Where the heck did all those structures inside complex cells come from?
Scientists agree that eons ago, a bacterium took up residence inside another cell and became its powerhouse, the mitochondrion. But there are competing theories about the birth of other organelles such as the nucleus and endoplasmic reticulum.
https://knowablemagazine.org/article/living-world/2023/how-endomembrane-system-of-eukaryotic-cells-evolved #microbiology #cells #organelles #bacteria