Pri ma ry 2 Textbook
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Aligned to the Next Generation Science Standards
Pri ma ry 2 Textbook
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The 5E Model – Guided Inquiry The Let’s Do Science series is based on the Biological Sciences Curriculum Study (BSCS) 5E teaching and learning instructional model. The 5E model is centered on the idea that students understand science concepts best by using prior knowledge to pose questions and find answers through guided inquiry. This hands-on approach, integrated with engineering and design skills, has students learn science by doing science. Teachers guide the learning process and are able to assess student performance by evaluating student explanations and the application of newly acquired knowledge and skills.
Engage
The Engage phase of the 5E model provides students with the opportunity to demonstrate their prior knowledge and understanding of the topic or concept. Students are presented with an activity or question which serves to motivate and engage students as they begin the lesson. Teachers identify and correct any misconceptions and gather data from students which will guide informed teaching and learning.
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Essential to stimulating and engaging students is the use of mixed media such as colorful photos, illustrations and diagrams found throughout the textbooks and activity books. Let’s Do Science also includes extensive digital resources such as narrated videos, interactive lessons, virtual labs, slideshows and more.
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Explore
This phase encourages exploration of concepts and skills through handson activities and investigations. Students are encouraged to work together and apply various process skills while gaining concrete, shared learning experiences. These experiences provide a foundation for which students can refer to while building their knowledge of new concepts. This studentcentered phase comes before formal explanations and definitions of the concept which are presented by the teacher.
Explain
This phase follows the exploration phase and is more teacher-directed. Students are initially encouraged to draw on their learning experiences and demonstrate their understanding of the concept through explanations and discussion. After the students have had the opportunity to demonstrate their understanding of the concept, the teacher then introduces formal definitions and scientific explanations. The teacher also clarifies any misconceptions that may have emerged during the Explore phase.
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Elaborate
In the Elaborate phase, students refine and consolidate their acquired knowledge and skills. Opportunities are provided for students to further apply their knowledge and skills to new situations in order to broaden and deepen their understanding of the concept. Students may conduct additional investigations, share information and ideas, or apply their knowledge and skills to other disciplines.
Evaluate
This final phase includes both formal and informal assessments. These can include concept maps, physical models, journals as well as more traditional forms of summative assessment such as quizzes or writing assessments. Students are encouraged to review and reflect on their own learning, and on their newly acquired knowledge, understanding and skills.
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Let’s Do Science Let’s Do Science is based on the United States Next Generation Science Standards (NGSS). The series consists of full-color textbooks and full-color activity books for Grades K to 6.
Birds
Birds are anim covered in feat legs and two w their wings to f
Birds ha shapes shape o bird to g
Let’s Do Science engages students with a highly visual presentation of the disciplinary core ideas in the textbooks and places an emphasis on applying scientific knowledge using NGSS practices through numerous scientific investigations. Let’s Do Science sees engineering as an essential element of science education and as such is tightly integrated into both the textbooks and activity books. The Let’s Do Science textbooks include the following features:
Think Deeply
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Topic-related questions for group discussion aimed at deepening students’ understanding of the topic.
In the Field
If you love plants of all shapes and sizes, you might want to be a horticulturist. A horticulturist is a scientist that specializes in growing plants for people to use.
Horticulturists can also use their knowledge of plants and soil to help manage and protect natural areas like parklands or nature reserves. 30
Horticulturists use their knowledge of plants to help farmers improve the fruits, flowers and vegetables they grow.
Engineer It! Goes beyond inquiry by encouraging students to design, model and build to engineer solutions to defined problems.
In the Field Inspirational sciencerelated professions to stir interest in sciencerelated careers.
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A Closer Look
Rainforest Layers
Tropical rainforests are the most diverse land habitats on Earth. They are warm all year round and lots of rain means lots of water for living things. There is another reason tropical rainforests are so diverse – layer 53 s. Tropical rainforests have four main layers – the forest floor, understory, canopy and emergent layer. Each layer forms a habit at for different types of plants and animals. You can think of a tropical rainforest as four habitats in one!
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A Closer Look Invokes enthusiasm in science by presenting interesting topics beyond the syllabus.
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Amazing Fact! Interesting facts to build interest and enthusiasm.
Birds reproduce by laying eggs. Parents often care for their young when they hatch from the eggs.
mals with a body thers. They have two wings. Many birds use fly.
Did You Know?
ave beaks of all and sizes. The of the beak helps the get the food it needs. Did You Know? All birds have feathers and wings, but not all can fly. Flightless birds include penguins, emus, ostriches and cassowaries.
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Try This!
Activity 2.3
Optional hands-on activities to be conducted in groups or at home.
What are the characteristics of birds?
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Science Words
volcano erupt magma lava earthquake tsunami
flood landslide thunderstorm wildfire hurricane
4. What process is show n in the pictu
tornado weathering erosion deposition land reclamation
Review
1.
Extra information to build students’ knowledge base of the current topic.
Which best describes the process when soil and rocks fall from mountains and hills. (a) Tsunami (b) Wildfire (c) Landslide
2. Which best describes the process when hot molten rock flows onto the Earth ’s surface? (a) Earthquake (b) Volcanic eruption (c) Thunderstorm
re?
(a) Erosion (b) Weathering (c) Deposition
5. Describe the differ ence between erosion and weat
6. Use the words in the box to erosion
hering.
label the picture.
deposition
Discussion
8. List three processe s that change the shap e of the land rapidly.
Emergent Layer 108
Links students to the Let’s Do Science Activity Book at the appropriate juncture.
