Bioroids are essentially cloned bodies that have a positronic brain which houses their consciousness. This can be either an Artificial Intelligence, or for those with the resources or the technology, such as the Genocracy, a human mind digitized and transferred into the bioroid.
This is the main means by which the Genocracy prolong their lives until they can find a more permanent solution. They have also been used in replacing individuals who have gone missing, although for what purpose, no one has the answer.
While the technology is real, it is purposefully hidden from the general public. Such things are the stuff of urban legends and is not something the average citizen can discover without someone taking notice.