Hypothesize whether prokaryotic cells might have been symbiotic before the evolution of eukaryotic

Some scientists hypothesize that the eukaryotic cells are really the result of symbiotic processes!

Specifically, the internal organs of the cells could be a remnant of a symbiotic relationship in which one cell lived inside of another cell. These two cells then both split upon reproduction and eventually the cell inside was reduced to an organelle.

But according to this theory, it is very likely that the prokaryotic cells engaged in a number of symbiotic relationship, and that this actually lead to the emergence of eukaryotic cells!