I forgot to mention the other difference. The family can choose to donate a body here – with or without the deceased’s consent. In fact, legally, the deceased’s wishes can always we overridden by the family. The Organ Donor Card that you carry is just a vehicle to let your family know your wishes. They have the last word on what actually happens.
Wha- wha- whaaat?
I find this highly unlikely. Actual body parts are nasty to work with, not least because they stink–either from decay or the nasty chemicals used to preserve them. Not to mention that just getting parts of the right type, from the right race and in the right condition for a particular shot would be problematic, at best. Consistency, too, would be difficult to maintain. Scenes often have to be shot over and over, from many different angles, sometimes over a period of days or even weeks. Real body parts would dry out or otherwise age. It’s much easier to make them out of latex and foam rubber.
It depends on the body part, I would imagine. It used to be possible to buy human skeletons from India, and I imagine low-budget horror movies might opt for the easier route of doing that over synthesizing them.