Science Squad

Science
squad

Written by Lisa Burke
Consultant Professor Robert Winston

Senior editor Sam Priddy Contents
Senior art editor Fiona Macdonald
Designer and illustrator Bettina Myklebust Stovne 4 Introduction
Additional editing Jolyon Goddard, Katy Lennon, 6 Meet the Science Squad
8 The Universe
Megan Weal, Amina Youssef 10 The Solar System
Managing editor Laura Gilbert 12 Our super Sun
Managing art editor Diane Peyton Jones 14 The Earth
16 The Earth’s atmosphere
DTP designer Rajesh Singh 18 The Moon
Jacket designer Elle Ward 20 The water cycle
Producer, Pre-Production Rebecca Fallowfield 22 Solids, liquids, and gases
24 The weather
Producer Isabell Schart 26 Dangerous planet
Creative director Helen Senior 28 Animals
Publishing director Sarah Larter 30 Plants

Educational consultants Jacqueline Harris,
Trent Kirkpatrick

First published in Great Britain in 2018 by
Dorling Kindersley Limited

80 Strand, London, WC2R 0RL

Copyright © 2018 Dorling Kindersley Limited
A Penguin Random House Company
10 9 8 7 6 5 4 3 2 1
001–305910–May/2018

All rights reserved.
No part of this publication may be reproduced,
stored in or introduced into a retrieval system,
or transmitted, in any form, or by any means
(electronic, mechanical, photocopying, recording,
or otherwise), without the prior written permission

of the copyright owner.

A CIP catalogue record for this book
is available from the British Library.

ISBN: 978-0-2413-0185-2

Printed and bound in China

A WORLD OF IDEAS:
SEE ALL THERE IS TO KNOW

www.dk.com

32 Evolution 60 Materials
34 The Arctic food web 62 Building bridges
36 Ecosystems 64 Take to the skies
38 Inside a rainforest 66 Floating and sinking
40 Climate change 68 Friction
42 Microlife 70 Electricity
44 The human body 72 The Internet
46 Think about it 74 Robots
48 The senses
50 Technology 76 Glossary
52 Simple machines 78 Index
54 Time 80 Acknowledgements
56 Measuring
58 Using numbers

Introduction

This book is about science and how it’s used.
Science is about trying to understand our
surroundings – the world and Universe around
us and all the things and creatures in it, from
atoms to huge mountains, from tiny bacteria to
large whales. As we learn more, we find so
much that is puzzling. What lies outside the
Universe we can see with a telescope, and how
does the brain think and feel love?

It is important to know as much
about science as we can so that we use
our inventions, our technology, wisely. They
can be used for the good of everybody, but
science used in the wrong way can be
harmful. You are fortunate because we now
know so much more than when I was a child,
and books like this did not exist. Properly used,
the knowledge that science brings helps us to
be healthier and to live better lives.

Professor Robert Winston

MSeceitethne ce Squad

The Science Squad is made up of different
subjects that work together to show you how
the world works.

Science Technology Engineering

is all about asking questions uses science to create new is all about finding and designing
and discovering the answers machines and more effective solutions to problems – using
to explain how things work. ways of doing things. science, technology, and maths.
6

We’ll be here to
help you with
handy tips!

Art Maths

is all about using your is about numbers,
imagination and style to patterns, and
create brilliant new things. problem-solving.

7

TUheniverse

The Universe is everything around us.
Some of this we can see, but most we
cannot. It is a huge expanse of mainly
empty space, with billions of galaxies,
each containing millions of stars.

The Big Bang Light travels really fast, but space is so
enormous that it takes time to reach us. This
Astronomers believe the Universe means that when we look into the Universe, we
exploded out of a tiny point about are only ever viewing the past! Light travels
14 billion years ago. This is known nearly 10 trillion km (6 million miles) a year.
as the Big Bang. Before this, the Scientists call this a light year, and use it to
Universe did not exist. It is still
continuing to expand today. measure the huge distances in space.

There are more stars
in the Universe than
grains of sand on all of
the beaches on Earth.

8

The Hubble Telescope
travels 600 km (370 miles)
above the Earth. It took this

photo of the Universe!
Astronomers are
scientists who
study space.

It can get really cold
in space because the
stars and galaxies
are so spread out.

Our Solar System was
formed billions of years

after the Big Bang.

9

SThye Ssotlaerm

The Solar System is made up of our nearest
star, the Sun, and everything that orbits, or
travels around, it. This include planets, moons,
comets, asteroids, smaller rocks, and dust.

Sun People have
The Sun is a kind invented ways to study
of star that scientists and travel around our
call a yellow dwarf.
Solar System.

Our star Mercury is the
smallest planet in
The Sun is a medium- the Solar System. Earth is the only
sized star. The Sun’s It’s a little bigger planet that we
powerful force of than our Moon. know for sure
has life on it.
gravity pulls on the Earth
planets, keeping them teroid belt
in orbit around it.
Mercury
Mars is known as
Venus the “Red Planet”
as its dusty surface
As
contains rust.
Scientists think the
Mars asteroid belt contains
the leftover rocks
Venus has thousands Many spacecraft have from when the planets
of volcanoes on its surface. visited Mars to study were formed.
its weather, surface,
10 and rocks.

