Jeffrey R. Groff, Institute of Environmental and Physical Sciences, Shepherd University, Shepherdstown, WV Bioscience and premedical profession students are a major demographic served by introductory physics courses at many colleges and universities. Exposing these students to biological applications of physical principles will help them to appreciate physics as a useful tool for their future professions. Here I describe an experiment suitable for introductory physics where principles of wave optics are applied to probe the size of onion epidermal cells. The epidermis tissue is composed of cells of relatively uniform size and shape (Fig. 1) so the tissue acts like a one-dimensional transmission diffraction grating. The diffraction patterns generated when a laser beam passes through the tissue (Fig. 2) are analyzed and an estimate of the average width of individual onion epidermal cells is calculated. The results are compared to direct measurements taken using a light microscope. The use of microscopes and plant-cell tissue slides creates opportunities for cross-discipline collaboration between physics and biology instructors.
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机译：杰弗里·R·格罗夫（Jeffrey R. Groff），谢泼德大学环境与物理科学研究所，谢泼兹敦，西弗吉尼亚州生物科学和医学专业的学生是许多学院和大学开设的入门物理课程所服务的主要人群。让这些学生接触物理原理的生物学应用将有助于他们认识物理学，将其作为未来职业的有用工具。在这里，我描述了一个适用于入门物理学的实验，在该实验中，将波光学原理应用于探测洋葱表皮细胞的大小。表皮组织由大小和形状相对均匀的细胞组成（图1），因此组织的作用就像一维透射衍射光栅。分析了激光束穿过组织时产生的衍射图样（图2），并计算了单个洋葱表皮细胞平均宽度的估计值。将结果与使用光学显微镜进行的直接测量进行比较。显微镜和植物细胞组织玻片的使用为物理学和生物学指导者之间的跨学科合作创造了机会。
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