The LI-6200 gas exchange system (LI-COR Biosciences), an instrument used for measuring leaf level photosynthesis and conductance rates in the field or laboratory, has been replaced by the LI-6400 model for research purposes. However, the LI-6200 can still be an effective tool for teaching photosynthesis using inquiry-based learning techniques. At Ohio Wesleyan University, we have used the LI-6200 for the past five years as part of our laboratory curriculum in introductory botany to teach basic concepts, such as the light dependence of photosynthesis, the effects of whole plant stress on the photosynthetic process, and the simple fact that plants do respire. Our teaching assessment data has indicated that this last concept is particularly difficult for introductory students. 

Results/Conclusions

This presentation will describe in detail the lab exercise we have designed, the potential benefits to students, and pitfalls to avoid for the instructor. While purchasing the LI-6400 is obviously the best choice for teaching programs that have the means to buy new instruments, institutions that still have the LI-6200 can use this instrument effectively in the classroom. Even with this older model, students gain valuable hands-on experience with scientific equipment, can make and test predictions about the photosynthetic process, and can see more clearly the link between photosynthesis and atmospheric CO₂, a key concept for citizens in today’s rapidly changing global environment.