroplasts likely originated from an ancient symbiosis, in this case when a nucleated cell engulfed a photosynthetic prokaryote. Indeed, chloroplasts resemble modern cyanobacteria, which remain similar to the cyanobacteria of 3 million years ago.
What is the inner membrane of chloroplast?
The innermost matrix of chloroplasts, called the stroma, contains metabolic enzymes and multiple copies of the chloroplast genome. Chloroplasts also have a third internal membrane called the thylakoid membrane, which is extensively folded and appears as stacks of flattened disks in electron micrographs.
What two organelles originated through endosymbiosis?
There are two major organelles in eukaryotic organisms that have resulted from endosymbiosis, mitochondria (common to most eukaryotes) and chloroplasts (found in plants and algae only), as well as a few less obvious examples.
How does the endosymbiosis theory explain the origin of mitochondria and chloroplasts?
The endosymbiotic hypothesis for the origin of mitochondria (and chloroplasts) suggests that mitochondria are descended from specialized bacteria (probably purple nonsulfur bacteria) that somehow survived endocytosis by another species of prokaryote or some other cell type, and became incorporated into the cytoplasm.
What is the origin of chloroplasts quizlet?
Chloroplasts were originally free-living bacteria that have been incorporated into the cells of plants, a process called endosymbiosis.
