A multiple origin for plastids and mitochondria.
The impressive homologies between mitochondria and plastids, on the one hand, and procaryotic organisms, on the other, make it almost certain that these important cellular organelles had their origin as independent organisms. The vast number of symbiotic relationships of all degrees of evolutionary antiquity which have been found in contemporary organisms point to the ease with which such relationships can be established.
D005075:Biological Evolution; D002338:Carotenoids; D000460:Chlorophyta / Q000166:cytology; D002736:Chloroplasts; D000458:Cyanobacteria / Q000166:cytology; D004247:DNA / Q000378:metabolism; D004926:Escherichia coli / Q000166:cytology; D005055:Euglena / Q000166:cytology; D056890:Eukaryota / Q000166:cytology*; D008928:Mitochondria; D009491:Neurospora / Q000166:cytology; D010788:Photosynthesis; D013559:Symbiosis
D002338:Carotenoids; D004247:DNA