(b)
(a)
7. Describe the differ ence between a lands lide and weathering.
3. What can cause a tsunami? (a) Earthquakes and volcanic eruptions (b) Landslides (c) Hurricanes and torna does
AB Activity
9. List three process that change the shap e of the land slowly. 10. Describe two ways people can slow or preve nt changes to the shape of the land. 109
Canopy
Topic-related questions and situations for class discussion to build a deeper understanding of topics.
Understory
Review Forest Floor
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Topical questions at the end of each chapter for formative assessment.
Science Words Lists the essential science vocabulary covered in each chapter.
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Contents Unit 1 – Your Healthy Body Your Body Systems Staying Healthy When You Get Sick Review
2 4 10 18 22
Regal Education Inc Unit 2 – Plants and Animals 24 Classifying Animals The Needs of Plants Plant Parts How Animals Help Plants Review
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26 38 40 44 50
Unit 3 – Habitats Habitats and Diversity Land Habitats Water Habitats Review
54 56 58 70 78
Regal Education Inc 82 Unit 4 – Earth Processes Rapid Changes Slow Changes Human Changes Review
84 94 102 108
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Science Skills Scientists use special skills to learn about the world around them. Let’s look at how you can use these skills so you can be a scientist too.
Observe You observe when you gather information about something using your senses. You can observe how something looks, feels, sounds, smells or tastes.
Regal Education Inc What senses are the children using to observe?
You can use different tools to observe things closely. You can use a hand lens, binoculars or a telescope.
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Compare You compare things when you observe and tell how things are similar or different.
Regal Education Inc How are the hen and chick similar? How are they different?
Classify When you compare two or more things, you can classify them into groups based on ways they are similar.
Leaves in the Garden
How have the leaves been classified into groups?
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Measure You measure when you find the size or amount of something.
You can use tools to help you measure things. You can use a ruler to compare and measure length. You can use a balance to compare and measure mass.
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Make a Model You can make a model to test or see how something works. You can make a model by drawing a picture. You can also make a model by using the things around you to make a smaller version of something to show how it works.
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Infer You infer when you make a guess about something based on what you know or what you observe.
What can you infer about the cause of the holes in the leaf?
What can you infer from observing the tracks in the sand?
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Communicate You communicate when you tell or show other people what you find out.
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You can communicate by making charts, drawing pictures or writing about what you find out.
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Science Investigations Ask Questions Before a science investigation, ask questions about what you would like to find out.
Make a Prediction A prediction is a guess about what you will observe before you make the observation. What are some things you would like to find out about in science?
Regal Education Inc Will a plant grow better in sunshine or darkness?
What do plants need to live and grow?
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A plant will grow better in sunlight.
Plan and Carry Out an Investigation Make a plan with steps that others can follow. List all the materials you will need.
Procedure
Materials
1. Measure the heights of the plants. 2. Put one plant near a window. Put the other plant in a dark cupboard. 3. Water and observe the plants every day for one week.
two plants
ruler
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Observe and Record Data Record the things you observe. You can write or draw the things you observe. You can use charts and tables.
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Analyze and Interpret Data You analyze when you look closely at recorded data. You interpret when you understand and explain what the data means.
Make a Conclusion and Communicate
Regal Education Inc Make a conclusion and communicate it to others.
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Science Safety Follow these safety rules when carrying out investigations.
Wear safety gear.
Follow your teacher’s instructions.
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Keep your workspace clean.
Be careful with sharp objects.
Wash your hands after every activity.
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Your Healthy Body
In this chapter you will ... • learn about the different parts inside your body. • describe how different parts inside your body help you in different ways. • list some ways you can keep your body fit and healthy.
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Can you name some different parts inside your body? What does each part do?
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What things can you do to stay healthy?
Regal Education Inc Go Online! Access interactive content relating to this topic on the NGScience website. ngscience.com
What foods do you eat to stay healthy? 3
Go Online! Discover more about the things inside your body on the NGScience website. QuickCode: G6Q9
Your Body Systems
Your body is made up of different parts. The different parts help your body in different ways. Your legs and feet help you to walk and run. Your nose helps you to smell. Your ears help you to hear sounds around you. There are different parts inside your body too. These parts, such as your heart, lungs and bones, all work together to help your body work in different ways.
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Activity 1.1
Your Heart and Blood Vessels Your heart pumps blood throughout your body. Your blood travels to and from your heart through tubes called blood vessels. Your blood vessels branch out to all parts of your body.
Try This! Gently place two fingers on the left side of your neck. Use a stopwatch to time how many times your heart beats in 20 seconds. Multiply the number of heart beats by three to get your pulse rate.
Regal Education Inc blood vessels
heart
There are two types of blood vessels – arteries and veins. Blood travels away from your heart in arteries. It travels back to your heart in veins. AB
Activity 1.2 5
Try This! Use a stopwatch to find out how many times you breathe in and out in one minute. Calculate how many times you breathe in and out in one hour. How many times do you breathe in and out in one day?
nose mouth
Your Nose, Mouth and Lungs When you breathe in, your mouth and nose take in air. The air moves down your windpipe and into your lungs. Your body needs a special part of air called oxygen. Your lungs take in oxygen from the air and pass it to your blood. Your body makes a gas called carbon dioxide. The carbon dioxide leaves your body when you breathe out.
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Activity 1.3
windpipe
lungs
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Your Mouth, Stomach and Intestines In your mouth, your teeth and tongue work to break down the food you eat into small pieces. When you swallow, the food moves down your esophagus and into your stomach. In your stomach, the food breaks down further. The broken down food moves to your intestines and into the bloodstream. Your body uses the broken down food for energy, growth and repair.
Amazing Fact! If you unraveled your intestines, your large intestine would be about 5 feet long. Your small intestine would be more than 20 feet long!
mouth
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stomach large intestine small intestine AB
Activity 1.4 7
Did You Know? Your bones help to protect important parts inside your body. Your ribs protect your heart and your skull protects your brain.
