In this case study, an exemplary seventh grade science teacher's beliefs, planning decisions, implementation, and student reactions to her student-centered methods were examined over a 4-week unit on genetics. This situation was unique because the teacher was new to the profession and her students had no prior experience with student-centered methods. The teacher designed a learning environment where students were expected to take responsibility for research, but initially students felt unsure about the tasks they were assigned and sought out more structure. As the teacher began to scaffold the material, a balance was achieved that resulted in student engagement during the unit. Findings from the case study can provide teacher educators with factors promoting skillful implementation of student-centered classrooms.