高中生物课本中“世代交替”部分教材,主要是通过讲述高等植物的世代交替现象,使学生掌握世代交替的概念。这一概念是本课的教学重点,而教学的关键则是通过蕨的生活史的教学,讲清概念,并进行分析说明。怎样做到在教学中突出重点、抓住关键呢?我的体会如下: 用直观方法讲好蕨的生活史教材中在讲述高等植物的世代交替现象之前,先给出了世代交替的概念。但是,一个概念的形成,需要以一定的感性知识为基础的。而讲好蕨的生活史正是形成世代交替这个概念所 High school biology textbook “Alternating generations” part of the textbook, mainly by telling alternate generations of higher plants, so that students master the concept of alternating generations. This concept is the focus of this lesson teaching, and teaching the key is through the teaching of fern life history, make clear the concept, and analysis. How can we achieve the key points in teaching and seize the key? My experience is as follows: Speaking the life history of ferns in an intuitive way The teaching materials of the higher plants tell the alternation of generations before presenting the alternation of generations of higher plants. However, the formation of a concept needs to be based on a certain amount of perceptual knowledge. Speaking about the life history of ferns is the formation of the concept of alternating generations