Feelings SEE ALSO ▸▸ Art p.28 Feelings are how we respond to things that happen in ▸▸ Brain p.45 and to us. Feelings affect our brains, bodies, and how ▸▸ Heart p.128 we behave. Being able to tell other people our feelings ▸▸ Language p.144 is important and helps us to feel connected to each other. ▸▸ Philosophy p.189 ▸▸ Taste p.249 Disgusted Happy Sad Disgust is a strong Chemicals are released If something bad feeling of dislike for in the brain when we or disappointing something we see, do things we like. The happens, we feel sad. hear, smell, or taste. Sometimes we cry chemicals make when we are sad. us feel happy! Scared Expressions Angry If we are in danger we We get angry when feel scared. Our heart The different faces we think something is beats faster to help people use for unfair or wrong. Anger makes our heart beat us get away from feelings are called faster and our muscles the situation. expressions. tense up. 99
Film SEE ALSO ▸▸ Art p.28 A film, or movie, is a series of still images that are quickly played one after the other, so that the pictures seem to ▸▸ Storytelling move. Films are used to tell stories or show real events. pp.42–43 They were first invented in the late 1800s. Live action films are recorded on cameras. Animations are usually ▸▸ Machines p.150 drawn by hand or on a computer. ▸▸ Photography p.190 ▸▸ Television p.251 ▸▸ Theater p.253 E.T. the Extra-Terrestrial (1982) The Eagle Huntress (2016) Spy Kids (2001) Film types “Genre” is a French word that means type. Films are grouped into genres when they have similar stories or styles. Common genres include action, science fiction, and documentary. 2,000Around Science fiction Documentary Action Sci-fi films explore themes of Documentaries are a record of real Action films are exciting stories new films are made science and technology, such as life or actual events. They show about imaginary heroes or in India every year. space. “Fiction” means imaginary, the wonders of nature and how heroines. They use their strength and the science is often made up. people live. This was one of the and intelligence to stop people The Wizard of Oz (1939) first film genres. from doing bad things. Animation Silent films Animated films bring drawings or models to life on screen. Drawings are made by hand or Technology has come a on a computer. Stop-motion is a long way since films were type of animation that uses invented. The first films models. The models are were in black and white, photographed, moved, and and had no sound. photographed again. Background music was played live at the cinema, and actors used their faces and body gestures to tell a story. Musicals Charlie Chaplin in These stories are told through A Dog’s Life (1918) music, song, and dance. They became popular in the 1930s, when films were made with sound and color for the first time. My Neighbor Totoro (1988) 100
Fish SEE ALSO ▸▸ Life cycle p.146 Fish are animals that live in water. They are able to breathe underwater, and have fins to help them swim around. ▸▸ Pets pp.152—153 There are more than 3,000 different species of fish in the world. ▸▸ Oceans and seas p.187 ▸▸ Seashore p.220 ▸▸ Vertebrates p.266 The body is covered in Gills are special plates made of thin organs that let fish bone, called scales. breathe the gas oxygen underwater. Lionfish Fins steer the Goldfish fish through Long spines protect lionfish the water. Goldfish are the most from other animals. popular pet fish. Newborn They hunt at night, Deadly fins are used goldfish are shiny brown. feeding on small to knock out other They turn golden when they fish, crabs, sea animals. are a year old. and shrimp. Stinging tail Stingray Seahorse dad Red lionfish has one or two poisonous spikes. These fish are found Most fish don’t look after Morays have a in warm, shallow their eggs. Seahorses are poisonous bite. Blue spots let other waters. Most of their different—the male carries fish know that the time is spent buried the eggs around in a pouch Eel stingray is deadly. in the sand, waiting on its belly, until they hatch. to pounce on other Eels are long fish that look sea animals. like snakes. They have more than 100 bones in their spine, which makes them very bendy. Zebra moray eel Blue spotted stingray 101
Flags SEE ALSO ▸▸ Africa p.12 A flag is a piece of material showing a unique set of colors and symbols. Flags represent a country, city, religion, ▸▸ Color pp.26–27 organization, or sport. The symbols and colors can also represent a message, such as a request for help. Flags ▸▸ Asia p.29 are often flown from flagpoles outside buildings to show who the building belongs to. ▸▸ Governments p.123 National flags ▸▸ North America Each country has its own special flag, p.184 called a national flag. Most of these have colors or stripes with stars or other ▸▸ World p.275 symbols placed on top. Each part says something about the country. China USA Red stands for communism, which is The stars stand for the 50 US the type of government in China. states. The stripes are for the The stars show communism and original 13 states. The flag is Chinese unity. nicknamed “the stars and stripes.” United Kingdom Germany India The upright red cross and The black, red, and The colors stand the diagonal red and white gold are from the for ideas such as crosses show the English, uniforms of German peace and truth. Northern Irish, and Scottish soldiers in the 1800s. The central wheel flags of the United Kingdom. symbol is from the The first national Buddhist religion. Kenya flag was flown in The shield is a sign of Signal flags the Maasai people of 1478Denmark in Kenya. The color white . Flags can be used to send messages. represents peace. Ships use flags to ask for help if they are 102 in trouble, or to tell other ships to keep out of the way. “I need help” “I need “Keep clear a pilot” of me”
Flowers SEE ALSO ▸▸ Fruit and seeds Flowers are a part of a plant. To make new seeds, they swap tiny grains called pollen. Pollen can p.115 be spread by wind or insects. Flowers have brightly ▸▸ Habitats p.126 colored petals to attract insects. ▸▸ Insects p.134 ▸▸ Plants p.194 Flower structure Stigma ▸▸ Shapes p.222 This is sticky to ▸▸ Trees p.261 Flowers have male and female catch any pollen parts. To make a seed, pollen that is carried Anthers passes from the male part of to the flower. These are the male one flower to the female parts of the flower. part of another. They are covered in tiny grains of pollen. Petals Ovary Filament These are This is the female part This stalk brightly colored of the flower where holds up to attract insects new seeds form. the anther. to the flower. The tallest flower Insects is the Titan arum. Insects help to move pollen from the anther of one flower to the stigma of another. The pollen It grows more than travels on their bodies. Once transferred, the pollen fertilizes the ovary to form seeds. 10 ft (3 m) high. Flower shapes Dome Different shapes of flowers attract different insects. Some insects fit down long, narrow flowers, others need big petals to land on. Cone-shaped Regular Rosette Bell-shaped 103
The story of... Ribs with black- eyed peas and Eating collard greens, from the US When we eat, we take in all the things we need to keep us alive and healthy. Eating food gives us the energy that allows us to think, walk, play, and work. It is also something we love to do. Paella from Spain Food around the world People used to only eat things that were grown near them. Now, we can eat food from all over the world. Different countries have their own special recipes to make their favorite foods. Pizza from Italy Kebabs from Turkey Dosa from India 104
Early eating Food allergies Our ancient ancestors Some people are allergic to hunted for meat and fish, certain foods, which means and foraged for fruit, nuts, they become ill when they eat and roots. They started them. These foods can include using fire to cook food shellfish, peanuts, and around 400,000 milk-based foods. years ago. Fire Chow mein 1.3More than Peanuts from China billion people in the world work as farmers. Bento box Farming from Japan People began farming at least 15,000 years ago. Today, almost half of the world’s land is farmed for food. Farmers breed animals for their meat, milk, and eggs. They also grow plants called crops, such as wheat and oats. Combine harvester cutting wheat Insect protein Edible Eating in space mealworms Insects such as mealworms Astronaut space food must and caterpillars are eaten be easy to eat, light in weight, all over the world. They don’t quick to prepare, and not too need a lot of space to grow, so messy. Food is often freeze- they are an environmentally dried and put in pouches. friendly alternative to Water is then added farmed meat. before eating. Astronaut food 105
