论文部分内容阅读
初中《植物学》“叶的呼吸作用”一节上介绍的呼吸作用实验,演示起来不太方便。我为了加强课堂教学的直观性,在教学实践中,曾利用广口瓶种植小麦做呼吸作用的演示实验,效果良好。在上课前一周,选用1000毫升的广口瓶两个,洗刷干净,瓶底铺1—2厘米厚的湿沙用木棒压平。再把经过冷水浸泡4小时以上、用温汤或福尔马林消过毒的小麦种子均匀地放到广口瓶底部的沙床上,种子之间的距离约5毫米为宜。然后开着瓶口,放到温度15—20℃室内明亮的窗台上。由于沙的通气性较好,种子会很快萌发,要经常用滴管徐徐加入清水,保持沙床湿润。过5—6天就能长成5—6厘米高的绿色麦苗(如图左)。
Junior high school “botany” “leaf respiration” section describes the respiration experiments, the demo is not very convenient. In order to strengthen the visual teaching in class, in my teaching practice, I used the demonstration experiment that the jar was used to do the respiration of the wheat with good effect. In the week prior to class, choose two 1000 ml jars and clean it. The bottom of the bottle is covered with 1-2 cm thick wet sand and flattened with a wooden stick. And then soaked in cold water for more than 4 hours, with warm soup or formalin disinfection of wheat seeds evenly into the bottom of the jar on the sand bed, the distance between the seeds is about 5 mm is appropriate. Then open the bottle, put the temperature 15-20 ℃ indoor bright windowsill. Due to the better aeration of the sand, the seeds will germinate quickly, and the water should be slowly added to the sand dropper to keep the sand bed moist. After 5-6 days can grow into 5-6 cm tall green wheat seedlings (pictured left).