Learning to teach science in effective ways extends beyond mastering the methods of teaching. With culture representing such a central place within our understandings of science and diverse classrooms, learning to negotiate a variety of cultures is central to teachers' learning. There are many cultures teachers need to negotiate: the students' communities, the school community, and the community of science. Using their knowledge of these different cultures, teachers shape the culture of their classrooms. Teaching science in an equitable fashion is far more involved than treating all students in the same way. The degree to which the students' backgrounds depart from those of their teacher suggests that it is actually unfair to treat all students the same. To disregard cultural, ethnic, language, and social class differences clearly places those students who have less in common with their teacher at a disadvantage in the classroom.