Biology / Unit 9 Bio 1985 short lesson, about 20 seconds
Endosymbiosis Among Protists, Revisited
Captions available
The idea
Mitochondria, per Bio 0274 and Bio 1821, trace to one primary endosymbiotic event; among protists, that same engulf-and-retain pattern also produced chloroplasts.
In practice
A cyanobacterium engulfed by an early eukaryote became the ancestor of chloroplasts in the lineage now called Archaeplastida.
Where people slip
This entry extends endosymbiosis to chloroplast origin— it does not reopen the separately unsettled question of the nucleus's origin.
Your place on the trail
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