一、从试验观察入手,引导学生树立生物与环境相互依存的辩证观点生物的生存离不开环境,生物依靠环境供给的物质和能量而生活,受到光、大气、水、温度及其他生物等环境因子和人的限制;同时,生物的生命活动又不断地影响、改变环境,也影响人类的生存。为使学生树立这一辩证观点,我引导学生分别做了蚯蚓与阳光、水分、温度关系和菜豆的向光性、向水性试验。使学生弄清蚯蚓、菜豆个体对环境的依赖关系,对其它常见的小动物及植物进行实验和观察,判断周围常见动植物的生活环境。让 First, from the experimental observation to guide students to establish a biological and environmental interdependence of the dialectical point of biological survival is inseparable from the environment, living creatures rely on the material and energy supply and living environment, by light, air, water, temperature and other organisms and other environments Factors and human limitations; the same time, biological life activities continue to influence, change the environment, but also affect human survival. In order to enable students to establish this dialectical perspective, I guided the students to make respectively the earthworm and sunlight, water, temperature and light-oriented beans, to the water test. Make students understand earthworm, bean individual dependence on the environment, experiments and observations of other common animals and plants, to determine the surrounding common living environment of animals and plants. Let