How Do Plants Get Food

How Do Plants Get Food? by Barbara J. Davis Science and Curriculum Consultant: Debra Voege, M.A., Science Curriculum Resource Teacher

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Science in the Real World: How Do Plants Get Food? Copyright © 2010 by Infobase Publishing All rights reserved. No part of this book may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage or retrieval systems, without permission in writing from the publisher. For information contact: Chelsea Clubhouse An imprint of Chelsea House Publishers 132 West 31st Street New York NY 10001 Library of Congress Cataloging-in-Publication Data Davis, Barbara J., 1952 How do plants get food? / by Barbara J. Davis; science and curriculum consultant, Debra Voege. p. cm. — (Science in the real world) Includes index. ISBN 978-1-60413-468-1 1. Photosynthesis—Juvenile literature. I. Title. II. Series. QK882.D38 2010 572’.42—dc22 2009013075 Chelsea Clubhouse books are available at special discounts when purchased in bulk quantities for businesses, associations, institutions, or sales promotions. Please call our Special Sales Department in New York at (212) 967-8800 or (800) 322-8755. You can find Chelsea Clubhouse on the World Wide Web at http://www.chelseahouse.com Developed for Chelsea House by RJF Publishing LLC (www.RJFpublishing.com) Text and cover design by Tammy West/Westgraphix LLC Illustrations by Spectrum Creative Inc. Photo research by Edward A. Thomas Index by Nila Glikin Photo Credits: 4, 17: Oxford Scientific/Photolibrary; 5, 16, 20, 21, 28: iStockphoto; 8: Maxine Adcock/ Photolibrary; 14: © Gunter Marx/Alamy; 15: Ingo Arndt/Minden Pictures; 18: Michael Durham/Minden Pictures; 19: Larry Minden/Minden Pictures; 27: Jose Luis Pelaez Inc./Photolibrary; 29: Vertical Farm Project: “The Living Skyscraper: Farming the Urban Skyline” by Blake Kurasek. Printed and bound in the United States of America Bang RJF 10 9 8 7 6 5 4 3 2 1 This book is printed on acid-free paper. All links and Web addresses were checked and verified to be correct at the time of publication. Because of the dynamic nature of the Web, some addresses and links may have changed since publication and may no longer be valid.

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Table of Contents Food and Life............................................................ 4 Food Factory............................................................. 6 Plant Parts: Roots and Stems.................................. 8 Plant Parts: Leaves................................................. 10 The Food-Making Process . ................................... 12 Plants That Steal.................................................... 14 Animal-Eating Plants.............................................. 16 Plants and Ecosystems........................................... 18 Producers and Consumers.................................... 20 Food Chains............................................................ 22 Food Webs.............................................................. 24 Energy Pyramids.................................................... 26 Helping Plants Help People.................................. 28 Glossary.................................................................. 30 To Learn More........................................................ 31 Index....................................................................... 32 Words that are defined in the Glossary are in bold type the first time they appear in the text. 5

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Food and Life

Squirrels eat the nuts and seeds of trees and other plants.

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hink about the last time you were at a park. How many different types of living things did you see? Perhaps you sat on the grass and watched an ant crawl over your hand. You might have seen squirrels running along a tree branch. Maybe birds flew overhead. What you might not realize is that you and all the other living things you saw have something in common. Every living thing needs food to survive. Living things are called organisms. Food provides the materials that all organisms must have to grow and to be healthy. There are many sources of food in the world. Animal Food and Plant Food Some animals get food by eating other animals. Some birds eat worms

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and insects. Other animals get food by eating plants. The squirrels in the park might have been looking for acorns ready to fall from the tree. (Acorns are the nuts made by oak trees.) For almost all animals, getting food is usually a matter of eating another organism. But plants are different. For almost all plants, getting food does not mean eating another organism. Most plants can make their own food. DID YOU KNOW

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Plant Facts Have you ever wondered how many types of plants there are in the world? Scientists believe there are more than 270,000 different kinds of plants. The water duckweed plant is the smallest plant that has flowers or makes fruit. Water duckweed is less than a thousandth of an inch long (less than 0.001 inches, or 25 micrometers). Giant sequoia trees (see photo above) are among the largest plants in the world. Some grow to 385 feet (117 meters) tall. 5

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Food Factory

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factory is a place where a product is made. A plant is something like a factory. The product of a plant factory is food for the plant. To understand how a plant factory works, you need to know a little about the smallest part of any plant—the cell. Some plants have only a few cells. Other plants, though, have many millions of cells. Plant cells are so small they can be seen only with a microscope. Each plant cell has certain parts that have special jobs to do. The Parts of a Plant Cell