Your Skeleton Use your right hand to gently squeeze your left wrist. What do you feel?
skull arm bones
rib cage
The hard parts you felt when you squeezed your wrist are bones.
Regal Education Inc spine
hip bone
leg bones
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Your bones help to support your body and give your body its shape. All the bones in your body make up your skeleton. AB
Activity 1.5
Your Muscles Your muscles cover your bones. Muscles pull on your bones to help you to move about.
Try This! Lightly squeeze your left arm just above your elbow. Flex your left arm and describe what you feel.
The more you move around and exercise, the stronger your muscles will become.
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What are some things you can do to strengthen your muscles? AB
Activity 1.6 Go Online! Discover more about your body’s amazing systems on the NGScience website. QuickCode: W6X5
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Staying Healthy Your body can do many different things. To make sure your body is working properly, you need to look after your body by staying healthy. What can you do to keep your body healthy? When you keep your body healthy, it can keep doing all the things you do in a day. If you don’t stay healthy, your body may not work as it normally does. You may get sick more often.
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Healthy Eating Eating healthy is important. Eating healthy food gives your body the energy it needs to function. Eating healthy food can also stop you from getting sick. If you do get sick, eating healthy food will help you to get well sooner.
Try This! Keep a healthy food diary. Give yourself a daily diet score. A high score will have lots of fresh vegetables and fruits! Compare your score with your friends.
Here are some tips on healthy eating: • Start the day with a healthy breakfast. • Eat a good balance of all kinds of food. • Eat lots of fresh vegetables and fruits. • Drink lots of water.
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Activities 1.7 – 1.8
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A Closer Look
Healthy Food Pyramid Different foods and drinks help your body in different ways. When you eat a balanced diet, you eat a variety of healthy food. This helps your body to get all the things it needs to give you energy and help to keep you strong and healthy. Some foods, such as cereals, bread, pasta and potatoes, give you energy.
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Food like meat, chicken, fish and milk help to keep your growing muscles and bones strong.
Vegetables and fruits provide your body with the vitamins and nutrients it needs to keep you healthy as you grow.
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A healthy eating pyramid is a diagram that shows you how much of different foods you should include in your balanced diet. You should eat more foods from the bottom part of the pyramid and less foods from the top of the pyramid. Healthy fats Lean meat, fish, eggs, nuts, milk, yogurt and cheese
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Fruit, vegetables and legumes
Drinking lots of water and being active every day are also important when following a balanced diet. 13
Keep Fit and Active Doing lots of exercise keeps your body strong and fit. Doing lots of exercise will help you sleep better too. To get daily exercise, you could ride a bike, play a sport, walk and run, or just play with your friends. Make a list of some things you can do to keep fit and active.
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The Great Outdoors Regular exercise is a fun way to keep fit and active. It’s even more fun when you exercise in nature! In nature, you’ll get plenty of fresh air and sunshine. You can play your favorite sports, go for a nature hike or go camping with family and friends.
Try This! Make a ‘nature bracelet’ by wrapping a piece of sticky tape around your wrist. Go on a nature walk and collect small things to stick on your bracelet!
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Good Hygiene Keeping your body clean is an important part of staying healthy. The best way to stay clean is to take a bath or shower two times a day – once in the morning and again before you sleep. When you bathe or shower, use soap to wash all parts of your body. Here are some other ways to maintain good hygiene:
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• Brush your teeth twice a day. • Wear clean clothes. • Use shampoo to wash your hair. • Wash your hands after playing outside and before you eat. What are some other ways you can keep your body clean?
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Getting Enough Sleep It is important to get enough sleep. Each night, try to get about 10 to 12 hours of sleep. When you are asleep, your body gets a chance to take a rest and get ready for the next day. Just like eating healthy food and staying clean, sleep helps you to stay fit and healthy. If you don’t get enough sleep, you may not have much energy the next day. You may feel grumpy too.
Try This! Keep a sleep diary by recording the number of hours you sleep each night for one week. Write or draw how you feel each morning.
Did You Know? Scientists believe that dreaming helps you to store memories from the things you’ve learned during the day. People usually have about four or five dreams a night, but usually forget about them by the time they wake up.
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AB Activities 1.9 – 1.10 17
When You Get Sick
Everybody gets sick from time to time. When you are sick, you might have a fever, headache or a sore throat. You might cough and sneeze or feel sleepy. If you think you might be sick, tell a parent right away. Your parents might take you to see a doctor. A doctor can find out why you are sick and help you to get better.
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Go Online! Find out more about colds and the flu on the NGScience website. QuickCode: J4J5
Did You Know?
Colds and the Flu A common way that people get sick is by catching a cold or the flu. You can get a cold or the flu when small germs, called viruses, get inside your body.
When you get the flu, you are contagious. This means you can cause other people to get sick too. That’s why it’s really important to stay home if you think you may have the flu.
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When you have a cold or the flu, you may have a runny nose and a sore throat. You may cough and sneeze too. If you think you may have a cold or the flu, it is important to see a doctor and get lots of rest.
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A Closer Look
What Are Germs? Germs are very tiny things that can cause you to get sick if they get inside your body. Germs are too small to see, but there are some things you can do to keep them out of your body. Germs can get on your hands when you touch objects or other people. Once germs are on your hands, they can get inside your body when you touch your mouth, nose or eyes.
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Germs can also spread from person to person through the air when someone coughs or sneezes without covering their mouth and nose. Here are some things you can do to stop the spread of germs: • Wash your hands with soap and water after playing outside, going to the bathroom and before you eat. • Cover your nose and mouth when you sneeze or cough.
