Question

I already have another question pertaining to endosymbiosis. I understand that secondary endosymbiosis involves a eukaryote swallowing another eukaryote. And I also understand that the primary endosymbiosis of proteobacteria eventually led to mitochondria. But in regards to mitochondrias, on their own outisde of a cell are they considered eukaryotes or prokaryotes? In essence, would a eukaryotic cell swallowing a mitochondria be another version of primary endosymbiosis because mitochondrial on their own are bacterias?

Answer 1

Endosymbiotic theory was proposed Lynn Margulis. She proposed the theory by observing prokaryotes and eukaryotes cells and in comparison with fossil samples and named her theory as the endosymbiotic theory.

She proposed that mitochondria in eukaryotes appeared because of endocytosis of aerobic bacteria. Aerobic bacteria means that these are prokaryotes. This theory is also supported because the mitochondrial genome and that of aerobic bacteria are somewhat similar.