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Plant cells have a special structure around them called a cell wall. This wall is strong. It provides support and protection for the cell. The cell membrane is like a thin inner wall next to the stronger cell wall. The cell membrane’s main job is to allow needed water and nutrients into the plant cell. Within the cell is the nucleus. The nucleus guides most of the cell’s

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Parts of a Plant Cell activities. It’s Mitochondria Cell Wall Cell almost like the Membrane brain of the cell. Cytoplasm Vacuoles There are Nucleus other structures inside a plant cell. Chloroplasts Vacuoles are sacs that store water and other materials Each part of a plant cell has a special job. that the plant cell needs. The mitochondria The chloroplasts hold are structures in the cell where energy for chlorophyll, which the cell is stored for later use. the plant needs to make food. Many, but not all, plant cells have green, oval-shaped parts called chloroplasts. Chloroplasts have a green material that is called chlorophyll. A plant cell must have chlorophyll in order to make food for the plant. The cytoplasm is a jelly-like material that is mainly water. The nucleus, vacuoles, mitochondria, and chloroplasts lie in the cytoplasm. DID YOU KNOW

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Grass Stains If you have ever rolled around in the grass, you probably got green streaks on your clothes. Those streaks are chlorophyll. The weight of your body crushes the grass leaves and the cells that make up the leaves. The liquid-like chlorophyll that leaks out of the crushed cells is easily absorbed by clothing, leaving what people call “grass stains.” 7

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Plant Parts: Roots and Stems

Three important parts of many types of plants are the roots, the stem, and the leaves.

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ll plant cells have the same basic parts. However, certain types of cells can specialize—that is, they do a certain type of job for the plant. Some cells will have the job of helping the plant stay upright. Other cells will specialize in making food. Specialized plant cells form the main structures in a group of plants called vascular plants. These are plants that have vessels, or tubes, that carry water and other materials throughout the plant. Many common plants are vascular plants, including trees, bushes, and most flowering plants.

Parts of a Plant Leaves

Stem Roots

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Below and Above the Ground A vascular plant’s roots are usually underneath the ground. The roots have two main jobs. One job is to hold the plant in the soil. The soil is the source of the water the plant needs to make food. There are also nutrients in the soil that the plant needs to stay healthy. The other job of the roots is to actually absorb water and nutrients from the soil. Tubes in the roots carry the absorbed water and nutrients to the stem. Stems usually grow above the ground and support the plant. They also allow the leaves of the plant to reach sunlight, so that the plant can make food. Like roots, the stems of vascular plants carry water and nutrients to other parts of the plant. DID YOU KNOW Root Snacks

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A taproot is a strong root that reaches deep into the soil. Besides absorbing water and nutrients, some taproots also store food for the plant. This makes these particular taproots a good healthful food for people, too. Carrots, beets, radishes, and sweet potatoes are all examples of taproots. The photo here shows some carrots just pulled out of the ground. 9

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Plant Parts: Leaves

Most leaves have different layers. One of the layers has cells with chloroplasts for making food.

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he leaves of a plant have one main job—to make food for the plant. Most leaves have several layers of cells. Each layer has a special job. The outer layer is called the epidermis. The epidermis on the side of the leaf that faces up usually has a coating of wax to help keep water in the leaf. The underside of the leaf, or the lower epidermis, has small openings called stomata. The stomata open and close at different times during the day and night. When the stomata are open, they allow

Inside a Leaf Upper Epidermis with Waxy Coating

Cells with Chloroplasts That Make Food

Cells That Hold Water and Other Materials

Vein

Lower Epidermis Stomata

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carbon dioxide into the leaf. Carbon dioxide is a gas that is found in the air. It is one of the materials the leaf needs to make food. Sometimes the stomata close. This helps keep water in the leaf. Where the Food Is Made A layer of cells that have chloroplasts is found just below the upper epidermis of the leaf. Most of the food-making in the leaf takes place in this layer. Remember that the chloroplasts have chlorophyll. Along with water, light, and carbon dioxide, a plant cell must have chlorophyll to make food. A spongy layer of cells just above the lower epidermis has spaces that hold the basic materials, like water, that the plant will need to make its food. The leaf surface also has a series of veins. These veins connect to the tubes in the stem that bring up water and nutrients from the soil. DID YOU KNOW