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• Stay at home and away from other people if you are sick. • Wear a face mask if you are sick. AB
Activity 1.11
Did You Know? When you’re sick, a face mask is very useful at stopping the germs in your body from getting into the air. This can stop others from getting sick too.
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Science Words
heart blood vessels artery vein windpipe lungs
oxygen carbon dioxide esophagus stomach intestines bones
skeleton muscles cold flu germs
Review
1.
True or false. (a) Your heart pumps blood around your body. (b) All of your muscles make up your skeleton. (c) Your lungs help you to take in oxygen from the air.
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2. List three body parts that help to break down food. 3. How do your bones and skeleton help your body?
4. What is the difference between arteries and veins? 5. How do your muscles help your body? 6. 22
Which describes a balanced diet? (a) Eating mostly bread and pasta. (b) Eating a variety of different healthy foods. (c) Eating junk food and vegetables often.
7. Write a sentence to tell how each child is keeping healthy. (a) (b)
(c) (d)
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8. List three things you can do to stop the spread of germs. 23
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Plants and Animals
What does a plant need to live and grow? How does it get the things it needs?
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In this chapter you will ... • classify animals into groups based on observable characteristics. • list and describe plant needs, parts and functions. • plan and conduct an investigation to determine if plants need sunlight and water to grow. • describe the role of animals in the processes of pollination and seed dispersal.
Regal Education Inc Go Online! Access interactive content relating to this topic on the NGScience website. ngscience.com
How do animals help plants reproduce? 25
Classifying Animals Go Online! Learn about the different ways we can classify animals on the NGScience website. QuickCode: Z7N1
There are many different kinds of animals. Different animals have different characteristics. We can observe the characteristics of animals and classify them into groups based on how they are similar.
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We can classify animals by looking at their body parts and body coverings. We can also look at how they move, where they live or how they reproduce. Reproduce means to make new young.
Regal Education Inc How could you classify these animals into groups? AB
Activity 2.1
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Mammals Mammals are animals that have a body covered in hair or fur. Many mammals live on land. Some mammals live in water. All mammals have lungs to get the air they need.
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Many land mammals use legs and feet to move about. Some, such as bats, have wings and can fly.
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Amazing Fact! Platypuses are fascinating animals that are a little different from other mammals. They have a duck-like bill, a beaverlike tail and reproduce by laying eggs!
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Most mammals reproduce by giving birth to live young. They often care for the young when they are born. AB Activity 2.2
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Birds Birds are animals with a body covered in feathers. They have two legs and two wings. Many birds use their wings to fly. Birds have beaks of all shapes and sizes. The shape of the beak helps the bird to get the food it needs.
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Birds reproduce by laying eggs. Parents often care for their young when they hatch from the eggs.
Did You Know? All birds have feathers and wings, but not all can fly. Flightless birds include penguins, emus, ostriches and cassowaries.
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Activity 2.3
What are the characteristics of birds?
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Reptiles and Amphibians Reptiles are animals with a body covering of scales or hard plates.
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Most reptiles live on land. Some, such as alligators and turtles, live in water. Reptiles reproduce by laying eggs. They breathe air using lungs.
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Amphibians are animals that live both on land and in water. They often have smooth, moist skin. Most amphibians reproduce by laying eggs that hatch in water. The young have gills. As they grow, the gills change into lungs. As adults, the young move from water onto land.
Regal Education Inc AB Activity 2.4
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Fish Fish are animals that live in water. Most fish have a body covered in scales. They also have fins to help them swim.
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Fish reproduce by laying eggs. They have gills to help them breathe.
Think Deeply
Regal Education Inc Compare a fish with a reptile that lives in water. In what ways are they similar? In what ways are they different?
AB
All fish live in water, but not all live in the ocean. Where are some other places you can find fish?
Activity 2.5
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Insects Amazing Fact! Insects are the most diverse group of animals on Earth. More than one million different types have been named by scientists!
If you observe insects closely, you will notice they all have six legs and three body parts. Insects reproduce by laying eggs.
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Insects come in all shapes and sizes. Some use their legs to move. Some insects also have wings and can fly.
Regal Education Inc Compare an ant and a spider. How can you tell which animal is an insect?
AB
Activity 2.6
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Unlike animals, plants do not eat food. How do plants get the food they need to live and grow?
The Needs of Plants A plant needs certain things from its surroundings to help it to live and grow. A plant needs sunlight, air, water and nutrients. What will happen to a plant if it does not get the things it needs?
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A plant takes in air, water and nutrients from its surroundings. It uses the energy from sunlight to change the air, water and nutrients into food. AB
Activity 2.7
Think Deeply In the ocean, almost no plants can be found deeper than 200 meters. Why is this so?
Regal Education Inc How do the parts of a plant help it to get the things it needs to make food?
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Plant Parts
Roots, Stems and Leaves Plants have different parts. They have roots, a stem and leaves. Many plants also have flowers and fruits.
Regal Education Inc Each part helps the plant to live, grow and reproduce.
Point and name the plant parts. Tell how each part helps the plant.
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Roots help the plant to take in water and nutrients from the soil. They also hold the plant firmly in the ground. The stem holds up the plant. It carries the water and nutrients to the leaves and other parts of the plant. The stem also carries food from the leaves to other parts of the plant. Leaves take in air and catch the sunlight the plant needs to make food.
Regal Education Inc How is the shape of the roots, stem and leaves suited to their functions? AB
Activity 2.8
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Flowers and Fruits Amazing Fact! A Rafflesia plant produces flowers that can grow up to a meter wide. The flowers smell like a dead animal, which attracts flies and other insects.
