While there have been concerted efforts to reform undergraduate biology toward teaching students to organize their conceptual knowledge like experts, there are few tools that attempt to measure this. We previously developed the Biology Card Sorting Task (BCST), designed to probe how individuals organize their conceptual biological knowledge. Previous results showed the BCST could differentiate between different populations, namely non-biology majors (NBM) and biology faculty (BF). In this study, we administered the BCST to three additional populations, using a cross-sectional design: entering biology majors (EBM), advanced biology majors (ABM), and biology graduate students (BGS). Intriguingly, ABM did not initially sort like experts any more frequently than EBM. However, once the deep-feature framework was revealed, ABM were able to sort like experts more readily than did EBM. These results are consistent with the conclusion that biology education enables advanced biology students to use an expert-like conceptual framework. However, these results are also consistent with a process of "selection," wherein students who persist in the major may have already had an expert-like conceptual framework to begin with. These results demonstrate the utility of the BCST in measuring differences between groups of students over the course of their undergraduate education.