Development of a Program for Secondary School Science to Encourage Student Understanding of the Responses of Organisms to Light

这个项目的目的是为中学制定一个研究有机体与其环境之间关系的方案。该程序是从以下角度开发的：某种环境因素在生物体中引发了什么样的反应。拉赫特被选为该项目的环境因素。在开发的程序中，光被教导为光合作用生物体的能源，以及许多生物体启动和停止某些反应的信号。该程序包含以下主题：海藻的颜色与它们的栖息地之间的关系。学生们了解到，一些海藻有特殊的捕光色素来进行光合作用，这与它们的垂直分布有关。本主题包括实验室练习，如光合色素的提取和分离，以及海藻对不同波长光的光合作用反应的检查。光周期和植物形态发生与光的关系。学生们学习到花芽诱导、开花和叶片的自然运动都受光(光的数量和质量)的调节。(L)威斯康星州快速植物花芽诱导的检验，(2)牵牛花的开花，(3)草本植物小叶的开合运动是为本课题而发展的实验室练习。昆虫对光刺激的反应。这项实验以果蝇为研究对象，目的是研究昆虫对不同波长光线的趋光反应，让学生比较昆虫和人类的视觉感受。部分实验已在中学科学课上实施。实施是成功的。为进一步研究该程序提供了一些改进的建议。

The purpose of this project was to develop a program for studying the relationships between organisms and their environment for the secondary school level. The program was developed from the following point of view : what kinds of responses are evoked in organisms by a certain environmental factor. Laght was chosen as the environmental factor for this project. In the program developed, light is taught as an energy source for photosynthetic organisms and as a signal to start and to stop certain reactions for many organisms.The program contains the following topics :The relationship between the color of seaweeds and their habitats. Students learn that some seaweeds have special light-harvesting pigments for their photosynthesis, and this is related to their vertical distribution. This topic includes laboratory exercises such as the extraction and separation of photosynthetic pigments and the examination of the photosynthetic responses of seaweeds to different wavelengths of light.Photoperiodism and plant morphogenesis in relation to light. Students learn that flower bud induction, flowering and the nastic movement of leaves are regulated by light (both quantity and quality of light). Examination of (l) flower bud induction in the Wisconsin Fast Plants, (2) the flowering in morning glories, and (3) the opening-closing movements of oxalis leaflets are the laboratory exercises developed for this topic.The responses to light stimuli in insects. The fruit fly was chosen for this laboratory exercise to examine the phototactic responses to different wavelengths of light through which students can compare the visual sense between insects and human beings.Some of the developed exercises have been implemented in secondary school science classes. The implementations were successful. Some hints to improve the program have been obtained for further studies.