If it was possible, it would The Kuiper belt is Kuiper belt
take a jumbo jet about a very distant part of Pluto
400 years to fly from the Solar System. It is
Earth to Neptune. the home of icy dwarf Pluto is the largest
planets and comets. dwarf planet in the
Satur Kuiper belt.
Neptune is theNeptune
Saturn has more
than 50 moons. It furthest planet from
is most famous for the Sun, which makes
its rings, which are it freezing cold!
made of lumps of
ice and rock. Uranus
n
Unlike the other Launched in 1977, the
planets, Uranus spins space probe Voyager 2
on its side. This might reached Neptune in 1989.
have been caused by
a collision with an
Earth-sized object.

Jupiter is by far the Milky Way
largest planet in our
Solar System. It is Our Solar System is part of a galaxy called
made mostly of gas the Milky Way. It is spiral in shape and has
and has more than more than 100 billion stars. Scientists think there
60 moons orbiting it. is a huge black hole, sucking in dust, gas, and
light, at its centre.

Jupiter

Jupiter is so huge that You are here!
all the other planets
in the Solar System 11
could fit inside it.

Solar flares
Gigantic explosions on
the Sun’s surface blast
energy outwards. These
are called solar flares.

Sunspots
Dark, cooler patches that
develop on the Sun’s
surface are known as
sunspots. They often
appear in pairs and
last a few weeks.

Our super SunahTmthhyneaedesrcSsnoeiuovgnneretrmniebsoaaooulnflusdoorafunhmrbeeouSaliruournenlmaistntr,ogswSftagyhesraintcseaehemnrsgpd,.yrmI.iottdoissuisttacslyeast The surface of the Sun
is a sizzling hot 6,000°C
12 (11,000°F ). That’s 30 times

hotter than an oven!

At the Sun’s core,
temperatures
soar to around
15 million °C
(27 million °F)!

Total solar eclipse

A total solar eclipse
occurs when the Moon
passes in front of the
Sun and covers its
face perfectly. This
blocks out most of the
light, making it appear
as if it is night-time.

Solar prominences Some sunshine is good
Huge eruptions from the for us. We need it to make
Sun’s surface are called vitamin D, which helps our
solar prominences. They
form loops due to the Sun’s bones stay healthy.
invisible magnetic field.

Lightning 8 minutes It takes eight minutes
speed for the Sun’s light
to reach Earth.
Light travels really fast, but it still
takes time to get to us on Earth. A Solar panels
light year is the distance a beam
of light would travel in one year. 13

Life on Earth

Animals and plants depend on energy
from the Sun to survive. Technology,
such as solar panels, has been
developed to absorb the Sun’s
energy and turn it into electricity.

he oItnislyejuSpstuoltantsnhufeeortvrive.
prlikaEgnnahtotrstwdhainisnttsdoaonacucnorienfthmraaoiolsnmmletifhae.ndThe Earth t Summer happens in
the northern half of the
world when that part is
tilted towards the Sun.

Sun rays Countries near the equator
have a wet and a dry season,
The middle of the planet, rather than spring, summer,
the equator, gets a fairly
constant amount of autumn, and winter.
direct sunshine.

Seasons Earth’s axis is tilted
at an angle of 23.5˚.
We have different seasons on
Earth because the planet is slightly
tilted. This means that at different
times of the year different parts of
the planet are closer to the Sun.

14

Land takes up In Crustre
about one-third of Upper Mantle
the Earth’s surface. Lower Mantle
It is colder in the winter
because the sunlight Outer Core
is weaker. ner Co

Inside the Earth

The Earth is made many different layers,
a bit like an onion. The rocky outer
layer is the crust. The upper and lower
mantles consist of hot rock, while the
outer and inner cores are hot metal.

Stardust

Everything on Earth is made
from materials that were created
when dying stars exploded. Even
you are made of stardust!

Oceans make up most
of the Earth’s surface,
so our planet looks
blue from space.
The Earth spins around an
imaginary line through its middle,
called an axis, once a day. This is
why we have day and night.

15

aThtemEaortsh’ps here

The atmosphere is a blanket of gases that surrounds
and protects the Earth. It keeps us warm, blocks
some of the Sun’s harmful rays, and helps
stop space rocks from hitting us.

Auroras Auroras happen
These dazzling coloured lights when tiny particles from
dance in the night sky in places the Sun hit particles in
close to the North and South
Poles. They are also called the our atmosphere.
northern and southern lights.

Meteorites Weather balloon
Space rocks that make it Launched every day,
through our atmosphere and weather balloons help
hit the ground without burning forecasters predict the
up are called meteorites. weather. The balloons
carry small tools to
measure things, such
as air temperature
and wind speed.

Planes fly high up, where Aeroplanes
the air is thinner. This means Planes usually cruise at about
9–12 km (6–8 miles) high. There
they can travel easier and are often strong winds at these
faster, and burn less fuel. heights, which can make flights
turbulent, or bumpy.

