1, Explain the endosymbiotic theory of the origin of eukaryotic cells in your own words.

2, Compare at least two characteristics of mitochondria to prokaryotic cells and explain how this relates to the endosymbiotic theory.

3. Describe an example of endosymbiosis that has been observed and documented.

(1) The endosymbiotic theory is the theory that concerns the origin of eukaryotic cells. It says that a prototypic nucleated eukaryotic cell obtained both the mitochondria and the chloroplast from engulfing prokaryotes capable of oxidative phosphorylation and photosynthesis respectively. This prototypic eukaryotic cell then evolved to become higher order beings.

(2) Both the mitochondria and the prokaryotic cells have its own genetic material, in fact, the mitochondria has its own DNA (mtDNA) different from the nucleus. This mtDNA undergoes transcription just like prokaryotic DNA to make mRNA and eventually functional proteins.

(3) One primary example of endosymbiosis is the presence of plastids in plants and the presence of mitochondria in animal cells. These represent the prokaryotic organisms that were engulfed by the prototypic eukaryotic cell in the past.