Question

Mitochondria and chloroplasts are thought to have been ______.

a. free-living prokaryotes
c. protocells
b. early forms of eukaryotes
d. spontaneously generated

Answer 1

The correct answer is free-living prokaryotes. It is believed bacteria of some sort got into the prokaryote, and formed these two organelles.

Answer 2

a. free-living prokaryotes They were then endocytosed, which is part of the endosymbiotic theory.