叶子是由叶及开始变黄的吗?

• 作 者: 张泓婧 周忆南 陈颖文
• 机 构: 花家地实验小学五(7)班,花家地实验小学,
• 出 处: 小学科学
• 发表日期: 2011年10期
• 关键词: 选题背景 扁豆叶 实验记录 叶缘 研究方法 白菜叶 花草树木 知识解释 小叶黄杨 网络搜索

一、选题背景秋天来了,有些树的叶子慢慢开始变成黄色或者红色,我们注意到有些树的叶子慢慢变黄,比如杨树、柳树、银杏树;有些树的叶子慢慢变红,比如枫树。我们很是好奇:为什么秋天有的叶子会变色而且大多都是变成黄色?植物叶子到底是从哪里开始变黄的呢?二、研究方法查询资料,观察各种植物,尤其以绿叶植物为主,查阅有关绿叶变黄的网

First, the background of the topic Autumn is coming, and some of the tree leaves slowly begin to turn yellow or red, we noticed that some of the tree leaves slowly yellow, such as poplar, willow, ginkgo tree; some tree leaves slowly change Red, such as maple. We are very curious: why some of the autumn leaves will change color and most of them turn yellow? Plant leaves in the end is where it began to turn yellow? Second, research methods for information, observe a variety of plants, especially green plants , Check the yellowing of the network of green leaves