Food SEE ALSO ▸▸ Digestion p.79 Humans need to eat the right mixture of different food ▸▸ Energy pp.88–89 groups to keep all the parts of the body working properly. ▸▸ Eating Food gives us energy to move, grow, and repair our bodies. Types of food give our bodies the different pp.104–105 goodness we need. ▸▸ Food chains Food groups p.107 ▸▸ Gases p.117 There are five main food ▸▸ Plants p.194 groups that give us the nutrients and vitamins Carbohydrates we need to be healthy. Bread, rice, cereal, and pasta contain carbohydrates, which give our bodies energy. Dairy foods Milk, yogurt, cheese, and butter contain calcium to help teeth, nails, and bones grow. Fruit and Protein vegetables Meat, fish, eggs, Fruit and and beans are vegetables have high in protein, fiber, which helps which is needed break down our food. to grow and They also contain repair our bodies. vitamins and minerals that help our bodies work properly. Drinking Water transports the goodness we get from food into and around our body. It then flushes waste materials out of our bodies. Fat and sugar Energy Sugar and fat give our bodies energy. We can When we eat, our body get fat from food like changes energy in food into cheese and nuts, and the energy we need to move sugars from fruits. and grow. Stored energy is Too much fat and turned into movement sugar is bad for us. energy in our bodies. 106
Food chains SEE ALSO ▸▸ Animal groups A food chain is the passing along of energy from food. Only plants can make their own food. All animals are part p.22 of a food chain, either eating plants or other animals. All animals need energy to grow, survive, and reproduce. ▸▸ Conservation p.72 Energy on the move ▸▸ Eating pp.104—105 Energy moves along a food chain. Each animal ▸▸ Food p.106 in the chain gets energy from what it eats. The arrows show how the food energy is passed along. ▸▸ Habitats p.126 ▸▸ Photosynthesis p.191 Producer Primary consumer Secondary consumer Decomposer Plants produce their own food Animals that eat plants Meat-eating animals that These animals break down by a process using light from are called primary eat plant-eaters are called decaying material, such as the sun. In a food chain, they consumers. They are secondary consumers. They dung, returning the goodness are called the producers. also called herbivores. are also known as carnivores. to the soil for plants to use. Food web Swarms could Plant Plenty of plants means Plenty of plant- eat too many there can be plenty of eaters means Animals don’t just feed plants and plant-eaters. meat-eaters on a single type of plant affect other can survive. or animal, so food chains plant-eaters. become food webs. These can show how energy Antelope is passed around a whole habitat. Carnivores eat a Grasshopper great variety of food to survive. Meerkats eat grasshoppers, scorpions, and other small animals. Meerkat Scorpion Lion Tertiary consumer Martial eagle Dung If food energy has been beetle transferred three times, the animal is called a tertiary consumer. 107
Forces SEE ALSO ▸▸ Friction p.114 A force is a push or a pull. Forces can start things moving, ▸▸ Gravity p.125 speed them up, or slow them down. Some forces work ▸▸ Magnets p.151 through touching. Others, such as gravity, work invisibly ▸▸ Measuring p.159 and can affect objects a long way away. ▸▸ Solar system p.233 ▸▸ Sun p.247 Pushing force A push away Gravity from the hand. A pushing force makes things start to move Gravity pulls objects down and can also speed them up. Your hand applies toward the Earth. It’s the a pushing force when it moves a toy car. force that stops us from floating off into space. Gravity pulls the ball down. Pulling force A pull toward Magnetism the hand. A pulling force also makes Magnetism is a force that things start to move. It moves pulls objects toward a things forward from where magnet, or pushes them the force is coming. away. Opposite magnetic forces attract each other. +— +— The magnets pull together. Friction Balanced forces Friction Engine power Friction is a force that pulls the car pushes the slows down movement. Pushes and pulls can act backward. car forward. in different directions at It is created when two the same time. If they When you sit still surfaces touch. are balanced, the object moves at a steady in a chair, the forces Muscles speed, or is still. If one power the force is bigger, the object on you are perfectly leg forward. gets faster or slower. balanced. Friction drags Gravity pulls the leg backward. the car down. 108
Forests SEE ALSO ▸▸ Animal homes p.23 Forests are places where many trees grow. Forests grow in a wide range of places all over the world. There are ▸▸ Fruit and seeds different types, depending on the temperature and how p.115 much rain they get. Different trees, plants, and animals live in each type of forest. ▸▸ North America p.184 ▸▸ Rain forests p.204 ▸▸ Seasons p.221 ▸▸ Trees p.261 Deciduous forests Silver birch Coniferous forests Black-capped trees have chickadees These forests have four seasons, with warm silvery bark on These forests are found in cold, northern nest in rotting summers and cold winters. Many trees drop their trunk. parts of the world. The trees have needlelike tree stumps. their leaves in autumn and grow them back leaves. Their branches slope so that any snow in spring. These are called deciduous trees. slides off. These are called coniferous trees. Beech trees Oak trees can Spruce trees have Jack pines produce spiky live for hundreds sharp-tipped, have seeds in beechnuts of years. prickly needles. structures called in autumn. pine cones. Grey wolves White-backed grow thick woodpeckers fur in winter. peck holes in trees to find food and make nests. Brown bears are Black bears can one of the world’s climb trees. largest meat-eaters. Ferns grow in Red foxes have bushy Snowshoe hares Moose grow new damp, shady tails to help them grow thick white antlers every year. places. balance and keep warm. fur in winter. Spruce grouses search Fungi live on Wild boars dig Beavers build their the forest floor for damp, rotting wood. with their snout homes from tree trunks. needles to eat. to find food. Dead wood provides food and shelter for Polish forest Lichens grow Canadian forest small animals. This large area of on rocks and These forests are covered in forest is home to many tree trunks. snow for most of the year. The Common shrews eat many animals. Parts of the plants and animals that live here small animals each day. forest are protected, to must be able to survive the cold. keep them as they are. 109
Fossil fuels SEE ALSO ▸▸ Carbon cycle p.49 Fossil fuels are natural materials that formed underground ▸▸ Climate change millions of years ago. We dig them up or pump them out of the ground so that we can burn them to make energy p.60 to power vehicles or to make electricity. There are three ▸▸ Dinosaurs p.80 types of fossil fuel: coal, crude oil, and natural gas. ▸▸ Fossils p.111 ▸▸ Industrial How fossil fuels form Revolution p.133 Fossil fuels are made from dead sea ▸▸ Pollution p.198 creatures and rotten plants. These materials are buried deep under layers Coal of rock and soil that have built up over time. Heat and the weight of the Coal is dug from mines that extend deep ground above change them into underground, or fossil fuels. from gigantic open pits at the surface. 1. Rotting 2. Heat and weight 3. Compression Dead trees rot away As they are buried The remains are and are buried in mud. deeper, the remains are compressed (squeezed) heated and squeezed. into a layer of coal, which is called a seam. Generating Gas and oil electricity Crude oil is extracted from the Fossil fuels are burned in earth by drilling. It is used to power stations to make power vehicles and make electricity. We have used plastics. Gas is also released fossil fuels to make through drilling. It is used for electricity for many years, heating buildings. There are but burning them harms limited amounts of fossil fuels — the environment. if we keep using them, they will eventually run out. Cooling towers at a power station. 110
Fossils SEE ALSO ▸▸ Dinosaurs p.80 Fossils are the remains of plants and animals from long ▸▸ Fossil fuels p.110 ago. They are usually bones or shells that have turned into ▸▸ Prehistoric life stone. Some fossils are so small that we cannot see them without special equipment. Others are as tall as a building. p.202 ▸▸ Rock cycle p.213 ▸▸ Skeleton p.228 The best fossils This dinosaur’s We only know are found in very sharp teeth tell fine-grained rock. us that it was that dinosaurs a meat-eater. Dinosaur fossil existed because we have found their Sometimes whole animals can be found as fossils. This fossil remains. skeleton belonged to a small dinosaur named Coelophysis (SEE-low-FY-sis). Complete fossil skeletons like this one are very rare. How fossils 147 million years ago 100 million years ago 2 million years ago 5 years ago are made Death Burial Turning to stone Discovery To become a fossil, A dinosaur dies and its Layers of mud, sand, and The skeleton of the Millions of years later, an animal or plant body sinks into the soft ash cover the dinosaur, dinosaur slowly turns a scientist uncovers needs to be covered mud by a river. and its flesh rots away. from bone to stone. the fossil skeleton. up soon after it dies. Turning into 111 a fossil takes millions of years.
