This two-year investigation examined the relationship between class attendance, participation, and final class grade (Final GPA) in an Introductory Biology course for prehealth majors. We also examined the effect of students' attendance at voluntary review sessions on final GPA. Student participation and attendance, as well as DFW rates (percent of students earning D or F or withdrawing), for the four semesters were analyzed as indicators of student dedication. An analysis of DFW rates and attendance indicated that Fall semester students had greater participation in review sessions than Spring semester students. In addition, a significant correlation was found between the number of review sessions attended and the student's final grade. Student data were divided into four groups based on their success in the first exam and their attendance at review sessions to assess the effect of review sessions. The results showed that review sessions were beneficial for students who did well on their first exam as well as for students who did not do well on their first exam. We interpret these data as a positive effect of self-motivated student engagement outside the classroom on academic performance in freshman Biology.