In biology, particularly cell biology, the term organelle is used to describe any one of a number of types of subcellular structures, historically identified through the use of some form of microscopy.
A few large organelles probably originated from endosymbiont bacteria:
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Alexander von Humboldt, (1769-1859), explored Central and South America, visited Siberia
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Helge Ingstad, (1899-2001), ...