Fractions SEE ALSO ▸▸ Astronomy p.32 Fractions are parts of whole numbers. They are written as ▸▸ Clocks p.61 one number over another number. The number on the top ▸▸ Measuring p.159 is usually smaller than the one on the bottom. Fractions ▸▸ Numbers p.185 can be used on their own or with whole numbers. ▸▸ Shapes p.222 ▸▸ Symmetry p.248 Common 1 1 Quarter fractions 2 4 A quarter is 1 part out of 4 equal parts. A whole number can 1 be split into any 8 Eighth number of parts to One-eighth is 1 part make a fraction. out of 8 equal parts. Here are some of the fractions we use most often. Half Half of a number is when it is split into two equal parts. Parts of a fraction Decimals Same but different? The top number in a fraction is Fractions can also be written as Fractions can be written differently called the numerator. The bottom decimals. The number to the left of the but mean the same. A half is the number is called the denominator. decimal point is a whole number. The same amount as two quarters. They are divided by a line. number to the right is the fraction. One half (1⁄2) 3 The numerator 0.75 This number is 4 The denominator the fraction. Two-quarters (2⁄4) Decimal Three-quarters The decimal point divides the whole number from the fraction. 112
French Revolution SEE ALSO ▸▸ Buildings p.48 For years, France was ruled by all-powerful kings, ▸▸ Money p.69 who were very rich and could do whatever they ▸▸ Europe p.94 wanted. The ordinary people of France were poor. ▸▸ Governments Between 1789 and 1799, the people overthrew the king and changed laws. p.123 ▸▸ Law p.145 ▸▸ War pp.278–279 Marie Antoinette The Bastille was used to The luxurious lifestyle of keep prisoners Marie Antoinette, the of the king. French queen, made many ordinary people Louis was angry. They thought beheaded using she did not care a machine called about their the guillotine. problems. The Bastille The Bastille was a royal prison in Paris. On July 14, 1789, a crowd attacked it and stole weapons that had been stored inside. King Louis XVI General Antoine-Joseph was killed Santerre was a leader in in 1793. the Revolution. End of the monarchy The king and queen tried to run away from France dressed as servants. They were caught and later executed in front of crowds of people. 113
Friction SEE ALSO ▸▸ Forces p.108 Friction is a force that slows down moving things by pulling against the direction of their movement. It is created ▸▸ Water between two surfaces as they move past each other. pp.120–121 Different surfaces produce different amounts of friction. ▸▸ Gravity p.125 ▸▸ Materials p.157 ▸▸ Temperature p.252 Grip or slip? Producing heat Rough surfaces grip better because If we rub our hands they create more friction than smooth together there is friction surfaces. Smooth surfaces slip past between them. They start each other because they create less to get warm because friction than rough surfaces. friction produces heat. Rubber sole Snow boots have rough rubber soles that grip, so that the climber’s feet don’t slip. Rubber grip on Smooth bottom snow boots of the ski Icy surface Icy surface Lots of friction Not much friction The icy surface and the The snow and the ski have sole of the boot have lots little friction between them of friction between them. and the ski slides easily. Skis Smooth skis slide over an icy surface very easily. They are made of many different materials, including wood and plastic. 114
Fruit and seeds SEE ALSO ▸▸ Animal groups Seeds store everything a new plant needs to start growing, including food. A fruit protects the seeds p.22 inside it. It also gives a plant a way to move its seeds ▸▸ Flowers p.103 away to somewhere they can grow. ▸▸ Eating Fruit pp.104–105 ▸▸ Plants p.194 Fruit forms from the flowers of ▸▸ Trees p.261 some plants. Fruit usually tastes ▸▸ Weather p.271 sweet, so people and animals like to eat it. Spreading seeds Plants spread, or disperse, their seeds in different ways. Apple seeds sit in a core in the middle of the fruit. Apple seeds Apple Peapod By wind Some plants have “winged” can take up to seeds that help their seeds fly away in the wind. 80 days By animal to begin to grow. Animals eat fruit, and then poop out the seeds away Peas are the seeds Leaves start from the plant. inside a peapod. to make food for the plant. Exploding pods How seeds grow Some plants have seed pods Leaves unfold that explode, flinging the and shoot seeds into the air. straightens. Many plants grow from seeds. With Shoot bursts water, the right temperature, and soil, through the soil. a seed can begin to grow into a plant. Bean seed Roots grow Shoot begins starts to to anchor to grow swell. the plant upward, in the soil. toward the light. 115
Galaxies SEE ALSO ▸▸ Gases p.117 Galaxies are enormous groups of stars, planets, dust, and ▸▸ Milky Way p.167 gas that are held together by the force of gravity. They ▸▸ Physics p.192 come in different sizes and shapes, including spiral, ▸▸ Shapes p.222 elliptical, and irregular. ▸▸ Stars p.242 ▸▸ Universe p.263 New stars form Spiral galaxy in the spiral arms. Spiral galaxies are disk-shaped with spiral arms. They are the most common type of galaxy. On average, they contain more than 100 billion stars. Our Milky Way is a spiral galaxy. Scientist think All stars The middle of the that galaxies are rotate around galaxy bulges mostly made of the center of outward. a material called the galaxy. “dark matter,” Irregular galaxy which we can’t see. Small galaxies that do not have a clear structure Elliptical galaxy are known as irregular galaxies. These may be Elliptical galaxies are created by two galaxies rounded in shape, and colliding. They contain are usually made up of lots of young stars, older stars. They are dust, and gas. generally larger than spiral galaxies. Elliptical 116 galaxies contain lots of stars but little gas or dust.