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Nonvascular Plants Nonvascular plants are plants without tubes. They rely on other means to carry water and food throughout the plant. Instead of roots, nonvascular plants have very fine root-like parts that hold them to soil. These plants are usually small and low to the ground. Water and nutrients are absorbed directly into leaf-like parts of the plant, like a sponge. The food made in the leaf-like parts moves from cell to cell within the plant. Moss is an example of a nonvascular plant. 11

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The FoodMaking Process

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In photosynthesis, a plant uses sunlight, water, carbon dioxide, and its own chlorophyll to make its food.

lants make their own food through a process called photosynthesis. Photosynthesis begins when light strikes the plant’s leaves. The chlorophyll in the chloroplasts captures energy from sunlight. This starts a chemical change that makes the water in the leaf split into its two basic parts. These parts are the gases oxygen and hydrogen. The oxygen (which is not needed by the plant) goes out of the plant through the leaves and enters the air.

How Photosynthesis Works Sunlight strikes the chlorophyll in the chloroplasts

Oxygen goes out of the leaf into the air

Carbon dioxide from the air enters the leaf

Water is carried up from the roots

In the chloroplasts, sunlight splits the water into hydrogen and oxygen, and the hydrogen combines with carbon dioxide to make sugar, which is the plant’s food

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Sugar for Food Carbon dioxide enters the leaf through the stomata. In a series of steps, the carbon dioxide combines with the hydrogen to create a type of sugar called glucose. This sugar is the plant’s food. It gives the plant the energy it needs to grow and stay healthy. Glucose is also in the white sugar you may use on your cereal. White sugar is also called “table sugar.” It is a combination of glucose and another type of sugar called fructose. In a plant, some of the sugar stays in the leaves. Some is moved through the tubes in the plant to the cells in the stem. The stem cells keep some of the sugar, and the rest is carried down to the cells of the roots. If the plant has fruit, some sugar goes there, too. The plant uses some of the sugar it makes right away. The rest is changed into a form of energy that is stored in the plant cells’ mitochondria. This energy can be used later when the plant needs it. DID YOU KNOW

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Fresh Air Plants are putting oxygen into the air as part of photosynthesis. People and other animals breathe in oxygen. When they exhale, or breathe out, they put carbon dioxide into the air. Carbon dioxide is just what plants need for their photosynthesis. This is just one of the many ways in which plants and other living things depend upon each other for life. 13

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Plants That Steal

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ll green plants can make their own food through photosynthesis. These plants have chloroplasts and chlorophyll, which are the things that make the plant green. Some plants don’t have a lot of chloroplasts and chlorophyll. They can make some of their food but not enough to survive. These plants use other means to add to their food supply. Mistletoe is a plant that has light green leaves and white berries. It attaches itself to certain types of trees, such as oak or pine trees. Mistletoe can make some of its food from

The witches’ hair plant gets all of its food from the bush or tree it attaches itself to.

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photosynthesis. It takes the rest of the water and nutrients that it needs from the tree. It is one of a group of plants called parasites. A parasite plant attaches itself to another plant and “steals” water or other nutrients. Living Completely Off Other Plants Some parasite plants, like mistletoe, make some of their own food. Other parasite plants, like witches’ hair, or dodder, have no chloroplasts at all. They cannot make any of their own food. These plants live entirely by taking food from other plants. Witches’ hair is common in California. It looks like long orange strings, and it wraps itself around the stems of bushes or trees and takes water and nutrients from the stems.

DID YOU KNOW

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The Corpse Flower The corpse flower, which grows in the Asian country of Indonesia, is the world’s largest flower (see photo above). One type can grow as large as 3 feet (almost 1 meter) across. The corpse flower is also a parasite. It cannot make its own food and depends totally on the vine it attaches itself to in order to live. The corpse flower gets its name because it gives off an odor like rotting flesh. 15

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AnimalEating Plants

A Venus flytrap leaf can close to trap an insect and turn it into a meal for the plant.

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ome plants that cannot make all of their own food don’t get the rest by stealing from other plants. They get it by trapping animals. These “meat-eating” plants are called carnivorous plants. Scientists have identified more than 600 different types of carnivorous plants around the world. Some carnivorous plants have colorful tubes that tempt insects into the plant. Once inside, the insect is trapped by sticky material inside the tubes. Then, a special fluid dissolves the insect and turns it into the plant’s food. There are carnivorous plants that look quite ordinary, with a pretty flower on a stalk. However, the stalk has fine hairs coated with sticky material that trap insects that land. Again, a special fluid then dissolves the insects.