Many plants have flowers. The flower is the plant part that makes the seeds from which new plants will grow. Flowers contain a sticky powder called pollen. To make seeds, pollen needs to move from one part of a flower to another. This process is called pollination.
Regal Education Inc What are some ways pollen can move from one flower to another? AB
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Activity 2.9
When a flower begins to make seeds, it changes into a fruit. Fruits help to protect the seeds. Some fruits, such as apples and berries, are fleshy. Others, such as nuts, are dry and hard.
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Along with protecting the seeds, fruits can also help move the seeds to new places.
What are some ways fruits can move seeds to new places?
Try This! In small groups, make a list of some fruits you know. Classify the fruits as fleshy or dry.
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How Animals Help Plants Pollination Go Online! Observe the different ways animals help pollinate plants on the NGScience website. QuickCode: H7Z9
To make seeds, the pollen usually needs to move from one flower to another. Often this is done by animals. An animal that moves pollen from flower to flower is called a pollinator. Many flowers are brightly colored or contain a sweet liquid called nectar. This helps to attract pollinators such as bees, butterflies, beetles and birds.
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Regal Education Inc When a pollinator lands or feeds on a flower, pollen sticks to the animal. Some of the pollen grains fall off when the pollinator moves to a new flower. AB Activity 2.10
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A Closer Look
Hummingbirds Most plants with flowers are pollinated with the help of insects, such as bees and beetles. Some plants have flowers that are long and thin. The pollen may sit deep inside the flower and cannot be reached by insects. These flowers often attract hummingbirds.
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Hummingbirds feed on a sweet liquid produced by the flower, called nectar. They use their long, thin bills to reach deep inside the flower. When feeding on the nectar, pollen stick to their bills.
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When a hummingbird moves to a new flower, some of the pollen fall off and pollination occurs. Hummingbirds feed up to 10 times per hour. In one day, they may eat as much as half their body weight in sugar!
Amazing Fact! Hummingbirds are the only birds that can fly backwards. Some hummingbirds have even been spotted flying upside down.
Regal Education Inc Go Online!
Find out more about these fascinating birds on the NGScience website. QuickCode: J7J1
Engineer It! Design and build a flower that a hummingbird may feed on. Develop a simple model that mimics the function of the hummingbird in pollinating the flower.
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Seed Dispersal
Go Online!
Many plants have ways to move seeds away from the parent plant. This is called seed dispersal. Seed dispersal helps plants grow in new places.
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Observe the different ways plants disperse their seeds on the NGScience website. QuickCode: Y9N9
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Different plants can disperse their seeds in different ways. Some seeds are light or have shapes that help them float in the air. These seeds can be dispersed by wind. Other seeds float. They can be dispersed by water.
Many plants use animals to help disperse their seeds. Some plants have seeds with barbs. They stick to the fur of animals. The seeds drop off when the animals move from place to place. Animals can disperse seeds when they eat a fruit and drop it in a new place. Some animals eat the fruits and seeds. The seeds can pass through the animal and are spread in the animal’s waste.
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Activity 2.11
Engineer It! Develop a model that mimics the function of an animal dispersing seeds. What animal did you mimic? How were the seeds dispersed?
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Science Words
mammals birds reptiles amphibians fish
insects roots stem leaves
flowers fruits pollination seed dispersal
Review
1.
True or false. (a) All mammals live on land. (b) All birds have feathers. (c) All birds can fly.
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2. Which animal group has a body covered in hair or fur? (a) Mammals (b) Fish (c) Reptiles (d) Birds 3. Which animal group lays eggs and has lungs? (a) Fish (b) Reptiles (c) Mammals (d) Insects
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4. Draw and complete a Venn diagram to compare reptiles and mammals. Reptiles
Mammals
5. Draw and complete a Venn diagram to compare birds and insects.
Regal Education Inc Birds
Insects
6. List the needs of plants. 7. What is pollination? 8. List two animals that help pollinate flowers. 9. Describe two ways animals help plants disperse seeds. 51
In the Field
If you love plants of all shapes and sizes, you might want to be a horticulturist. A horticulturist is a scientist that specializes in growing plants for people to use. Horticulturists use their knowledge of plants to help farmers improve the fruits, flowers and vegetables they grow.
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Horticulturists can also use their knowledge of plants and soil to help manage and protect natural areas like parklands or nature reserves.
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Habitats
Go Online! Access interactive content relating to this topic on the NGScience website. ngscience.com
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What are some places where living things live?
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What is diversity? How is the diversity of life different in different habitats?
In this chapter you will ... • describe different plant and animal habitats.
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• compare and describe the diversity of different habitats. • collect, record, and organize data on different types of plants and animals in different habitats.
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Habitats and Diversity There are many different kinds of habitats on Earth. A habitat is the place where a living thing lives. It provides the living thing with all the things it needs to survive. Some habitats, such as forests, deserts and grasslands, are on land. Others, such as lakes, rivers and the ocean, are in water.
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Habitats are different in many ways. Some are warm and get lots of rain. Others are very hot and dry.
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Habitats can be big or small. A home garden is a small habitat. The Sahara is a desert habitat that is almost as big as the United States.
Diversity is the number of different plants and animals that live in a habitat. Some habitats support a great diversity of living things. Others can only provide the things for a few kinds of plants and animals. They have low diversity. AB
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Land Habitats A Home Garden
A garden is a habitat usually made by people. Gardens are often small, but they can support a diversity of living things. People often plant many different kinds of plants in gardens. The great variety of plants also attracts many kinds of animals.
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Many kinds of insects, such as bees, beetles and butterflies, live in a home garden. There may also be snails and larger animals like rabbits and mice.
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Some animals also live underground. AB Activity 3.2
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Temperate Forests
Go Online!
