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Chloroplasts and mitochondria originated as engulfed bacteria
Endosymbiotic events turned ancient single-celled microbes into vital plant and animal organelles
Endosymbiotic theory explains how complex eukaryotic cells evolved key cellular organelles. Over a billion years ago, ancestral host cells engulfed photosynthetic cyanobacteria and aerobic bacteria, establishing mutually beneficial symbiotic relationships. Over evolutionary timescales, these engulfed microbes transferred most of their genetic material to the host nucleus, becoming chloroplasts and mitochondria.
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Tags: biology, evolution, cells
Chloroplasts and mitochondria originated as engulfed bacteria: the short answers
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- Endosymbiotic events turned ancient single-celled microbes into vital plant and animal organelles. The figure is taken from Smithsonian, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.
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