这一实验的材料准备,我感到课本要求的方法,时间长,效率低,不能很好地满足教学需要。根据分析,我认为:凡是具有活力的植物根细胞,就能发生离子交换吸附现象。为了改进这一实验取材,我先后试用了青葱、青蒜和小麦、水稻幼苗等的根(因为单子叶植物根分布浅、数量多、呈须状,从土壤中挖出损失少),都可代替专门培养的洋葱根。因此,可以因时制宜、就地取材,选用 The preparation of this experiment material, I feel the textbook method, a long time, low efficiency, can not meet the teaching needs well. According to the analysis, I think: all the active plant root cells, ion exchange adsorption can occur. In order to improve this experiment, I have tried the roots of shallots, garlic and wheat, rice seedlings, etc. (because of the shallow root distribution of the monocotyledonous plants, the number of them, the whiskers, the less loss from the soil) Specially cultivated onion root. Therefore, we can according to the time, materials, selection