Development of laboratory exercises for studying "Plant growth and morphogenesis" in upper secondary school biology.

通过对现行中学生物学教材的分析，我们发现，在植物生长和形态发生方面，学生的实验练习不够。我们的研究项目是组织开发实验室练习，这是既简单又有用的高中生物学研究这些主题。研究内容包括教材的开发、实验条件的考察、实验程序或仪器的简化等，其中“细胞分裂素对离体黄化黄瓜子叶的绿化和肿胀的影响”和“利用Evergren枝条检测成熟果实中乙烯的释放”两个模块对研究植物生长物质的作用似乎是有用的。其他三个模块，“豆科植物小叶的睡眠运动-光敏色素介导现象”、“光对黄化菜豆幼苗中上胚轴钩展开的影响”和“光对种子萌发的影响”，似乎有助于研究光对植物生长和形态发生的影响。单色光的供应对于获得好的结果是必要的。除了普通的荧光灯和彩色滤光片外，我们还使用了用于农业光周期调节的特殊荧光灯，以获得不同波长的光。在高中生物课上对上述模块进行了测试，证实了它们的实用性。

After analyzing the present biology textbooks prepared for the secondary level, we concluded that not enough laboratory exercises are offered for the students to study plant growth and morphogenesis. Our research project was organized to develop laboratory exercises which are both simple and useful for studying these topics in upper secondary school biology. The research included the exploitation of teaching materials, examination of experimental conditions and simplification of experimental procedure or apparatus.Two modules, "Effect of cytokinins on the greening and swelling of the excised etiolated cucumber cotyledon" and "Detection of ethylene evolved from ripening fruits by use of an evergren twig" seem to be useful for studying the action of plant growth substances. The other three modules, "Sleeping movement of leaflets of Leguminosae - a phytochrome mediating phenomenon' "Effect of light on the uncurling of the epicotyl hook in etiolated kidney bean seedlings" and "Effect of light on the seed germination", seem to be useful for studying the effect of light on the plant growth and morphogenesis.For examining the effect of light, the supply of monochrome light is necessary to get a good result. Besides ordinary fluoresent lamps and color filters, we used special kinds of fluoresent lamps which are used for the regulation of photoperiodis in agriculture to obtain different wavelengths of light.Some of the modules listed above were examined in upper secondary school biology classes and their usefulness was confirmed.