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2013年北师大版生物教材七年级上册第86页“观察根毛”的分组实验,让学生观察在培养皿中的小麦根毛,主要是观察根毛的形态和密度,认识根与土壤接触的表面积,理解根尖生有根毛的区域是根的主要吸水部位。一、原实验存在的问题在教科书上,该实验是在培养皿中培养根毛,用肉眼和放大镜观察,每年进行的时间是在11月份左右,气温较低,常温下小麦种子萌发的时间很慢,不易观察到根毛。后来,笔者改在恒温箱内(25℃左右)
2013 Beijing Normal University biology textbook grade seven on page 86 “observation of root hair ” group experiments, allowing students to observe the root hair in the Petri dish, mainly to observe the morphology and density of root hair, roots and soil contact Surface area, understanding root root hair root area is the root of the main water-absorbing parts. First, the problems of the original experiment In the textbook, the experiment is to cultivate root hair in petri dishes, with the naked eye and magnifying glass, the annual time is around November, the temperature is low, the germination time of the seeds is very slow at room temperature , Not easy to observe the root hair. Later, I changed the incubator (about 25 ℃)