It all depends. A number of colleges will let things slide in high school if the student shows promise. It's not uncommon for intelligent kids to be rebellious in high school from boredom etc., and so a number of colleges will take a chance on admitting such a student. I knew a guy who was clearly way smarter than the rest of us and when he was motivated to do so could easily pass any class. He got expelled from two high schools and proceeded to ace every class in college.