Also, a very rare condition where one person has two completely separate sets of DNA, usually caused when 2 separate zygotes fuse together. One of the embryos has died, but its DNA still exists in the other embryo. Hence, having two different sets of DNA.
One chimera is a pig with the human flesh gene. Pig organs are very similar to human organs, so pigs could be used as organ donors, BUT, the human body rejects the swine's flesh -- UNTIL NOW!
These human-flesh-pigs were too expensive, until the FDA approved them for food.
You swine-eating cannibals!