Gases SEE ALSO ▸▸ Changing states Gases are all around us—we are surrounded by a mixture of gas called air. We can keep them in sealed p.57 containers but if we open the container, the gas ▸▸ Elements p.90 escapes and spreads out. Most gases are invisible. ▸▸ Liquids p.148 ▸▸ Lungs p.149 What gases do Helium is a ▸▸ Mixtures p.168 lighter gas than ▸▸ Solids p.234 Gases have things they air, so helium do called properties. For balloons float. Blowing bubbles example, gases can be squashed and then they Soap bubbles contain a little push back to fill the original bit of air that pushes out space. This is useful for toward the bubble. The soap pumping up bike tires bubble mix is stretched but that cushion bumps in pushes back, squashing the the road as we ride. air into a sphere. Gases expand to fill their container. Gas would Fizzy drinks escape from an unsealed container. When you see bubbles in a liquid, every one of them is full of gas. In a fizzy drink, the bubbles are the gas carbon dioxide. Gas particles What’s in air? 78% 1% other gases Gases are made from tiny nitrogen 21% oxygen particles that move away Air is the gas all around from each other in all us. It is made of a The gases in air directions at top speed. mixture of different They travel long distances gases, but mostly a unless they bounce off gas called nitrogen. solid barriers. We breathe in oxygen from the air for our bodies to use. 117
Gemstones SEE ALSO ▸▸ Elements p.90 Gemstones are minerals that can be cut and polished to make jewels. They are often set in pieces of jewelry, ▸▸ Metals p.162 such as rings, brooches, and even crowns. Many gemstones, such as rubies, are brightly colored. Others, such as ▸▸ Money p.169 diamonds, are usually colorless. ▸▸ Precious metals p.199 ▸▸ Gold pp.200–201 ▸▸ Rocks and minerals p.214 Cutting gemstones Cut ruby Jewelry Gemstones are found Gems are often set as minerals. To become in precious metals, sparkly jewels, they must such as gold and silver. be cut into shape. Very They are used to sharp tools are used to make brooches, carefully cut the stone into earrings, and other exactly the right shape. pieces of jewelry. H l Uncut ruby Some gemstones, Red opa Pink ruby such as types of essonite garnet The small diamond, are worth sides made a lot of money. Purple amethyst by cutting are Blue diamond called facets. re Smithsonite Red ruby Blue sapphi Emerald Spessa rtine garnet Sugilite The sparkliest gems have the Garnet most facets. Lolite Tur quoise Different colors This rectangular Topaz Tourmaline shape is called The colors of gemstones a step cut. Unusual are often caused by shapes, such substances in minerals Diamonds as this heart, known as impurities. are called Sapphires and rubies are are made entirely from fancy cuts. both types of a mineral called corundum, with carbon squeezed impurities that make them blue or red. under enormous pressure deep within the Earth. 118
Genes SEE ALSO ▸▸ Body cells p.41 Genes are the instructions that make people the way they ▸▸ Evolution p.95 are. They include things like skin color, hair color, and ▸▸ Human body height. Half our genes come from our mother and half from our father. p.130 ▸▸ Life cycle p.146 Inheritance ▸▸ Mammals p.154 ▸▸ The sciences Face shape, eye color, and hair texture are passed pp.218–219 down from either the mother’s or the father’s If you unraveled genes. Skin color works differently—it depends on all the DNA in a the amount of a chemical called melanin in the skin. person it would reach to the sun and back 400 times! Her hair is Mother Father Her hair is curly light brown like her mom’s, and straight His eyes are His hair is black and light brown like her dad’s. brown like and curly like like her dad’s. his mom’s. his mom’s. Her face shape was passed on from her mother’s genes. Child 1 Child 2 Child 3 Her skin color could be the Clones same as either parent or Most animals get a mix of anything in different genes from their between. parents. Clones have exactly the same genes as What is DNA? another animal. Dolly the sheep was the first cloned Genes are made from long structures mammal. Her genes were called DNA. Everyone has different DNA, taken from a single cell of except for identical twins, whose DNA a female sheep. is the same. DNA looks like a twisted ladder. 119
The story of... Blue planet Water Nearly three-quarters of the Earth is covered by oceans and Water is a clear, colorless substance that is seas. Rivers and lakes stretch found all around us. It forms Earth’s oceans, lakes and rivers, snow and ice, and the clouds across the land’s surface. drifting overhead. All living things—including The polar regions, near the North us—are mostly made of water, so without it our planet would be lifeless. and South Poles, lie beneath frozen water, ice, and snow. h Planet Eart More than 96 percent What’s in water? of all the water on Earth’s surface is too Water is made up of tiny salty to drink. particles called molecules. Each one has an oxygen (O) atom joined to two smaller hydrogen (H) atoms, so water is also known as H2O. O Fish breathe using H special organs called gills to extract oxygen from the water. Water H molecule Hydroelectric dam Water power About 90 percent of all frozen water on Earth Rushing water is used to is in Antarctica, around make power at giant the South Pole. hydroelectric dams around the world. As the water moves through the dam, it turns turbine machines that spin so quickly they create electricity. 120
Stone for grinding Grain grown in wheat into flour Mesopotamia Only 2.5 percent of the Earth’s water is fresh. It is found mostly in rivers, lakes, and glaciers. Land of the rivers The first cities were built in Mesopotamia (now mainly Iraq) around the Tigris and Euphrates rivers. The rivers allowed goods and people to move around and provided essential water to drink, cook with, and use to water crops. Stone sickle for cutting crops Kayaking Water sports We lose water Without water there from our bodies would be fewer ways for us to have fun. There would be through sweating nothing to swim in or surf on, and no kayaking or sailing. There when we are active would be no snow for skiing or and play sports. sledding and we could never build a snowman. Bad for the environment More than 200 billion plastic water bottles are used around the world each year. Making the bottles releases lots of harmful gases into the air, and only one in five bottles is recycled— the rest are thrown out as garbage. Plastic water bottles 121
Glaciers SEE ALSO ▸▸ Antarctica p.24 Glaciers are slow-moving rivers of ice. They form high up in mountains or regions near Earth’s poles and flow ▸▸ Arctic p.25 downhill. The front of a glacier may melt to make a river or lake. If a glacier reaches the coast, huge blocks of it break ▸▸ Changing world off and float away into the ocean as icebergs. pp.50–51 ▸▸ Climate change p.60 ▸▸ Erosion p.93 ▸▸ Mountains p.172 How are glaciers made? The dark streaks A lake of melted ice Glaciers can wear on the surface are often forms at the down the sides of Glaciers are made from snow that builds rocks carried along front of a glacier. mountains, making up and turns into ice. Eventually, there is by the glacier. them pyramid-shaped. so much ice that it starts to flow downhill. Signs of U-shaped valley Sharp ridge Giant rocks glaciers Glaciers carve steep-sided valleys An arête is a sharp ridge of rock Glaciers can pick up giant rocks and into flatter U-shaped ones as ice that separates two valleys that dump them far from where they Some parts of the world and rock grind the hillside away. once had glaciers in them. came. They are called erratics. were once colder and covered in glaciers. As the climate warmed, the glaciers melted away. However, they left signs in the landscape that they were once there. 122
Governments SEE ALSO ▸▸ Law p.145 A government is an official group of people that runs a ▸▸ Medicine p.160 ▸▸ Trade p.257 country. Governments keep their people safe through ▸▸ School rules called laws. They often try to keep the peace with pp.272–273 other countries, and can help provide services such as schools and hospitals. Most governments try to help ▸▸ Work p.274 ▸▸ World p.275 people lead better lives. How a government works Head of state One person is in charge of Each country has its own system of government each country, such as a that looks after its people. Large countries have president or queen. They different levels of government, while smaller represent it when meeting countries have simpler systems. with other countries. Local governments National government Local governments run The national government looks after smaller areas within the whole country. It makes laws and countries. They look after has people in charge of different local issues, such as roads areas, such as education. and libraries. Electorate People in many countries choose their governments by voting in elections. They are the electorate. Types of government Constitutions Most countries in the world are democracies. A constitution is a written document They elect (choose) who is in government. that sets out the aims and values Other countries have heads of state of a country and how it should be who aren’t chosen. ruled. The US constitution was written in 1787. Democracy Monarchy Dictatorship In a democracy, people vote A monarchy is a family Dictators often rule by force. for a government and a head system in which the job of of state to rule them and take the head of state is passed They use an army to make from the king or queen to people do what they say. decisions for them. their child or relative. 123
Grasslands SEE ALSO ▸▸ Africa p.12 Grasslands are large areas covered in grass with just ▸▸ Animal homes a few trees. They are dry, but get more rain than deserts do. Grasslands are known as savannas in p.23 Africa, steppes in Russia, prairies in North America, ▸▸ Birds p.39 and pampas in South America. ▸▸ Deserts p.78 ▸▸ Migration p.166 Grassland life Hoopoes make a ▸▸ Monkeys and “hoopoe” sound Many different animals live in grasslands. as they fly. apes p.170 Some feed on the grasses and walk long distances to find enough grass to eat. Other Plains zebras live animals hunt and eat these plant-eaters. together in herds, to protect themselves Acacia trees have White rhinos from hunting animals. thorns around charge if they their leaves. need to defend Nile crocodiles attack themselves. animals that come to drink at the water. Giraffes can reach Female lions the top of the trees hunt in groups. African rock pythons to eat the leaves. squeeze to death the Milkweed locusts animals they catch. Meerkats take can be heard turns looking chirping but are out for animals not often seen. that might eat them. Insects called termites build Vervet monkeys large mounds eat berries and together. insects. Mole rats stay South Africa underground Kruger National Park in South all their lives. Africa is home to many different animals. The park sits in a huge Aardvarks have long area of grassland. It is a protected tongues to feed on area where park rangers try to termites in their mounds. keep the animals living in it safe. 124
Gravity SEE ALSO ▸▸ Forces p.108 Gravity is an invisible force that pulls us back down ▸▸ Gases p.117 toward Earth when we jump in the air. If we throw a ▸▸ Measuring p.159 ball up it comes down because of gravity. Without it, ▸▸ Moon p.171 we would float off into space. ▸▸ Solar system Falling to Earth p.233 ▸▸ Sun p.247 Earth’s gravity pulls things toward it. When a skydiver jumps out of a plane, gravity starts to pull him down. Eventually he will use a parachute to slow his fall. Air pushes up on the Gravity pulls the skydiver as he falls. skydiver down toward Earth. Earth The moon moves around the Earth. Isaac Newton Newton came up Moon with the theory of Scientist Isaac Newton gravity after Earth and moon realized there was a pattern watching apples behind objects falling fall from a tree. The strong pull of Earth’s gravity keeps toward Earth. the moon moving around it. Without 125 gravity, the moon would disappear into space.
