Developing new teaching materials to show the influences of Ultraviolet radiation on organisms for environmental education

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Stratospheric ozone depletion is a concern because the ozone layer in the stratosphere keeps 95-99% of the suns ultraviolet(UV) radiation from striking the earth. A number of consequences can result from increased levels of 1W striking the earth, including : genetic damage, eye damages and damage to marine life.To make students understand these rerelationships scientifically, we schemed out following methods in experiments, In the all experiments , we used a 1OW UV lamp(germicidal lamp) to apply UV light at 30cm.1. The pericarp of banana changed its yellow color to brown when it had received UV radiation for 2-3 minutes followed keeping in a dark room. This color change is available for the estimation of UV radiation. The tranamission factor of several materials for the UV radiation was studied by covering the surface of banana with the test materials.2. The one minute UV irradiation coused death in 99% of yeast cells, but the photorecovery was observed in the dying process. Using yeast cells as a material we can treat the potorecovery quantitatively.3. The thallus of duckweed (Spirodela punctata) was suppressed its growth by more than 20 min irrdiation of UV.The attacked thalluses lost its chlorophyl color gradually, and became white in color within a few days after the irradiation.4. In ampibian embryos (Xenopus laevis), UV irradiation over 50 minuts caused their abnormal cleavage, and then the living rate of them decreased at 36 hr after the irradiation. According to the prolongation of irradiation time, in the living embryos, the rate of embryos which developed abnormal form were increased.5. We made protocol of practical approach with the aspect of biological protection mechanism for (UV) radiation, and evaluate the importance to our environment and environment education.