Development of Teaching Aid for Leaf Function and Evaluation of Its Impacts on Student Academic Achievement

This study was conducted to develop teaching aid for photosynthesis and transpiration of plant and to evaluate its application effect on elementary school students. In Korea, the 4^th grade students take lessons on the function of leaves among other plant organs during science classes. For the observation of CO₂ and H₂O change by plant indoor, closed systems (26.5×18.0×49.0cm) were made with transparent acryl with LED lights on the top of them. Sensors of temperature, CO₂, and H₂O were attached inside the systems. CO₂ response time of plant under light condition was compared between two kinds of culture media, perlite and artificial substrate, for plant pot. After one hour of treatment, in perlite pot, the CO₂ concentration was sharply decreased by 333 ppm, however, in artificial substrate pot, the CO₂ concentration was rather increased by 7 ppm. Therefore, to observe CO₂ absorption by leaves in 40 minute class, inorganic media is more efficient than organic media with lots of microorganisms. For experiment time zone, the response of vegetables and foliage plants in the systems were tested in the morning or in the afternoon. The both time zones were possible to observe CO₂ decrease by both plants. Transpiration was shown by much H₂O increase in the pot with leaves than in the pot without leaves. Although little change was shown according to temperature and humidity, after 30 minutes of treatment on average, moisture on the system walls was visible. This teaching aid for leaf function was applied to 4^th grade students in Seoul and the students checked the CO₂ and H₂O change by plants in the systems with or without light and with or without leaves. The academic achievement regarding plant leaf function was significantly higher in experimental group compared to the students in control group.