Habitats SEE ALSO ▸▸ Coral reefs p.74 A habitat is the place a plant or animal lives. Habitats ▸▸ Deserts p.78 around the world have different temperatures and ▸▸ Forests p.109 landscapes. Animals and plants have certain features ▸▸ Grasslands p.124 that allow them to survive in their habitats. ▸▸ Polar habitats Tundra Polar regions p.197 This cold habitat Very few plants ▸▸ Seashores p.220 has very few and animals trees, plants can survive Coniferous are small, and in the freezing forest animals often temperatures This habitat is move away of this icy habitat. full of coniferous after the short trees, which summer. keep their needlelike leaves all year round. Tropical rain forests cover 7 percent of Earth, but are home to more than half the world’s plants and animals. Desert Rocks and sand cover this very dry habitat. Animals and plants have to be able to survive with very little water. Rain forest Grassland Deciduous forest Ocean Trees grow quickly in this Grasslands have more rain This habitat has four This saltwater habitat warm, rainy habitat. They than deserts, but not enough seasons. The trees drop covers 70 percent of provide food and homes for for many trees to grow. Most their leaves in autumn and Earth’s surface. Some thousands of different animals. animals here eat grass. grow them again in spring. animals live deep down. 126
Hearing SEE ALSO ▸▸ Brain p.45 Hearing happens when our ears receive a sound. Sound is a vibration that travels through the air and into our ears. The ▸▸ Communication sound travels into the hidden parts of the ear and our brain p.69 identifies what we hear. ▸▸ Human body p.130 ▸▸ Music pp.176–177 ▸▸ Radio p.203 ▸▸ Sound p.235 The ears are The ear The smallest shaped like cups bone in your ear to catch sound. The ear is much bigger than it looks is the size of a from the outside. The inner ear and outer ear are hidden inside our heads. grain of rice. Inside the ear Outer ear 2. Ear drum 3. Bones 5. Nerve The ear drum is Three tiny bones This nerve sends a tiny disk with called the ossicles sounds to the brain skin stretched pass the vibrations as electrical signals. over it. It picks up along. sound vibrations. 1. Ear canal Inner ear The curled Sound vibrates Middle ear part of the through the air inner ear is and into the ear. 4. Inner ear called the The inner ear cochlear. Brilliant brain contains liquid-filled tubes. The vibrations The brain makes sense move through the of the signals from the liquid and tiny hair ear. For example, if cells in the cochlear someone is talking to us, detect the sounds. the brain works out what the meaning of the 127 sounds are.
Heart SEE ALSO ▸▸ Body cells p.41 The heart is a pump about the size of a fist. It is mainly ▸▸ Brain p.45 made of muscle and it pushes blood around the body ▸▸ Feelings p.99 by squashing itself in and out around 80 times a minute. ▸▸ Human body Blood is a liquid that carries oxygen and food around the body. If the heart stops beating, the body stops working. p.130 ▸▸ Lungs p.149 ▸▸ Medicine p.160 Inside the heart This artery carries Circulation blood without The heart pumps blood oxygen to the lungs. Blood with oxygen in it travels every second of the day. around the body, pumped along The right side of the heart by the heart. The oxygen is sends blood to the lungs. dropped off in different places, The left side sends blood then comes back to the heart to the rest of the body. to be pushed to the lungs. Atrium Artery Vein The heart has two Heart “chambers” on each side, called atriums. Valve Valves are gates that only open one way, so blood can only travel in one direction. Blood Blood contains tiny parts called cells. Red blood cells carry oxygen and waste gas. White blood cells kill germs. Broken bits of cells stick together to make a scab when the body is cut. Vein Artery Blood arrives from Blood is pushed the body through out to the body in tubes called veins. tubes called arteries. 128 Blood vessels
Hibernation SEE ALSO ▸▸ Amphibians p.15 For many animals, finding enough food in winter is hard. Some animals migrate, or move, to warmer areas. Others ▸▸ Animal groups survive by going into a deep sleep, called hibernation. They p.22 wake up again in the springtime when there is more food. ▸▸ Day and night p.77 ▸▸ Mammals p.154 ▸▸ Migration p.166 ▸▸ Seasons p.221 Dormouse Bats hibernate upside down These small mammals make in caves cosy nests under leaves on or trees. the forest floor, or at the bottom of hedges. Bat Bats enter a deep hibernation. Their heart rate drops from 400 to 25 beats per minute. The furry tail Dormice can wraps around the mouse’s face curl up and sleep to keep it warm. for up to Wood frog seven months in a year. Wood frog Do bears hibernate? This frog’s body freezes in the winter and its heart Bears sleep in the winter, stops beating. When the but not very deeply, so weather gets warmer, its they can be woken easily. heart starts beating again This is called a torpor. It is and the frog thaws out. like hibernation, but without such a deep sleep. 129
Human body SEE ALSO ▸▸ Biology p.38 The body is made from lots of different parts ▸▸ Body cells p.41 called organs. Each organ has a different job ▸▸ Carbon cycle p.49 to do. Organs work with muscles and other ▸▸ Heart p.128 parts of the body to make important things ▸▸ Lungs p.149 happen, such as breathing, digestion, ▸▸ Monkeys and and movement. apes p.170 Body systems Respiratory system The lungs bring air into Nervous system Organs that are linked the body and send waste The brain thinks together are called systems. air out. They supply and controls body Each system has its own job, oxygen to the blood. movement. Signals but they work together, too. are sent to the brain through nerves. Body ingredients Circulatory The human body is made up of tiny parts called system cells. The cells of the body contain lots of The heart pumps different ingredients. They all have different blood around the uses in the body. body in a loop to transport oxygen Calcium helps muscles One-fourth of our and food. to work and the heart to bodies is carbon. It is Digestive system keep beating. also found in diamonds! The stomach and intestines break A tiny amount of iron Tears contain sodium Skin and hair down the food so is found in the body. It chloride, which is the system it can be used to makes your blood red. same as table salt. The skin is a power the body. waterproof layer that protects the Urinary system body from germs The kidneys clean and sunshine. Hair the blood and make keeps us warm. urine from the waste. The bladder Skeletal system stores the urine. The skeleton is a frame of bones that Muscular system protects the inner The muscles move organs of the body. all the parts of the It also allows body. They make the movement. heart pump and the lungs breathe. Phosphorus helps Over half of the body make bones strong. is made of water. Matches burn using Water is found in our phosphorus. blood and cells. 130
