Yes, this is true, and it is actually one of the organisms driving evolution! Some organisms develop mutations that are actually beneficial (better eye-sight, for example) and they're more likely to pass those to their children that individuals without those mutations!
It would be best to ask a professional on the subject.
temperature regulation, heat absorption, and nutrition transportation
I am not sure but I am guessing carbon and nitrogen :)
The Mitochondria in many cells, are believed to have been bacteria that have been incorporated in the cytophysiology. Mitochondria first off, contain their own DNA, er, RNA. Additionally physiologically the mitochondrion, has an inner membrane and some organelle traits similar to prokaryotic cells. Lastly Mitochondria are the only organelle capable of replicating itself. <span />
