Online learning is a well-established and growing, yet controversial and widely criticized, component of higher education. In this study, in-person and online versions of an undergraduate introductory biology class were compared to determine whether the online version of the course promoted student performance as well as the in-person course. Student survey responses were also analyzed to identify which teaching modality students perceived to be most effective at promoting learning, and to determine which components of the course were perceived by students to be most effective. No statistically significant difference was observed in exam scores or course grades between the two course modalities. Interestingly, some course components, such as completing virtual labs, were perceived to be more effective in the online version of the course, while others, such as participating in class discussions, were ranked as more effective for the in-person course offering; other components were ranked as similarly effective in both versions of the course. Therefore, this study provides evidence that online education can be effective if appropriately designed and implemented, and it provides a framework for strengthening the effectiveness of online education in the future.