In high school biology, we all learned that mitochondria are the powerhouse of cell. For anyone who slept through it, mitochondria are the bacteria-like organelles found in the gooey cytoplasm of eukaryotic cells. Eukaryotes are a special subset of organisms that have a nucleus to house their DNA. Here you can see the noteworthy differences between eukaryotes and prokaryotes, which have no nucleus:
Mitochondria are different from other organelles for two important reasons.
Firstly, they are necessary for cells to produce energy as they are central to the process of cellular respiration.
Secondly, they contain their own DNA and are believed to have once existed as separate prokaryotic organisms that entered the cells of ancient eukaryotic organisms in a symbiotic exchange - ATP (energy) production for protection.
Because of the importance of their functions, scientists hypothesized for many years that they were indisputably necessary for the survival of a eukaryotic cell. A paper published in Current Biology last week, however, has brought all of that into question. The team from the University of British Columbia has reported the discovery of a single-celled eukaryotic organism, called Monocerconoides, native to the gut of the chinchilla, that apparently survives without our favorite organelle.
The researchers have guessed that, since oxygen (a necessity for cellular respiration to occur) is scarce in its native environment, mitochondria became more trouble than they were worth and were ejected by the cell.
Monocerconoides has simply adopted the DNA from a bacterium that performs the necessary functions of a mitochondrion floating freely in the cytoplasm. This discovery points to a whole host of possibilities for single-celled organisms and speaks to the incredible adaptability of life in general.