3 Food Chains and Food Webs-High

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 sits down at the table for a breakfast of oatmeal, yogurt, and orange juice before going to school. The food she takes in will provide energy for learning, gym, and her other morning activities. Where did the energy in her oatmeal, yogurt, and orange juice 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 ultimately all living things depend on energy from the Sun. You will also learn what happens when a food source is taken away.

安娜在上学前坐下来吃早餐，吃燕麦片、酸奶和橙汁。 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。 燕麦、酸奶和橙汁中的能量从何而来? 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，最终所有生物都依赖于来自太阳的能量。 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 make their own food. Green plants are the major producers. They produce food by using energy from the Sun to combine water with a gas from the air. This process is called photosynthesis. Without energy from the Sun and the producers that use it for photosynthesis, most living things on Earth would not survive. Consumers are living things that cannot make their own food. Instead, they depend on producers for food. For example, grass is a producer. When a cow munches on the grass, the cow is a consumer. The cow cannot make food from sunlight. Consumers eat, or consume, producers or other consumers. The cow that munched on the grass was growing and making milk. When you sit down to drink a glass of milk or eat a hamburger that comes from a cow, you are a consumer, too. Producers and consumers depend on each other in complex relationships. Let's look into some of these relationships.

有生命的东西要么是生产者，要么是消费者。 生产者自己制作食物。 绿色植物是主要的生产者。 它们利用来自太阳的能量将水和空气中的气体结合起来生产食物。 这个过程叫做光合作用。 如果没有来自太阳的能量以及利用这些能量进行光合作用的生产者，地球上的大多数生物将无法生存。 消费者是不能自己制造食物的生物。 相反，他们依靠生产者提供食物。 例如，草是生产者。 当牛在吃草时，它就是一个消费者。 牛不能用阳光制造食物。 消费者吃，或消费，生产者或其他消费者。 吃草的那头牛正在生长，正在产奶。 当你坐下来喝一杯牛奶或吃一个牛肉汉堡时，你也是一个消费者。 生产者和消费者在复杂的关系中相互依赖。 让我们来看看其中的一些关系。

Food Chains Scientists often use food chains to illustrate how one living thing depends on another living thing and how energy and matter move from producers to consumers. Food chains can be short or fairly long. Since producers make food, they are the first link in a food chain. A food chain has only one link for producers but many links for consumers. Primary consumers are organisms that eat producers. They are the next link in the food chain. Primary consumers, called herbivores, can be as small as a grasshopper or as large as an elephant. Special body parts help many herbivores break apart tough plant material so they can get the energy stored in certain plant parts. Parrots have tough beaks that can crack open the outer cases of tropical fruits and nuts. Elephants have special teeth to grind tree bark.

科学家经常用食物链来说明一种生物如何依赖于另一种生物，以及能量和物质如何从生产者转移到消费者。 食物链可以很短，也可以很长。 由于生产者生产食物，他们是食物链的第一个环节。 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。 主要消费者是吃生产者的生物。 它们是食物链的下一环。 主要的消费者被称为食草动物，可以小到蚱蜢，也可以大到大象。 特殊的身体部位可以帮助许多食草动物分解坚硬的植物材料，这样它们就可以把能量储存在某些植物部位。 鹦鹉有坚硬的喙，可以打开热带水果和坚果的外壳。 大象有特殊的牙齿来磨树皮。

Even with special body parts, many herbivores must spend an enormous amount of time eating to obtain enough energy to stay alive. For example, giant pandas must eat for about sixteen hours each day to get enough nutrients and energy from their diet of bamboo leaves and stems.

即使有特殊的身体部位，许多食草动物也必须花费大量的时间进食以获得足够的能量来维持生命。 例如，大熊猫每天必须吃大约16个小时，才能从竹子的叶子和茎中获得足够的营养和能量。

To review, the first link in a food chain is the producers, or plants. The second link is the primary consumers, or herbivores. The third link in a food chain is secondary consumers— animals that feed on 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, bats, and anteaters, are also carnivores. So are penguins, bald eagles, and other fish eaters. Can you guess the next link in a food chain? After primary consumers (which eat plants) and secondary consumers (which eat herbivores), many food chains have tertiary consumers— animals that eat other carnivores. For example, let's say a mouse (primary consumer/herbivore) eats grass, and a snake (secondary consumer/ carnivore) eats the mouse. A hawk that eats the snake is a tertiary consumer— a carnivore that eats another carnivore. 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。 第二个环节是主要的消费者，也就是食草动物。 食物链中的第三个环节是二级消费者——以食草动物为食的动物。 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，比如以昆虫为食的蜘蛛、蝙蝠和食蚁兽，也是食肉动物。 企鹅、秃鹰和其他吃鱼的动物也是如此。 你能猜到食物链的下一个环节是什么吗? 在主要消费者(吃植物)和次要消费者(吃食草动物)之后，许多食物链还有第三消费者——吃其他食肉动物的动物。 例如，假设一只老鼠(主要消费者/食草动物)吃草，而一条蛇(次要消费者/食肉动物)吃老鼠。 鹰吃掉蛇是第三消费者——食肉动物吃掉另一种食肉动物。 文字智慧小学，第一，中学，第二，第三，第三