Ultraviolet (UV) -irradiated damage and photoreactivation in larvae of the fruitfly, Drosophila melanogaster strain Canton S (wild type), were examined to introduce these phenomena into laboratory exercises in high school biology.
UV irradiation was carried out by a germicidal lamp (UV-C) and a healthy UV lamp (UV-B). After UV-irradiation, the larvae were grown in the dark at 25°Cuntil eclosion. The survival of UV-B-and UV-C-irradiated larvae to adulthood was observed among larvae which were irradiated by the intensities of 0-900J/m2 (UV-B) and 0-250J/m2 (UV-C), respectively. The higher dose UV-irradiation does, the less Drosophila survived. Photoreactivation was examined after irradiating UV: The irradiated larvae were exposed to fluorescent light for 24 hours at 25°C. The survival of UV-B and UV-C-irradiated larvae to adulthood was observed among larvae which were irradiated by the intensities of 0-2300J/m2 and 0-650J/m2 respectively. Post-treatment with fluorescent light enhanced the survival rate of larvae that were UV-irradiated (Photoreactivation). This result indicates that the UV-induced lethality was rescued by photoreactivation.
We propose that this experiment is useful for biology education in high schools.
Identification of plants is one of the exercises most suitable for stimulating observation of nature, and it may be practiced at different levels, from elementary schools to universities. There exist a variety of teaching materials for identifying plants, in a form of tables, index cards, computer software, and so on. In developing such teaching materials, easy access to data on the targeted plants and their characters plays an important role. A large database storing 2,172 species of seed plants in terms of their 162 characters was compiled, which is addressed in this paper as a “Database for Plant Identification”. The database was developed in order to assist teachers in assembling data for the plants they selected. Computers are extensively used in both development and use of the database. Database retrieval software provides efficiency and ease of use in gathering the data on the targeted plants and greatly contributes to effective identification exercises. A direct use of the database by students also provides a theme of the project study for high schools.