Imperial Japan A horned helmet SEE ALSO was part of a ▸▸ Art p.28 During the Edo period, from 1603 to samurai’s armor. 1868, Japan was ruled by a series of ▸▸ Dance p.76 powerful men called shoguns. Each ruled from the city of ▸▸ Knights p.142 Edo, which is now Tokyo. ▸▸ Musical instruments p.175 ▸▸ Theater p.253 ▸▸ War pp.278–279 Noble samurai Making music Samurai were warriors who fought Music has always played for a powerful lord and followed an important part in strict rules. Their way of life was Japanese culture. This called Bushido (bu-shi-do), “the instrument, called a way of the warrior.” shamisen (sha-mee-sen), is like a guitar. It provided The main weapon was background music for a sword called a katana. dance performances and puppet theater. Art Shamisens have Poets, painters, writers, and three strings craftspeople made beautiful and a square works of art during this time. body. This print from 1857 shows a traditional Japanese scene of Strict command trees and a river in the snow. Edo society’s chain of command was strict. The emperor was the leader, but the shogun was in charge of the lords, who were called daimyo. The daimyo were in charge of the samurai army. Emperor Shogun (sho-gun) Daimyo (die-myo) Samurai (sa-moo-rai) 131
Incas SEE ALSO ▸▸ Aztecs p.35 The Inca people lived in the mountains along the west ▸▸ Crafts p.75 coast of South America. Between 1438 and 1532 ce, their ▸▸ Farming p.98 wealthy empire was the largest in the world. Society was ▸▸ Maya p.158 well organized and everyone knew their place. ▸▸ Gold pp.200–201 ▸▸ South America p.236 Inca society The ancient Inca city of Machu Picchu At the head of Inca society sits in the Andes was an emperor called Sapa Mountains, in Peru. Inca, meaning “Great Inca.” Most people were peasant farmers who worked for the emperor and in return were given food and housing. The Sapa Inca Sun god was treated like a god. He was This gold disk shows Inti, carried in a chair the Inca god of the sun. by servants. Every year the Incas held a nine-day festival of eating, drinking, and sacrifice to honor the sun god. Houses were Inca crafts made of stone and had thatched roofs. The Incas made sacred objects from gold and silver Everybody had to be used in temples. to bow down to Craft workers also made the Sabu Inca. fine pieces from clay, leather, and feathers. Farmers planted potatoes. Llamas were Maize, or corn, was Gold llama used for carrying an important food. goods and for their wool. 132
Industrial Revolution SEE ALSO ▸▸ Buildings p.48 The Industrial Revolution was a time of huge growth in ▸▸ Engines p.92 industry brought about by the introduction of new ▸▸ Factories p.97 machinery. Factories were built to make products using ▸▸ Inventions large numbers of machines. The revolution began in Britain during the 1760s and later spread around the world. pp.136–137 ▸▸ Machines p.150 ▸▸ Pollution p.198 Factory work Steam trains Chimneys Steam engines transported goods and belched out were used to Factories contained rows of fuel, such as coal, to smoke all day. power ships. machines that made things in large and from the factory. amounts, such as textiles, iron and brass goods, pottery, and glassware. These machines were powered first by water and then by steam. Barges traveled on canals carrying goods between towns. Workers lived Child labor in small, overcrowded Children as young as four houses. worked in the factories and mines. The work was Small towns grew Horsedrawn carts often dangerous and Boys working in a cotton mill up quickly around carried supplies to dirty. Children also swept in Georgia, 1900 the factories. the factory. chimneys and ran errands. They worked up to 80 hours a week, but were paid very little money. 133
Insects SEE ALSO ▸▸ Animal groups Insects are the largest group of animals, and are found all over the world. They have three pairs of legs and a tough p.22 outer covering, called an exoskeleton. Many insects have ▸▸ Eggs p.86 wings and can fly. ▸▸ Invertebrates Butterflies Swallowtail Feelers called antennae p.139 butterfly help the butterfly ▸▸ Metamorphosis A butterfly changes a lot in its to smell nectar and life cycle. It starts as an egg, then stay balanced. p.163 hatches into a caterpillar. It wraps ▸▸ Migration p.166 into a chrysalis before hatching again as a butterfly. Many insects have wings, which let them fly around. There are Body parts more than Insects’ bodies are divided 900,000 into three parts: the head, different types the thorax, and the abdomen. of insects They have three pairs of legs in the world. attached to the thorax and one pair of antennae on Red wood ant their heads. Ants Thorax Ants live together in groups called Patches of color on Head Abdomen colonies, with thousands of the butterfly’s wing tell workers and a queen. They other animals that it is are small but strong—ants can not good to eat. lift 20 times their body weight. Desert locust Stag beetle nymph Beetles Grasshoppers Beetles are found on land and These insects can leap in water all over the world. They 20 times their body length. have hard, shiny outer wings They can also fly fast, that close over a soft inner set reaching speeds of up of wings, to protect them. to 8 mph (13 kph). 134
Inside Earth SEE ALSO ▸▸ Compass p.70 The Earth is made up of four layers. We live on its outer ▸▸ Earth p.83 ▸▸ Earth’s surface layer, or crust. The crust floats on a layer of extremely hot p.84 rock called the mantle. Below this, our planet’s center, or ▸▸ Magnets p.151 ▸▸ Metals p.162 core, is made of the metal iron. The upper mantle ▸▸ Volcanoes p.268 is made of hot, partly liquid rock. In our planet’s early history, it had Earth’s layers no crust and the Like an onion, the Earth has layers. Each layer is different. The deeper mantle was a sea of the layer, the hotter it is, with the inner core a scorching 10,800°F bubbling liquid (6,000°C). rock. The outer core is made of liquid iron. The inner Earth’s crust core is a ball is made of of solid iron. solid rock. The lower mantle is Magma made of hot, solid rock. and lava Magnetic Earth Main opening In some places on the Earth’s surface, liquid rock Because the Earth’s outer core is Magma bubbles up to the surface, liquid, it moves as the Earth spins. chamber creating volcanoes. Liquid This creates a magnetic field around the Earth. This field keeps rock is called magma out harmful energy waves from when it is inside the space. It also lets us find directions Earth and lava on when we use a compass. the surface. 135 Lava flows North South Pole Pole Magnetic field
The story of... Steam engine Inventions The first steam engines were used to pump water Inventions are new ideas that solve problems out of mines. Later, engines or prove useful to us. Thousands of years of were used to power brilliant brainpower have resulted in things factories and trains. George and ideas that have transformed people’s Stephenson’s Rocket train lives. Even in the modern world, people keep was built in 1829. coming up with new ideas and inventions. Reaching 30 mph Hard flint was Hand axe broken down (48 kph), the Rocket was to make sharp The hand axe was the first vehicle to tools. the first stone tool in prehistoric times. People dug travel faster than for flint, which they shaped into a horse. handcrafted axes to cut meat, chop wood, scrape skins, and protect themselves. Hand axes were used for more than a million years. A rod, or axle, links the A tall chimney wheels together— released turning the axle uses steam from much less energy than the engine. turning the wheel. Wheel The front wheels were The wheel was pushed around invented more than by the engine. 5,000 years ago in Mesopotamia (part of modern-day Iraq). Wooden 136 discs were attached to animal carts to carry heavy loads. Later, wheels became lighter, which made them faster and smoother.