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Venus Flytrap The Venus flytrap is a well-known carnivorous plant. This plant has green parts and can make some of its own food. The rest of what it needs it gets from trapping flies. The leaves of a Venus flytrap open wide, like a mouth. There are short, stiff hairs surrounding the leaf. When an insect touches one of these hairs, it signals the leaf to close. The trapped insect cannot get out, and it is slowly dissolved by special juices in the leaf.

This bladderwort has trapped its prey.

DID YOU KNOW

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Fast Food Bladderworts are carnivorous plants that can be found all over the world. They get their name because the plants have little bags, or bladders, hanging from them. Bladderworts live mainly in areas where there is a lot of water. The plant’s bladders are underground in very wet soil or in the water of rivers and lakes. The bladders act as traps for their prey, which can be anything from tiny insects to larger worms. The bladder has a type of trap door. When the prey bumps up against it, the door opens and water rushes in, carrying the prey with it. This happens in much less than a second! Inside, special juices do the work of dissolving the prey. 17

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Plants and Ecosystems

This frog about to take a swim is part of a pond ecosystem.

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ll the world’s plants live in some type of ecosystem. An ecosystem is formed by all the living and nonliving things in an area. An ecosystem’s living things include plants and animals. Nonliving things include air, water, and soil. The world is made up of many different types of ecosystems. An ecosystem can be as small as a puddle of water. You would need a microscope to see the very tiny plants and animals living there. A pond ecosystem might include plants like cattails and water lilies. This

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ecosystem would also have flying insects, such as mosquitoes, as well as frogs and fish. There would also likely be birds and raccoons living around the pond. Life in the Desert It might be hard to think of a desert as an ecosystem with living things—deserts can be so dry and hot, and they can seem so barren. In fact, desert ecosystems often have a wide variety of plants and animals. Desert plants may include cactus and bushes that grow low to the ground. Desert animals such as lizards, jackrabbits, and roadrunners may live among the plants. Large desert spiders may also call the ecosystem home.

The tortoise and the Mojave desertrue shrub it was using for some shade are both part of a desert ecosystem.

DID YOU KNOW

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Different but the Same Even though ecosystems can be very different, they all have one thing in common. An ecosystem’s plants and animals depend on each other to survive. The living things within an ecosystem need energy for every part of life. In most cases, that energy will first come from the plants that are living there. 19

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Producers and Consumers

These deer get the energy they need to live from the grass they eat.

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ll ecosystems have living things called producers. The word “produce” means make. Most plants are producers because they make their own food through photosynthesis. Some of the food the plant makes is stored in the plant. Later, the plant can use this stored food to get the energy it needs to live, grow, and make more food. A plant’s stored food is like stored energy. Other living things can also get and use the plant’s stored energy. They can do this by eating the plant. Living things that eat other living things are called consumers. Eat is one meaning of the word “consume.” Animals are one type of consumer because they eat plants or other animals to get the energy they need to live. Some animals like cows or deer eat only plants. When these animals eat grass, they

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are getting some of the energy stored in the blades of grass. Animals like wolves and lions eat other animals. They get the energy to live from the animals they eat. What Are Decomposers? Decomposers are a special type of consumer. Bacteria, fungi, and earthworms are all decomposers. Bacteria eat the remains of dead plants and animals. Fungi and earthworms consume the remains of dead plants. These decomposers break down the remains into nutrients. They use some of the nutrients, and other nutrients go back into the soil. This is helpful to plants. Plants use these nutrients when they are taken up by the plants’ roots. DID YOU KNOW

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Are Mushrooms Plants? Many people believe that mushrooms are plants. They aren’t. Mushrooms are actually fungi. They are also decomposers. Like other fungi, mushrooms do not have chloroplasts in their cells. Without chloroplasts, the mushroom cannot make its own food. Instead, it breaks down the remains of dead plants into nutrients. 21

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Food Chains

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ood energy in an ecosystem is passed from one living thing to another. A food chain describes a single path through which that food energy is passed. The process is called a “chain” because each organism in the chain is linked, or joined, to another organism. The plants and animals are linked by the way food energy is being passed from one to another. The organisms depend on one another to live. All food chains begin with a producer plant. Let’s say a food chain begins with a carrot plant. Remember that the root of this plant is a plump carrot storing food made by the plant. First, the carrot is eaten by a consumer—a rabbit. When that happens, some of the food energy from the carrot is passed to the rabbit. Moving up the Chain In most ecosystems, the first consumer is probably eaten by another consumer. Perhaps a fox catches 22

