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:
... (1471-1541), conqueror of the Inca Empire
Marco Polo, (1254-1323), travelled to China in the 13th century.
John Wesley Powell, (1834-1902), explorer, ...