I applied for a few UCs (UC Berkeley, Davis, Irvine, and Los Angeles) and decided I wanted to major in Bioengineering in all of them before actually researching it. I'm having second guesses about the major after hearing it is not such a good choice if I wanted to enroll in medical school after graduating. I just wanted to know if the majors I put in the application are "set in stone" or in other words, do I have to go along with the majors? Or once I get admitted, do I have to declare the major I am interested in? If I have to go along with it, what are the steps I have to take to change it for each of the UCs?