A temperate forest is a habitat that gets enough rain and sunlight for many trees to grow. Grass, shrubs and ferns may also cover the forest floor.
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Observe and compare the diversity of life in forests on the NGScience website. QuickCode: B5F1
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During fall, the leaves on many trees change color and fall to the ground. The trees grow new leaves in spring.
The many plants and trees in a temperate forest provide lots of food and places for animals to live. There may be squirrels, raccoons, bears and deer. The hollows in trees provide shelter for many types of birds.
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Tropical Rainforests A tropical rainforest is a habitat that gets lots of rain and sunlight. It is also warm all year round.
Amazing Fact!
Rainforests are the most diverse land habitat on Earth. Many kinds of plants and animals live in all parts of a rainforest. There are tall trees of all shapes and sizes. There are shrubs, ferns and mosses. Mosses and other small plants grow on rocks, tree trunks and logs.
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Tropical rainforests cover less than three percent of Earth’s surface, but are home to more than half of Earth’s land animals.
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The great diversity of plants provide food and shelter for many animals. There are many kinds of birds, snakes, frogs and insects. There are many kinds of large and small mammals too.
Regal Education Inc Why are rainforests such diverse habitats?
AB Activity 3.4
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Deserts A desert is a habitat that is dry and gets very little rainfall. Some deserts are very hot. Others can be hot during the day and cold during the night.
Regal Education Inc Go Online! Learn more about the diversity of life in deserts on the NGScience website. QuickCode: L5T7
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With not much water, few plants and animals can live in deserts. Desert plants can survive for a long time without water.
Some plants have long roots to take in water from deep underground. Others have roots that spread out over a large area. Some plants store water in their stems.
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Reptiles, such as snakes, lizards and tortoises, can be found in deserts. Desert animals can also survive with little water. Many desert animals get the water they need by eating plants. Why do some desert plants have sharp, spiky leaves? AB Activity 3.5
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Tundra Go Online! What kinds of animals can survive in a harsh tundra habitat? Find out on the NGScience website. QuickCode: M3H8
In a tundra habitat, it is cold all year round. There is very little rain and it is often windy. Few trees grow in tundras. Most plants are grasses or small shrubs.
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For most of the year, the ground is covered in snow or ice. During the warmer months in spring and summer, many shrubs produce colorful wildflowers.
Not many animals can survive in the cold and dry tundra habitat. During winter, many tundra animals move underground to stay warm or move to warmer places.
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Some tundra animals include polar bears, reindeer, foxes and hares. AB Activity 3.6
Amazing Fact!
The word tundra comes from the Finnish word tunturi, which means ‘treeless plain’.
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Savanna Go Online! Learn more about the diversity of life in an African savanna on the NGScience website. QuickCode: U1H6
A savanna, also called a tropical grassland, is a habitat that is hot and dry for most of the year. There are large areas of grasses and small shrubs. There are scattered trees.
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Many animals that live in a savanna get the food and water they need by eating plants. When it rains, many animals are attracted to large waterholes that form in the ground. Savanna animals include elephants, giraffes, zebras, wildebeests and lions. There are also a variety of birds.
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Water Habitats Ponds and Lakes
Ponds and lakes are closed freshwater habitats. Many plants live in the land surrounding the water. Plants live on and under the water too. Many plants surrounding ponds have flowers that attract insects and other small animals.
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Many animals live in pond and lake habitats. Common animals include turtles, frogs and birds. There may also be reptiles such as lizards and snakes.
Try This!
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A variety of animals live near, on or under the water too. AB
Activity 3.8
As a class, plan a field trip to a pond or lake in your area. Draw or take photographs of the plants and animals you spot.
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Rivers and Streams Go Online! Observe and compare the diversity of life in freshwater habitats on the NGScience website. QuickCode: P8M8
Like ponds and lakes, rivers and streams are also freshwater habitats. The water in a river moves from one place to another.
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With lots of water, many plants and animals live in and around rivers.
Trees, large shrubs and grasses live around rivers and streams. Their roots take in water from the wet soil.
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You will find a diversity of animals living in and around rivers and streams, including fish, reptiles, mammals and birds. AB Activity 3.9
Amazing Fact! The Amazon river dolphin is a special species of dolphin that live in the freshwater rivers and streams of the Amazon river.
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Wetlands
A wetland is a habitat that is flooded with water for all or most of the year. Some wetlands have fresh water and some have salt water.
Regal Education Inc As the amount of water in a wetland changes, the plants and animals that live there can change too.
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During the wet season, a wetland has many plants. There are grasses, shrubs and small trees.
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Some plants may die if the wetland dries up. They grow back when the water returns. A great variety of animals live in wetlands. There are many types of insects, fish, amphibians, reptiles and mammals.
What happens to the animals in a wetland when it dries up? AB Activity 3.10
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The Ocean In what ways are ocean habitats different from lakes and rivers? The ocean is a very large body of salt water. Oceans are the largest habitat on Earth – they cover most of the Earth’s surface. Go Online!
Ocean habitats can be different in many ways. Some are shallow and have warm water. Other ocean habitats are deep and cold all year round.
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Different animals live in different parts of the ocean. Find out more on the NGScience website. QuickCode: Y9B2
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Oceans are the habitat of a great diversity of animals. Fish, like most ocean animals, have gills to get the air they need from water.
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Some ocean animals, like dolphins, whales and turtles, have lungs. They come to the surface to breathe in air.
AB
Activity 3.11
Why are ocean habitats home to such a variety of animals? 77
Science Words
habitat diversity temperate forest tropical rainforest desert tundra
savanna pond lake wetland ocean
Review
1. Which best describes a habitat? (a) A place that gets lots of rain. (b) The place where a living thing lives and gets all the things it needs to survive. (c) The number of different animals living in an area.
