The association between mitochondria and eukaryotic cells is thus the result of an ancient symbiosis between two very different types of unicellular organism.
(The association between mitochondria and eukaryotic cells; is thus; the result of an ancient symbiosis between two very different types of unicellular organism)
The association between mitochondria and eukaryotic cells
is thus
the result of an ancient symbiosis between two very different types of unicellular organism