1 Food Chains and Food Webs-Low

Food Chains and Food Webs Written by Kira Freed

食物链和食物网作者:基拉·弗里德

Introduction Ana eats a breakfast of oatmeal, yogurt, and orange juice before going to school. The food she takes in will give her energy for learning, gym, and other morning activities. Where did the energy in her food come from? This book explores how living things get the energy and matter they need to survive. You will learn how one living thing depends on another and that all living things depend on the Sun's energy. You will also learn what happens when a food source is taken away.

安娜在上学前吃燕麦片、酸奶和橙汁的早餐。 她摄入的食物将为她的学习、健身和其他上午活动提供能量。 她食物中的能量从何而来? 这本书探讨了生物如何获得生存所需的能量和物质。 你将了解到一个生物是如何依赖另一个生物的，所有生物都依赖太阳的能量。 你还将了解当食物来源被拿走时会发生什么。

Producers and Consumers Living things are either producers or consumers. Producers produce, or make, their own food. Green plants are the main producers. They produce food by using the Sun's energy to combine water with a gas from the air. This process is photosynthesis. Without the Sun's energy and the producers that use it for photosynthesis, most living things on Earth would not survive. Consumers cannot make their own food. Instead they depend on producers for food. Consumers eat, or consume producers or other consumers, Producers and consumers depend on each other in many ways.

有生命的东西要么是生产者，要么是消费者。 生产者自己生产食物。 绿色植物是主要的生产者。 它们利用太阳的能量将水和空气中的气体结合起来生产食物。 这个过程就是光合作用。 如果没有太阳的能量和利用它进行光合作用的生产者，地球上的大多数生物将无法生存。 消费者不能自己做食物。 相反，他们依赖于生产者的食物。 消费者吃东西，或消费生产者或其他消费者。生产者和消费者在许多方面相互依赖。

Food Chains Food chains show how one living thing depends on another living thing for food, as each link in a paper chain depends on the one before and after it. Food chains also show how energy and matter move from producers to consumers. Since producers make food, they are the first link in a food chain.

食物链显示了一种生物如何依赖另一种生物来获取食物，就像纸链中的每一环都依赖于它之前和之后的一环一样。 食物链还展示了能量和物质是如何从生产者转移到消费者的。 由于生产者生产食物，他们是食物链的第一个环节。

A food chain has only one link for producers but many links for consumers. Primary consumers are living things that eat plants. They are the next link in a food chain. Grasshoppers and elephants are both primary consumers, or herbivores. Herbivores often have special body parts that help them get and use the energy stored in certain plant parts.

食物链对生产者来说只有一个环节，但对消费者来说有很多环节。 主要消费者是吃植物的生物。 它们是食物链的下一环。 蚱蜢和大象都是主要的消费者，或食草动物。 食草动物通常有特殊的身体部位，帮助他们获取和利用某些植物部位储存的能量。

To review, the first link in a food chain is the producers, or plants. The second link is primary consumers, or herbivores. The third link is secondary consumers—animals that eat the herbivores. These animals are carnivores, or meat eaters. When people think of carnivores, they often think of animals such as tigers and wolves. But other animals, such as insect- eating spiders and some bats, are also carnivores. So are penguins, bald eagles, and other fish eaters. What comes after primary consumers (which eat plants) and secondary consumers (which eat herbivores)? Many food chains also have tertiary consumers—carnivores that eat other carnivores. For example, let's say a mouse eats grass. Then a snake eats the mouse. A hawk that eats the snake is a tertiary consumer Word Wise Primary 1st Secondary 2nd Tertiary 3rd

回顾一下，食物链中的第一个环节是生产者，或植物。 第二个环节是主要消费者，也就是食草动物。 第三个环节是次要消费者——吃食草动物的动物。 这些动物是食肉动物。 当人们想到食肉动物时，他们通常会想到像老虎和狼这样的动物。 但其他动物，如食虫的蜘蛛和一些蝙蝠，也是食肉动物。 企鹅、秃鹰和其他吃鱼的动物也是如此。 在主要消费者(吃植物)和次要消费者(吃食草动物)之后是什么? 许多食物链也有第三级消费者——以其他食肉动物为食的食肉动物。 例如，假设一只老鼠在吃草。 然后蛇吃了老鼠。 吃蛇的鹰是三级消费者Word Wise小学1中学2小学3