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A Food Chain

This food chain starts the rabbit and eats it. The fox gets food enwith a producer ergy from the rabbit. Sometimes, still another plant—a carrot—and ends with a consumer is part of the food chain. Maybe a mountain lion. mountain lion eats the fox. As with every other part of the chain, the mountain lion gets some food energy from the fox. DID YOU KNOW

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Producers in the Dark No sunlight makes it to the bottom of the ocean. This means that plants can’t grow there. The bottom of the deep ocean is full of living things, though. How can this be without a plant to begin the food chain? There may not be plants, but there are producers. These are a certain kind of bacteria that use a chemical that comes out of cracks on the sea floor. The bacteria combine the chemical with water and carbon dioxide to make types of sugar. These sugars are in the bacteria’s bodies. The bacteria become food for another organism, and the food chain begins. 23

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Food Webs

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ost ecosystems have several— or even many—food chains. These food chains are connected to each other. A food web is all of the connected, or linked, food chains in an ecosystem. A food chain shows one path through which food energy is passed from one living thing to another. A food web shows a number of possible food energy paths. Chains Form a Web Most animals eat more than one type of food. For example, the rabbit that ate the carrot may also eat grass seeds. Birds also eat grass seeds. The grass is part of more than one food chain. The same fox that ate the rabbit might also eat the bird. The fox may also eat a chipmunk that eats acorns. The fox is part of several different food chains. The mountain lion that ate the fox might also eat a rabbit. An owl might also be in this food web, eating the chipmunk, for example.

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A Food Web

This food web has Food webs exist in the sea. The many different pathproducers in most ocean food webs are ways in which food energy travels from tiny organisms called phytoplankton. They one living thing to make food through photosynthesis. Algae another. are phytoplankton. Other living things called zooplankton eat the phytoplankton. Small fish eat zooplankton. Larger fish eat smaller fish and also eat zooplankton. Sharks may eat larger fish and also smaller fish. Sea birds that eat fish are also part of the food web. DID YOU KNOW

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A World of Food Webs Food webs exist wherever there are things that eat other things. Whether the ecosystem is an ocean, a desert, a pond, or a forest, food webs exist. 25

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Energy Pyramids

A food energy pyramid needs to have many producer plants at the bottom to support the animals that are consumers.

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n energy pyramid shows how much actual food energy is passed along at each stage of the food chain. A plant uses most of the food energy it makes to live and grow. Only the food energy stored to be used later can move to another living thing if the plant is eaten. Only about 10 percent of the food energy made by the carrot plant gets to the rabbit that eats the carrot. The rabbit also uses most of the energy it gets to live and grow. Only

A Food Energy Pyramid

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about 10 percent of the food energy the rabbit takes in is passed on to the fox that eats the rabbit. This low rate of energy transfer continues all the way up the food chain. Consumers at the Top The consumer at the top of the energy pyramid has to eat many other living things to get enough food energy to live. This is why most food chains have only three or four levels. The producers at the bottom of the energy pyramid support the energy needs of all the levels above them. If there are too many top-level consumers, there would have to be a huge number of producers to support them. DID YOU KNOW

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Where People Fit into the Energy Pyramid You have a choice of where you fit into an energy pyramid. When you bite into a juicy hamburger, you are what is called a second-level consumer. You get your food energy from an animal (a cow) that ate plants (grass). When you eat vegetables, you are a first-level consumer. You get your food energy directly from the plants that made it. 27

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Helping Plants Help People

An acre of land planted with wheat can provide more food than the same amount of land when it is used to feed cows that are raised for food.

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he ability of plants to make food is important for almost all living things. Plants are usually the first level in any food chain. There are many things that people do, though, that harm the ecosystems where plants grow or that use up too many plants. There are also some things that people can do to help use resources more efficiently. Eating More Foods from Plants One is to eat more vegetables, fruits, and foods made from wheat and

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other grains. The beef people eat comes from cows that need to eat a lot of grass. If someone ate only meat, that person would need the meat from about ten cows each year. Ten cows need about 5 acres (2 hectares) of grass a year. If someone ate only food made from grains, just 1 acre (0.4 hectares) of wheat would provide enough food for a year. Of course, people don’t eat only beef or only food made from wheat. But the more a person eats foods from plants, the less land that is needed to grow that person’s food.

This model shows what a vertical farm building in a city might look like.

