The Biology Department recently implemented changes to the laboratory components of its General Biology courses. The changes institute an experimental approach to laboratory study centering on open-ended investigative experiments and introducing selected instrumentation, statistical analysis and formal report writing. Each course contains three weeks of lab study of respiration; in the first semester the focus is on anaerobic fermentation by yeasts and in the second semester on whole organism respiration of cockroaches. We presently use a modified Scholander apparatus that measures gas pressure changes in a closed system. Funds are requested for the purchase of Li-Cor Portable Photosynthesis Systems, capable of rapid accurate measurements of CO2 fluxes produced by living material placed within a measurement chamber. These instruments will replace the relatively unreliable equipment we are now using and will extend the instructional capability of the laboratory in the following ways. The fast response time and high sensitivity of the system will allow each student to run more replicates during a three hour laboratory, improving the sensitivity of statistical analyses performed later. Students will be able to choose from a wider range of treatment effects when designing their own investigations, because finer distinctions among rates will be possible. In addition, the equipment will significantly improve the quality of laboratory investigations into photosynthesis in the General Botany course.
