This investigation explores how underrepresented urban students made sense of their first experience with high school science. The study sought to identify how students' assimilation into the science classroom reflected their interpretation of science itself in relation to their academic identities. The primary objectives were to examine students' responses to the epistemic, behavioral, and discursive norms of the science classroom. At the completion of the academic year, 29 students were interviewed regarding their experiences in a ninth and tenth-grade life science course. The results indicate that students experienced relative ease in appropriating the epistemic and cultural behaviors of science, whereas they expressed a great deal of difficulty in appropriating the discursive practices of science. The implications of these findings reflect the broader need to place greater emphasis on the relationship between students' identity and their scientific literacy development. © 2005 Wiley Periodicals, Inc. J Res Sci Teach 43: 96–126, 2006