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The Vertical Farm Project Some experts believe that, by the year 2050, the world may have more than 9 billion people. (It has fewer than 7 billion now.) Some scientists are concerned that there may not be enough farmland to feed this larger population. One scientist’s answer to this problem is called the Vertical Farm Project. The idea is to put up specially designed tall buildings in which food plants can be grown. The buildings can be in cities, and the food can help feed the world’s growing number of people. 29

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Glossary bacteria—Types of tiny livings thing that have one cell. carnivorous—Meat-eating. cell membrane—A thin, flexible sheet of material that surrounds the inside of a cell. cell wall—The strong outermost layer of a plant cell that gives it support. chlorophyll—A green-colored material inside some plant cells that captures energy from sunlight that is used in photosynthesis. chloroplast—A structure inside some plant cells that holds the plant’s chlorophyll. cytoplasm—A jelly-like material inside a cell in which the nucleus and other parts of the cell are found. decomposer—A living thing that breaks down dead plants or animals into nutrients and other materials. ecosystem—An area in which a group of plants and animals live that depend on one another for survival. food chain—A pathway by which food energy is passed directly from one living thing to another. food web—A group of interconnected food chains.

fungi—Types of living things that live by taking nutrients from dead plants. glucose—A type of sugar. It is the type produced in plants during the process of photosynthesis. grains—Plants such as wheat, corn, and rice that are major sources of food energy. mitochondria—Structures in cells where food energy is stored for later use. nucleus—A structure inside a cell that controls the activities of the cell. nutrients—Substances that give a living thing the materials it needs to grow and be healthy. organism—A living thing. parasite—A living thing that lives on or in another living thing and gets what it needs to live from that other living thing. photosynthesis—The process by which a plant makes its own food. stomata—Tiny openings in the outer layer of a plant leaf. vacuoles—Sacs inside a cell that hold water and other things the cell needs.

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To Learn More Read these books: Kalman, Bobbie. Photosynthesis: Changing Sunlight into Food. New York: Crabtree Publishing, 2005. Latham, Donna. Respiration and Photosynthesis. Chicago: Raintree Publishing, 2009. Pollock, Steve. Ecology. New York: Dorling Kindersley, 2005.

Look up these Web sites: Brain Pop—Our Fragile Environment http://www.brainpop.com/science/ourfragileenvironment Environmental Literacy Council http://www.enviroliteracy.org/students-index.php Full-Time Exploring Science and Technology—Photosynthesis http://www.ftexploring.com/photosyn/photosynth.html Science News for Kids—Plants http://www.sciencenewsforkids.org/pages/search.asp?catid=26

Key Internet search terms: ecosystems, food chains, photosynthesis, plants

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Index Air 12, 13, 18 Animal-eating plants 16–17 Animals 18–19, 20–21, 22–23, 24–25, 26–27 Bacteria 21, 23 Birds 4, 19, 24, 25 Bladderworts 17 Carbon dioxide 11, 13 Carnivorous plants see Animal-eating plants Cell structure in plants 6–7 Chloroplasts and chlorophyll 7, 10, 11, 14 Corpse flower 15 Cytoplasm 7 Decomposers 21 Desert 19 Ecosystems 18–19 Energy storing and transfer 7, 19, 20, 23, 24, 26–27 Epidermis (leaf) 10 Fish 25 Food chains and food webs 22–25 Fruits and vegetables 28 Fungi 21 Grains 28–29 Hydrogen 12, 13 Insects 16–17 Leaves 8, 10–11

Making of plant food 7, 10–11, 12–13 Mistletoe 14 Mitochondria 7, 12 Mushrooms 21 Nonvascular plants 11 Nucleus (plant cells) 6–7 Number of plants 5 Ocean 23, 25 Oxygen 12, 13 Parasite plants 14–15 Parts of plants 8–9, 10–11 Photosynthesis 12–13, 25 Phytoplankton 25 Roots (plants) 8–9 Soil 9, 11, 18 Squirrels 4, 5 Stems (plants) 8–9 Stomata 10 Sugar 13, 23 Sunlight 9, 12, 23 Taproot 9 Trees 5, 8, 14 Vacuoles 7 Vascular plants 8–9 Venus flytrap 17 Vertical Farm Project 29 Water 9, 11, 12, 15, 17, 18 Zooplankton 25

About the Author Barbara J. Davis has written books on science topics for kids for more than fifteen years. She has published books on ecosystems and biomes, as well as on earth science subjects. 32

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