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2. Which best describes the diversity of a habitat? (a) The variety of plants in an area. (b) The place where a living thing lives and gets all the things it needs to survive. (c) The number of different living things living in an area. 3. Why is diversity high in a tropical rainforest habitat? 4. Why is diversity low in a desert habitat?
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5. Copy and complete the table. Habitat
Description
Diversity
Tropical Rainforest Temperate Forest Desert Tundra
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A Closer Look
Rainforest Layers Tropical rainforests are the most diverse land habitats on Earth. They are warm all year round and lots of rain means lots of water for living things. There is another reason tropical rainforests are so diverse – layers. Tropical rainforests have four main layers – the forest floor, understory, canopy and emergent layer. Each layer forms a habitat for different types of plants and animals. You can think of a tropical rainforest as four habitats in one!
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Emergent Layer
Canopy
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Forest Floor
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Earth Processes What processes change the surface of the Earth? Go Online!
Access interactive content relating to this topic on the NGScience website. ngscience.com
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In this chapter you will ... • list and describe events that can change the surface of the Earth. • classify events that change the surface of the Earth as those occurring slowly or those occurring quickly. • describe and compare solutions designed to slow or prevent wind or water from changing the shape of the land.
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Rapid Changes Go Online! Watch how volcanoes, earthquakes and extreme weather can rapidly change the surface of the Earth on the NGScience website. QuickCode: J1L2
What events or processes change the surface of the Earth quickly? The surface of the Earth is always changing. Some processes change the surface of the Earth quickly. Such processes include volcanic eruptions, earthquakes and extreme weather events like floods, tsunamis and hurricanes.
Regal Education Inc Volcanoes
Amazing Fact! One of the most destructive volcanic eruptions in history was the eruption of Krakatoa in Indonesia in 1883. The explosions were so violent that they could be heard from almost 5,000 kilometers away!
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What is a volcano? How do volcanoes change the surface of the Earth?
A volcano is an opening in the Earth’s surface that is caused when hot molten rock, called magma, pushes up from inside the Earth. A volcano erupts when the magma bursts through its opening and flows onto the Earth’s surface as lava.
When the lava cools, it changes to solid rock. The formation of the solid rocks changes the shape of the surface of the Earth.
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Earthquakes What causes an earthquake? How do earthquakes change the surface of the Earth? Go Online! Discover what causes earthquakes on the NGScience website. QuickCode: J1Y6
The surface of the Earth is made up of different layers. An earthquake is the shaking of the ground that occurs when the layers rub against each other. Earthquakes occur all the time. Most are too small to be felt. Others can be very large. They can cause rapid changes to the surface of the Earth.
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Large earthquakes can change the surface of the Earth quickly. They can cause cracks in the ground and damage to roads, bridges and buildings.
Regal Education Inc Try This! Draw Drawaapicture pictureof ofthe the Earth’s surface. Show Earth’s surface. Show how howthe thesurface surfaceof ofthe the Earth will change after Earth will change after an anearthquake. earthquake.
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Go Online! Learn about the 2004 Indian Ocean earthquake and tsunami on the NGScience website. QuickCode: A4F2
Tsunamis A tsunami is a very large and powerful wave that forms in the ocean and moves onto land. It can change the surface of the Earth quickly. Tsunamis are caused by disturbances on the ocean floor, such as an earthquake or a volcanic explosion. The disturbance makes waves that move towards land.
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Large tsunamis can cause widespread damage when they reach the shore. They can destroy homes, buildings and roads.
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Floods
A flood is an overflow of water onto an area that is usually dry land. Floods can occur when an area gets much more rain than usual. Heavy rains can also cause rivers and lakes to overflow. Floods can change the shape of the land. They can wash away plants and trees and cause damage to roads and buildings.
Regal Education Inc What are some causes of floods? How can a flood change the surface of the Earth?
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Landslides Landslides occur when soil and rocks fall from mountains or hills. Landslides can be caused by earthquakes, volcanic activity, heavy rain and floods. The roots from plants and trees often hold soil in place. People can cause landslides when they remove the plants and trees. Landslides cause quick changes to the surface of the Earth. They can also cause damage to roads, bridges and houses.
Regal Education Inc Engineer It! Heavy rain can cause landslides on mountains and hillsides. Design two solutions to help prevent the landslides.
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Thunderstorms and Wildfires A thunderstorm, or electrical storm, is a storm with heavy rain and strong winds. Lightning can strike the ground, trees and buildings.
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Thunderstorms can damage property and cause flooding. Sometimes the lightning can start wildfires. A wildfire is a large and uncontrolled fire in nature. Wildfires can destroy large areas of plants and trees and also destroy houses and property.
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Hurricanes and Tornadoes Amazing Fact! The winds of a tornado can reach speeds so fast that they throw cars and trucks hundreds of meters!
A hurricane is a very large storm that starts in the ocean and moves onto land. During a hurricane, large ocean waves may wash onto land. There are very strong winds, heavy rain and flooding.
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A tornado is a rotating column of air that occurs on land, often during a thunderstorm. There are very strong winds. Hurricanes and tornadoes can cause the surface of the Earth to change quickly. They can uproot trees and destroy property. How is a hurricane similar to a tornado? How is it different?
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Slow Changes What processes change the surface of the Earth slowly over time? The surface of the Earth is always changing. Some changes occur very slowly. We cannot see these changes from day to day. The changes occur over many years.
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Mountains Mountains are tall landforms that rise above the land around them. Many large mountains are formed when layers of the Earth push together. This makes the land where the layers meet rise upwards. Over millions of years, the rising of the land forms a mountain.
