Scott Foresman Science - Iredell- · PDF fileScott Foresman Science 5.6 Genre Comprehension Skill Text Features Science Content ... Effects of Industry 8 Acid rain can make

Scott Foresman Science 5.6
Genre Comprehension Skill Text Features Science Content
Nonfi ction Cause and Effect Labels
Captions
Sidebars
Glossary
Changing Ecosystems
ISBN 0-328-13933-5

1. Why are animals becoming endangered?
2. How do farms affect ecosystems?
3. What are some ways waterways can become polluted?
4. Purple loosestrife is a fl owered plant brought to the United States from Europe in the 1800s. It does not have any natural enemies in its new habitat and has spread throughout forty-nine of the fi fty states. What consequences do you think this has on its new ecosystem? Write to explain your answer. Use information from this book to support your ideas.
5. Cause and Effect Name a cause and effect of habitat loss.
What did you learn?Extended Vocabularyacid rainbedrockdeforestationdroughtendangeredfossil fuelsherbivorethermal pollution
Vocabulary
behavioral adaptationextinctinheritmutationpesticidestructural adaptation
Picture CreditsEvery effort has been made to secure permission and provide appropriate credit for photographic material. The publisher deeply regrets any omission and pledges to correct errors called to its attention in subsequent editions.
Photo locators denoted as follows: Top (T), Center (C), Bottom (B), Left (L), Right (R), Background (Bkgd).
8 (TR) Andre Maslennikov/Peter Arnold, Inc.; 14 Andrew Brown; Ecoscene/Corbis.
Scott Foresman/Dorling Kindersley would also like to thank: 1 NASA/DK Images.
Unless otherwise acknowledged, all photographs are the copyright of Dorling Kindersley, a division of Pearson.
ISBN: 0-328-13933-5
Copyright Pearson Education, Inc. All Rights Reserved. Printed in the United States of America. This publication is protected by Copyright, and permission should be obtained from the publisher prior to anyprohibited reproduction, storage in a retrieval system, or transmission in any form by any means, electronic,mechanical, photocopying, recording, or likewise. For information regarding permission(s), write toPermissions Department, Scott Foresman, 1900 East Lake Avenue, Glenview, Illinois 60025.
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There are many factors that affect ecosystems. Animals can change ecosystems in both positive and negative ways. Earthworms help by adding oxygen and nutrients to the soil. Insects, such as swarms of locusts, can cause major damage to crops. People change ecosystems too. Over time, people have moved plants and animals from their native ecosystems to new ones. Sometimes this changes the food chain of the ecosystem or takes away space from the native plants and animals.
The plants and animals in ecosystems can also adapt over time. Genes are passed down from each parent to their offspring and control such things as eye color and weight. Offspring will often resemble one or both of their parents. The ecosystem can even have an effect on what an organism looks like. The color of fl amingos, for instance, is a result of their diet. The kind of soil some fl owers grow in can affect their color.
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What You Already Know
Earthworms add nutrients and oxygen to soil.
A mutation sometimes occurs in the genes that are passed down. This change may end up helping the organism, for example, by making it blend in better with its surroundings. Or it may harm the organism by making it more prone to disease. Or the change may be neutral. If this mutation helps the organism adapt, it has a better chance for survival.
Some adaptations are structural adaptations. They are a change to a body part that helps the organism survive better.
Behavioral adaptations, also called instincts, are changes in behavior that help creatures survive. Offspring inherit these adaptations from their parents.
If a species does not adapt to changes in its ecosystem, it may become extinct. When this happens the species will never return.
Can you guess what causes ecosystems to change more quickly than anything else? The answer may surprise you: its humans. Keep reading to learn what kind of impact people are having on their environment.
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A tigers stripes are an adaptation that helps it blend into its surroundings.

Our world is constantly changing. One change to an ecosystem can have many consequences for its inhabitants. Some changes have natural causes, such as hurricanes and tornadoes. People, however, can also change ecosystems. Our actions can affect the habitats of plants and animals. Over time our technology has caused drastic change to our world.
In Europe during the 1760s, people began using machines to do work. Tasks that were once done by humans or with the help of animals were suddenly being done in less time with the help of machines. Coal was the main power source. But it made thick, black smoke, which clouded the air. Factories produced wastes that polluted streams, rivers, and lakes.
Advances in technology soon spread across the world. Better medical care allowed populations to grow. More farms were needed to feed the increasing numbers of people. Trees were cut down to make room for corn and rice fi elds as farms grew and grew. Animals that once relied on the forests lost their homes.
People still change ecosystems. For example, power stations, automobiles, and pesticides used by people cause pollution. Populations are growing faster than ever, requiring more land to be cleared for farming. Read on to learn more about how peoples actions affect ecosystems and the plants and animals that live in them.
Introduction
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Acid rain affects trees by damaging their leaves and polluting the soil that gives them nutrients.
Power stations burn fossil fuels that pollute the air.
Pesticides and fertilizers from farms can end up in nearby waterways, affecting the aquatic life.
Ships that carry oil sometimes leak or spill, causing the oil to end up in waterways.
Fumes from industry and automobile exhaust are higher in cities than rural areas.
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Why doesnt a polar bear get cold in the Arctic? How does a cactus survive in the desert without much water? Plants and animals have adapted to survive in a wide range of habitats. Many animals in the Arctic, for instance, have layers of blubber and thick fur to help them stay warm in the extreme cold. Desert plants, such as cactuses, are able to live without much water. They also absorb rainwater quickly and are able to store it for droughts, which are times when less water than normal is available.
Unfortunately, sometimes habitats are changed so much that it is hard for plants and animals to adapt. Many times, humans cause these changes.
Changing Habitats
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Deforestation has caused many animals and plants to lose their homes.
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Around the world, large numbers of trees are cut down by humans. This is called deforestation. Sometimes the wood is needed to make products such as lumber and paper. Other times, trees are cut down to clear the land for farming or building. Many animals use the trees for homes or hide in them to escape predators.
A similar problem is happening in the rainforests, where there is a wide variety of plants and animals. Animals rely on the plants for food and shelter. Humans also rely on many of the plants for medicines, food, and other products.
Even in the ocean, habitats are being destroyed. Coral reefs are a special saltwater habitat created by coral, an unusual animal related to the jellyfi sh. Coral reefs are home to many different ocean plants and animals. Pollution and higher sea temperatures are hurting coral populations. This affects not only the coral, but all of the other animals and the plants that live there.
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The saguaro cactus adapts well to its dry desert habitat.
Coral reefs face threats from pollution and warmer temperatures.
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Since industry fi rst began, pollution has been a problem. Factories and power stations need fuel in order to produce energy. Many run on fossil fuels, such as coal, oil, or natural gas. When burned, these fuels can cause air pollution. This can result in acid rain, which contaminates water. Acid rain can cause damage to the outsides of buildings and be unhealthy for animals to drink. Acid rain seeps down into the soil too. This can cause the acidity of the soil to change. Then aluminum may be released into lakes and rivers. Aluminum is very dangerous for fi sh and other marine animals. It can also hurt the predators of these animals.
Effects of Industry
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Acid rain can make trees unhealthy.
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Some factories and power stations also produce unwanted heat. They reduce this heat with cold water and then pump the water into rivers. This can cause serious problems for the environment. Th

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Scott Foresman Science - Iredell- · PDF fileScott Foresman Science 5.6 Genre Comprehension Skill Text Features Science Content ... Effects of Industry 8 Acid rain can make