The Wright’s Flight Flyer, built in 1903. In 1903, American brothers Wilbur and Orville Wright built a glider with a light engine. Although Flyer took off for only 12 seconds over 120 ft (37 m), it was the first-ever powered flight. Plastics Antibiotics Antibiotic pills Plastics are cheap to make, Infection-fighting easy to shape, and last a long antibiotics battle bacteria inside time. They can be hard, soft, or the body. They were discovered by bendy. The first human-made accident in 1928, when Scottish plastic was made by Belgium-born scientist Alexander Fleming noticed chemist Leo Baekeland in 1905. bacteria dying around mold in his lab. The bacteria-killing chemical Now plastics are all around us. penicillin has since saved many lives. Thomas Edison (1847–1931) was an American master of invention, patenting 1,093 ideas in his lifetime, including batteries and light bulbs. Computers Computers are electric machines that follow instructions. Modern computers can do billions of sums every second. We use The first them to find, store, and share electronic computer, information. The idea of a computer was invented by ENIAC, was huge, English engineer Charles Babbage in the 1830s. filling a room measuring 50 ft (15 m) long. 137
Internet SEE ALSO ▸▸ Codes pp.66—67 The Internet is a network that links together computers all over the world. We use it to learn things, for ▸▸ Communication entertainment, and to communicate with each other. p.69 The Internet was first thought of in 1962. Now, billions of people use it every day. ▸▸ Computers p.71 ▸▸ Satellites p.215 ▸▸ Telephones p.250 How the Internet works The cloud Information kept somewhere remote The Internet is made up of digital rather than on your computer is said information stored on computers. to be “in the cloud.” This information The information can be uploaded can be anything, such as facts, online or downloaded through a network. games, news stories, or music. Wi-Fi Satellite Wireless Internet Satellites send works using radio information signals. between phones and the Internet. Smartphone Smartphones are small, handheld computers that can connect to the Internet. Connection Website servers Computers can connect to the Internet using cables A website is a collection of linked pages. that connect to Internet Each website has a unique Internet service providers. address called a URL. Websites are stored on computers called servers. Internet service provider Companies called Internet Web page service providers have massive computers. These computers provide quick access to the Internet. Computer A laptop or desktop computer can store information and access the Internet. 138
Invertebrates SEE ALSO ▸▸ Animal groups Invertebrates are animals that don’t have backbones. p.22 They are divided into many smaller groups, such as ▸▸ Animal homes insects and mollusks. Ninety-eight percent of all p.23 ▸▸ Habitats p.126 animals are invertebrates. ▸▸ Insects p.134 ▸▸ Vertebrates Antennae on the head are used to “feel” p.266 movement in the air. The hard shell Insects Wings are protects the attached to snail’s soft body. Insects have a tough outer the body. covering. They have six legs and many can fly. Praying mantis Front legs Snail catch smaller Worms can eat insects to eat. Mollusks their own body The body looks Mollusks have soft bodies with no like a dead leaf, to weight in food skeleton and no legs. They live in make the mantis in one day! water or wet soil. hard for other animals to see. Earthworm Worms Worms have long soft bodies with no legs. Their bodies are split into many parts, or segments. Pincer claws Venomous sting Hard outer shell Starfish Scorpion Crab Suckers underneath Arachnids Crustaceans help the starfish cling These animals have eight legs, not six Crustaceans have hard outer shells, to rocks. like insects. Arachnids include spiders, and more than eight legs. Most of scorpions, and mites. them live in water. Echinoderms 139 These animals have bodies split into equal parts around a disk in their middle. They all live in the sea.
Iron Age SEE ALSO ▸▸ Bronze Age p.47 During the Iron Age, people began using iron ▸▸ Farming p.98 tools and weapons instead of bronze ones. ▸▸ Metals p.162 It started about 3,200 years ago and lasted ▸▸ Rocks and for around 1,000 years, depending on the area. Iron tools were stronger and more minerals p.214 durable than anything before. ▸▸ Trade p.257 ▸▸ Vikings p.267 Tools Weapons Iron tools allowed farmers and builders Iron weapons were lighter and to work better. They were able to grow cheaper to make than weapons more crops, clear land for farms, made from bronze. Well-made iron and build bigger buildings. weapons were also stronger and sharper than bronze ones. Having good weapons meant societies could build powerful armies. This iron sickle would Hill fort have been attached to a wooden handle and Hill forts are Iron Age used to cut wheat. villages built on the top of hills. They had Iron cutting edge Danish iron earth or stone walls Iron Age hill fort in sword from the around them. Hill forts Dorchester, UK Making a sword was Viking period of allowed people to see very difficult. The 800–1100 ce the enemy approaching best swordmakers and prepare themselves were well paid. for attack. The walls at the base of the fort acted as a protective barrier. Making iron 1. Dig it out 2. Heat it up 3. Pour it in Iron is dug from the ground The iron ore is heated to high The melted iron is poured into Making iron items is a in lumps, called iron ore. temperatures to make it melt. a shaped mold and left to cool. process that needs great skill and care. The iron must be made extremely hot before it can be shaped into a weapon or a tool. How we shape iron today is similar to how Iron Age craftsmen performed the task. 140
Jupiter SEE ALSO ▸▸ Astronomy p.32 Jupiter is the largest planet in the solar system, and ▸▸ Atmosphere p.33 the fifth planet from the sun. It is a “gas giant” made ▸▸ Elements p.90 of hydrogen and helium. Jupiter does not have a ▸▸ Gases p.117 solid surface like Earth. ▸▸ Solar system p.233 ▸▸ Solids p.234 King of the planets ▸▸ Storms p.246 Jupiter is so large that 1,300 Earths could fit inside it. A huge storm in its atmosphere, called the Great Red Spot, is more than twice the size of Earth. Jupiter is the third brightest object in our night sky after the moon and Venus. Scientists have Io Europa Ganymede The striped bands and been watching 141 swirls are shaped by the Great Red strong winds. Spot storm since 1830. Callisto Winds swirling around the Great Red Spot reach speeds of more than 250 mph (400 kph). The Galilean moons Jupiter has more than 60 moons of different sizes. Its four largest moons are called Io, Europa, Ganymede, and Callisto. They are known as “the Galilean moons” because they were discovered by the Italian scientist Galileo Galilei in the 17th century.