Try This! Take two sheets of paper and lie them on a table. Push the sheets of paper together. What do you observe? How is this similar to how mountains form?
Amazing Fact!
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Mount Everest is the highest point on Earth. It has a height of 8,849 m (29,032 ft). The mountain has been slowly forming over the past 60 million years!
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A Closer Look
How Mountains Form The Earth is made up of different layers. The outer layer is made up of large, moving pieces called tectonic plates. The tectonic plates are always moving. Mountains can form where the tectonic plates meet and smash together. The collision forces the land upward forming a mountain.
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Some mountains are formed from volcanic eruptions.
Mountains can also be caused by volcanic eruptions. During a volcanic eruption, magma erupts and flows onto the Earth’s surface as lava. Mountains can form when the lava cools into solid rock.
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Weathering Weathering is one way the surface of the Earth changes slowly. Weathering is the breaking up of rock over time. Weathering can be caused when water fills the gaps in rocks. When the water freezes into ice, it expands. This breaks the rock into pieces.
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Plants can also cause weathering. Plant roots can grow into the cracks of rocks and break the rocks into smaller pieces. People and animals also cause weathering by stepping on rocks and soil.
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How does weathering change the surface of the Earth over time? 99
Erosion and Deposition Erosion is the removal of broken down rock, soil and sand from an area. Erosion is often caused by moving water in streams, rivers and the ocean. It is also caused by wind. Some events, such as floods and hurricanes, can cause erosion to happen quickly. Erosion also occurs over many years. It changes the surface of the Earth by forming rivers and canyons and shaping the coastline.
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How does erosion change the surface of the Earth over time? 100
Broken down rocks, soil and sand that are removed by erosion are moved to new places. This process is called deposition. Just as erosion changes the shape of the land by removing parts of the Earth, deposition changes the land by moving it to a new place. AB
Go Online! Discover more about erosion and how it changes the Earth’s surface on the NGScience website. QuickCode: X9J8
Activity 4.3
Engineer It!
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In the coastal town of Broadbeach, wind and water are changing the shape of the land. Build a model of the town to show how erosion and weathering can change the shape of the land. Design a solution to help prevent the erosion.
Discuss the ways in which weathering, erosion and deposition are different. 1 01
Human Changes Changing Land Think Deeply
People can change the surface of the Earth in many ways. We change the shape of the land when we clear forests for wood, farms or to make way for cities.
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How can clearing land to build a road have a positive effect on the environment? What are the negative effects?
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We change the shape of the land when we build structures such as buildings, roads and bridges.
We change the shape of the land when we dig mines to take resources from under the ground. The changes people make to the Earth can also cause more floods, landslides, erosion and deposition.
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How do human changes increase the occurrence of floods and erosion? 103
Amazing Fact! The tallest dam in the United States is the Oroville dam in California. It has a height of around 235 meters!
Changing Water People change water in many ways. We drain or change the shape of lakes and rivers to use the water for transport, farming or to produce electricity.
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People can also change the shape of the land by creating new land from oceans, seas, riverbeds or lake beds. This process is called land reclamation.
Go Online! Explore the different ways people change water on the NGScience website. QuickCode: Y5P9
Regal Education Inc Discuss the ways human activities change the shape of the land. Do the changes occur quickly or slowly?
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Slowing and Preventing Changes People try to slow or prevent wind, water and human activities from changing the shape of the land. We make trails for hiking to prevent weathering and erosion. We plant trees to hold soil and sand in place.
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People build structures to stop or slow the movement of water and wind. Dikes and levees are barriers built by people to hold back water. This can help to slow and prevent weathering and erosion.
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Windbreaks can slow strong winds from weathering rocks or moving sand and soil. AB
Activity 4.4
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Science Words
volcano erupt magma lava earthquake tsunami
flood landslide thunderstorm wildfire hurricane
tornado weathering erosion deposition land reclamation
Review
1. Which best describes the process when soil and rocks fall from mountains and hills? (a) Tsunami (b) Wildfire (c) Landslide
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2. Which best describes the process when hot molten rock flows onto the Earth’s surface? (a) Earthquake (b) Volcanic eruption (c) Thunderstorm 3. What can cause a tsunami? (a) Earthquakes and volcanic eruptions (b) Landslides (c) Hurricanes and tornadoes
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4. What process is shown in the picture?
(a) Erosion (b) Weathering (c) Deposition 5. Describe the difference between erosion and weathering. 6. Use the words in the box to label the picture. erosion deposition
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(b)
7. Describe the difference between a landslide and weathering. 8. List three processes that change the shape of the land rapidly. 9. List three process that change the shape of the land slowly. 10. Describe two ways people can slow or prevent changes to the shape of the land. 109
In the Field
A scientist who studies rocks and the processes that shape the Earth is called a geologist. Geologists closely observe the Earth’s processes and the way they change the shape of the land. They use what they learn to help protect natural areas. They also help people plan and prepare for rapid changes to the Earth such as volcanic eruptions, earthquakes and hurricanes.
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Geologists often work outside, collecting data about the Earth. They learn how the shape of the land on Earth has changed over time. They observe patterns to predict how the Earth will change in the future.
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© Blue Ring Media Pty Ltd ACN 161 590 496 2013 - 2021. This publication would not have been possible without the tireless effort of our production team. Special thanks to: Matthew Cole, Daniel Cole, Wang Hui Guan Joseph Anderson, Halle Taylor-Pritchard, Sophie Taylor-Pritchard, Tejal Thakur Varasinun Mathanattapat, Kanungnit Pookwanmuang, Saijit Lueangsrisuk Original Illustrations: Natchanuch Nakapat, graphicsRF, Blue Ring Media and Interact Images Royalty-free images: Shutterstock, Adobe Stock