Science Fair Projects

Yes, science fair projects help to teach science. While doing the projects, it basically forces you to look up information on the subject your doing it on, making you learn about that subject. Doing the experiment also teaches you about the scientific process, learning how to record things, and learning how to interpret your results and make it into a conclusion. Science fair projects definitely teach you a lot about science. 

Stem Cell Research

I think the use of stem cells is a good thing. Like the lady in the video, your body might reject a replacement organ but if all of the cells are killed in the organ, your own stem cells can come in and take it over so its pretty sure that your body will take in the new organ.