The psychic is, quite literally, the new kid on the block as far a psychics go; his name is Tyler Henry, and apparently the basic cable channel E! is really pushing a TV series featuring him, Hollywood Medium With Tyler Henry. His website describes him thusly:
Mitochondrial DNA is only a small portion of the DNA in a eukaryotic cell; most of the DNA can be found in the cell nucleus and, in plants, in the chloroplast. In humans, the 16,600 base pairs of mitochondrial DNA encode for only 37 genes.
The main difference between nuclear DNA and mitochondrial DNA is, nuclear DNA is the standard 46 chromosome containing DNA in which you inherit 23 chromosome from one parent and the rest 23 from another one. On the other hand, mitochondrial DNA contains just one chromosome, like a circular genome.