Your friend had a spinal cord injury after a bad car accident. The medical team has decided that he is a good candidate for a clinical trial using stem cell therapy. Your friend has not had a biology course since high school, so you decide to write him a letter sharing your knowledge of stem cells. Include in your letter a description of the biology of stem cells and how these cells are unique from other cells. Contrast the different types of stem cells, including pros and cons of each. Explain how stems cells are can be used to treat diseases and injury, with special focus on spinal cord injuries. Conclude with your own opinion.