The mitochondrion has its own DNA transcribes its own DNA has DNA that functions independently of nuclear DNA has DNA that is somewhat different from nuclear DNA all of these?

Answer 1

Yes, mitochondria have dissimilar DNA to nuclear DNA. That is because mitochondria arose endosymbiotically as an invasion of an early eukaryotic (nucleated) cell by a purple bacterium in a relationship which was subsequently symbiotic. Many mitochondrial substances are encoded for by the mitochondrial DNA. Some others important to mitochondrial function are also encoded by nuclear DNA. But yes, the mitochondrion would have to carry out its own transciption to make the products it itself coded for. As the mitochondrion was once an autonomous bacterium (way back in Cambrian or Precambrian times), its genome would be different to the actual genome of the organism's cell (in the nucleus) in which it resides. And thus for the large part it would function utterly independently. But there may be inteferences that evolved over the billions of years since the system's origin. As I said the nucleus itself encodes for at least some products essential to mitochondrial function.