Yes, unfortunately they did just about anything you can think of to kill a Jew. Jews were like rats to them, they were non-human to Nazis and if the Nazis wanted to test something, they would use a Jew.
to do many things. a lot with twins, to see if eye color could be changed. and to see if they could make conjoined twins out of not conjoined twins. go to wikipedia.org and search "nazi human experimentation" (without the quotes) to see what else they did.
people experiment on guinea pigs because, although they have many features in common with human beings (notably the inability to synthesize Vitamin C), they are not in fact human. The Nazi attitude toward Jews was nauseatingly similar.
Much of Nazi science revolved around the study of genetics and also the limits of the human body. They exploited innocent Jewish (and non-Jewish) prisoners in order to further scientific understanding of how the body and reproduction worked, mostly for sinister reasons.
Part of the Nazi philosophy was de-humanizing of the Jews, who were viewed as "untermensch", or sub-human. That is, the Nazis saw Jews as nothing but animals, so, it was OK to experiment on animals, then, Jews were OK too. In modern terms, the Jews were thought of as cockroaches - disgusting, vile, disease-spreading things that no-one cared about, and people would thank you for getting rid of. So, in the course of their scientific experiments, Nazis simply used Jews rather than animals - after all, they thought, who cares if they are hurt or die? They're not really people, just Jews. And if they could get better (and more applicable) data from their experiment by using a Jew (instead of an animal), well, all the better for that experiment.
The Jews weren't the only ones to be experimented on in this manner - homosexuals, mentally handicapped or mentally ill, Roma (gypsies), and many Slavs (Poles and Russians, in particular) were subjected to the same experiments, for the same reason - the Nazis simply didn't view them as people, and thus, their lives were at the whim of the Nazis.
In terms of the reasons why the Nazis hated the Jews, those are as simply as possible:
controlled experiments
scientific method
they put them in gas chambers, did experiments on them, starved them, beat them, and a lot of other harsh things that you cant ever imagine
The ancient Greeks did not perform any experiments to test the atomic theory proposed by Democritus. To the ancient Greeks the atomic theory was a part of philosophy, not science.
There was no "Nazi medicine". If you are referring to the horrible experiments the Nazis made with human remains, there is no real reason they would attempt organ transplants.
why do scientist perform experiments?
Chemists perform experiments to find out different kinds of matter can change.
Scientists perform experiments to collect data.
Depends on what you call 'useful'. If it is useful to learn how to kill hundreds of people in the shortest amount of time, and to learn how to castrate hundreds of men in the shortest time, then, yeah, they were useful.
They were intreged witht the human body.
Yes Dr. Christiaan Barnard did perform his first experiments on 50 dogs 35 cats and some rats.
things
Experiments.
During the Middle Ages.
To answer specific questions
When the entire country is under Nazi rule, it is very easy. Outside countries had to intervene to stop the experiments and the Nazi party.
To prove or disprove a theory. If you didn't perform experiments you wouldn't have the evidence to move forward in your scientific knowledge. Try an experiment 4 times to get a reliable average result.