Knights The helmet SEE ALSO was shaped ▸▸ Castles p.53 Knights were men who owned big pieces to help avoid ▸▸ Clothing pp.62–63 of land in Europe between the 600s and direct attack. ▸▸ Europe p.94 the 1600s, a time period known as the ▸▸ Flags p.102 Middle Ages. They trained from age ▸▸ Metals p.162 seven to be fighters and lead armies. ▸▸ Sports p.239 ▸▸ War pp.278–279 Armor Knights carried Knights wore suits of armor to protect them their shield on from enemy weapons, such as swords. The first a strap when armor was made of mail, which is rings of metal not using it. linked together. Later armor also included sheets of shaped steel. Curved armor protected the knight’s elbow. Squires Steel gloves were made of Each knight had a squire to more than 40 assist him. Squires looked metal pieces. after their knight’s armor, sharpened his weapons, and A belt held the cared for his horse. Some knight’s sword squires later became knights. and dagger. Knights wore Mail was heavy to Designs colorful outfits wear, but offered for jousting. good protection. Each knight had a special design passed down to him by his father. Knights put their design on their shield so others would recognize them in battle. Men called heralds recorded which knight had which design. Jousting At jousts, crowds watched as knights on horseback raced at each other holding blunt, wooden sticks called lances. They scored points by hitting the other knight or knocking him off his horse. 142
Lakes SEE ALSO ▸▸ Climate change A lake is a large body of water surrounded by land. Most lakes contain fresh water, but some are salty. p.60 Lakes are usually found in high areas or near large ▸▸ Factories p.97 rivers. The water in lakes comes from streams or ▸▸ Farming p.98 rivers around them. ▸▸ Water pp.120–121 ▸▸ Rivers p.211 How we use lakes ▸▸ Water cycle Lakes provide water for factories, farming, p.270 energy, sports, and homes. Nearly all lakes are natural but some, known as Oxbow lakes reservoirs, are made by people. Rivers sometimes change their Lakes form when course. When they do, bends in them water fills hollows may become cut off to form U-shaped in the landscape. bodies of water called oxbow lakes. A deep bend, or meander, forms in the course of the river. Lakes provide water for us The river to drink, wash up, and bathe makes a and shower. shortcut and changes its course. Many lakes have an outlet, An oxbow such as a river, from which lake forms as the river’s water leaves. new course separates from it. Wet or dry? Lakes can dry out if there is a long period without rain, called a drought, or if the climate changes. They may reappear when the rain returns or stay dry forever. Lake water is used for farming, making goods, and producing electricity. 143
Language SEE ALSO ▸▸ Ancient Rome Language is how people communicate. Across the world, people speak many different languages. There are more p.20 than 7,100 in total, some spoken by millions of people and ▸▸ Storytelling others by just 100. These languages often sound very different from one another, and can look different pp.42–43 when written down. ▸▸ Books p.44 ▸▸ World p.275 The most-spoken languages nee-how ▸▸ Writing p.280 There are almost 7.5 billion people in the Hola Mandarin world today. About one-third of them This is the most speak one of five languages, which are spoken language used by countries all over the world. in the world. Forms of Mandarin Hello Chinese are used all over China. marr-hah-bah o-la nuh-muh-stay Arabic Hindi English Spanish This is spoken This is one English is now This is spoken in across North of the official spoken in every Spain and parts Africa, the languages of continent and in of South and Middle East, and India. It is also an many countries, Central America, in many other official language including eastern Asia, countries. in Fiji. the US. and Africa. 295 310 360 405 955 million million million million million Sign languages Dead languages People sometimes use hand shapes, body Some languages die out when movements, and facial expressions to talk, their speakers start using another language. Latin rather than spoken language. This is called a was once spoken in the sign language. It is useful if someone cannot Roman Empire, which included much of hear or speak. ”Yes” in American Europe. It’s now a sign language dead language, but ”No” in American sign language can still be read and written. Latin words from the Roman Empire. 144
Law SEE ALSO ▸▸ Changing world Laws are official rules for people to follow. The government writes laws for the whole country. Some pp.50–51 laws stop people from doing bad things (crimes), such as ▸▸ Codes pp.66–67 stealing. These are called criminal laws. Other laws try to ▸▸ Governments improve life, such as making sure people are paid a fair amount of money for doing work. p.123 ▸▸ Trade p.257 Law court Defendant ▸▸ Work p.274 The defendant is the ▸▸ World p.275 If someone doesn’t follow person who is said to have the law, they can be punished. committed the crime. Judge A criminal law court is where The judge controls the it is decided if someone has Defense court, and may give the committed a crime, and if Defense lawyers try to stop defendant a punishment, they should be punished. the defendant from being such as imprisonment, if This process is called a trial. punished by arguing for them. they did the crime. Prosecution Witness Prosecuting lawyers try A witness is to make the judge and jury someone who believe that the defendant knows something did the crime. about the crime. They tell the court what they know. In the UK, Public Jury Ordinary people are A group of usually 12 it is against allowed into courts to see ordinary people hear the law to what decisions are made. about the crime and decide if the defendant deliberately disturb did it. someone by Hammurabi’s laws knocking on their front door. Police First laws The police make sure people Police cars travel One of the earliest sets follow laws. They capture people at high speeds to of laws was drawn up who might have broken catch criminals. by King Hammurabi of laws. This is called Babylon, who ruled putting someone from 1792 to 1749 bce. under arrest. There are 282 laws about the family, trade, and wages. Police car 145
Life cycle SEE ALSO ▸▸ Body cells p.41 Like all animals, humans are born, grow up, and can have children of their own. This is called a life cycle. There are ▸▸ Cells p.56 many different stages that a human goes through on their journey from birth to adulthood. ▸▸ Genes p.119 ▸▸ Human body p.130 ▸▸ Metamorphosis p.166 ▸▸ Skeleton p.228 Baby Toddler Babies are very small and Toddlers learn how to walk, can’t feed themselves or talk. talk, and feed themselves. They need parents or carers They grow teeth called milk to take care of them. teeth, which fall out and are replaced with adult teeth. Growing up Child Children grow Everyone starts life as just and learn quickly. two cells. We grow into They are smaller than adults and children and eventually adults. still have a lot of skills to learn. Sperm and egg A sperm cell joins Unborn baby an egg cell inside the mother’s womb. Babies grow inside the After nine months, mother’s womb. Doctors look the cells have grown at the growing baby using a into a baby. process called an ultrasound. At 12 weeks a baby is about The the size of a lime. oldest person Teenager Chemical signals called recorded died at 122 hormones tell the body to years and 164 start changing from a child days old. into an adult. Adult 146 Adults can make their own children. Males produce sperm cells and females produce egg cells.
Light SEE ALSO ▸▸ Color pp.26–27 Light is a type of energy that bounces off objects and into ▸▸ Energy pp.88–89 our eyes—we need it to see things. Light can change into ▸▸ Invertebrates other types of energy such as heat or electricity. Dark is the absence of light. p.139 ▸▸ Materials p.157 ▸▸ Sight p.226 ▸▸ Sun p.247 White light The light bends Light sources as it hits the White light is actually made from all prism. This is The main source of light the colors of the rainbow. We can called refracting. on Earth is the sun. split white light into colors by Artificial light sources shining it through a prism. White light is split include light bulbs, into seven colors. candles, and oil lamps. Light travels in Some animals, such as straight lines. jellyfish and fireflies, produce their own light. The sun is a natural light source. Shadows Reflection A candle is an artificial light source. A shadow is a dark area where light More light bounces off shiny is blocked by an object. It takes the surfaces like mirrors or still water. Some jellyfish can shape of the object blocking the light. This is called a reflection. glow in the dark. 147
Liquids SEE ALSO ▸▸ Atoms p.34 Liquids are runny materials. They can be poured into things, and move to fit the shape of their container. ▸▸ Changing states Liquids make a pool, not a pile. We drink liquids including p.57 water. When a liquid cools, it can become a solid. Heating a liquid can create a gas. ▸▸ Gases p.117 ▸▸ Rivers p.211 ▸▸ Solids p.234 ▸▸ Water cycle p.270 What liquids do Around The things a liquid can do are called 75 percent its properties. For example, liquids can be heated to cook things. of your brain Liquids are good at mixing because is made of of the way they flow and move. Some liquids flow more easily water. than others, but they all change shape to fit Dissolving their containers. Some materials dissolve (disappear into) Liquids can liquids. If we add salt to water, it becomes be poured. salty water. We can’t see the grains of salt because they have dissolved into the water to make salt water. Water Salt Salt water Liquids move Water to fit the shape of their Two-thirds of the Earth’s surface is covered container. in water. Water is essential because living things need water to survive. Animals drink water and plants take water in from the ground or air. Most living things are made up of at least half water. Liquid particles Liquids are made from tiny particles that move around quickly and stick together in groups. When they cool, they slow down to eventually become solid. 148
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