How Stem Cells Work

9/9/2014, 2:36:14 PM , duration(0:0:2)
Society & Culture
Since scientists realized there is a type of cell that can grow into any other type, they have worked to use them to heal human conditions like Parkinson's and immune disorders. But because stem cells often come from embryos they remain controversial.<br><br> Learn more about your ad-choices at <a href=''></a>