16

Exosphere Astronauts have flown out
several times to service the
Scientists divide our atmosphere
into five main layers. The exosphere Hubble Space Telescope.
is the outermost layer before outer
space begins.

Thermosphere Hubble Space Telescope
Launched in 1990, this
This layer protects us by space telescope travels
absorbing a lot of the around the Earth, taking
dangerous energy from amazing photographs of
the Sun, such as X-rays. distant stars and galaxies.

Mesosphere International Space Station
This space station has a crew of up
Most space rocks that enter to six astronauts. Each stays about
the atmosphere burn up in six months, looking after the station
the mesosphere. The top of and doing experiments. It orbits the
this layer is the coldest part Earth once every 90 minutes.
of the Earth’s atmosphere.
Venus’s atmosphere
Stratosphere
Venus’s atmosphere contains thick layers
The stratosphere contains the ozone of deadly sulphur-containing clouds. Heat
layer. Ozone is a form of oxygen. from the Sun becomes trapped below
It stops harmful ultraviolet rays from these clouds. This makes Venus the
the Sun reaching the Earth. hottest planet in the Solar System.

Troposphere

All of our weather happens
in the troposphere. It contains
most of the air we breathe and
a lot of water, including clouds.

Venus’s clouds trap heat The gas carbon
below them. dioxide makes up 96.5%
of Venus’s atmosphere.

17

ThisEeoaMrrbtohit.oinnLegit,s’soatrastkmreaavalel,lclilrnoogscekaryrloowuoonkr.dld, tthheat

oon Last manned
Moon landing
The M
Apo15llo 30 July 1971 Apollo 11 December 1972
crater 17

Do you like my space Apollo 20 July 1969
buggy? The proper name 11
for it is a lunar roving
First Moon Apo16llo 21 April 1972
vehicle and it runs landing
on batteries.

Apollo
12
Apollo
14
5 February 1971
19 November 1969

Moon Moon
landings

Humans first set foot on
the Moon in 1969. The flags
show where each Moon mission
touched down on the surface.

18

There is no air on the Orbiting the Earth
Moon, so astronauts have
to wear spacesuits so they The Moon travels around the Earth about
once every 27 days. The Moon appears
can breathe. to change shape in the sky depending
on which parts of it are lit by the Sun.

The Moon The Earth

Apollo
spacecraft

mosiTstehvtpeehoreSwabelatruurfilugrtnle. srVtocarknoedctket

Rockets travel at about
35,400 kph (22,000 mph).

That’s pretty fast!

Rocket power

To get to the Moon, humans
had to first develop a rocket
powerful enough to launch the
Apollo spacecrafts into space.

Ladies and gentlemen, The heat produced
I present the Saturn V by a rocket could
heat 85,000 homes
rocket! for a day!

19

wTheater cycle The Sun plays a key part
All the water on Earth moves around in a in the water cycle. It heats
cycle. It rises into the air as moisture and the Earth, causing liquid
clouds. Rain and snow bring it back to the water to become gas.
Earth. It then flows along rivers into the
oceans, and the cycle goes on.

Water droplets Clouds
freeze into ice
crystals in very As water vapour rises, it cools
high clouds. into tiny liquid droplets, which
gather to form clouds. This
Evaporation process is called condensation.

Oceans, rivers, and lakes are Water has been used to
warmed by the Sun. As they heat transport people and goods
up, liquid water at the surface turns for thousands of years.
into water vapour, which is a gas.
This process is called evaporation.

Seawater contains
minerals, which is why

it tastes very salty.

20

Rain and snow

When a cloud holds enough
water droplets or ice crystals,
it makes rain or snow. This
water falls back to Earth.

Winter sports
such as skiing rely
on a good amount
of snowfall!

Rainwater is almost pure Back to the sea
water, except where it has
been polluted by fumes from Rainwater flows over and under
the Earth, slowly making its way
vehicles and factories. back to the oceans. The water
Dams are built to break picks up minerals on its journey.
the flow of rivers. We
do this to create lakes, Groundwater is water in
generate electricity, the soil or rocks in the
or prevent floods. ground. It may flow in

underground rivers.

21

Saonlidds, lgiqauisdse, s

Everything around us is a solid,
liquid, or gas. They are all made
of something we call “matter”.
This, in turn, is made up of
tiny particles called atoms
and molecules.

Liquids The molecules in a
liquid are close but
If you can pour something, aren’t held together
then it’s probably a liquid. as strongly as in a
Liquids take on the shape solid. This lets them
of the container they’re in. move past each
However, they’re hard to other, or flow.
squash down.

22

Gases Gas molecules are
spread out and move
Gases are all around us – the air is about very quickly.
made up of gases. A gas will fill
any container and can be squashed.
Most gases are invisible.

Condensation Solids
When a gas cools, it
turns into a liquid. Solids feel firm and are
This is condensation. hard to squash. This book is
If you breathe out solid, and so are things that
water vapour onto a you can hold, wear, or sit on.
cold surface, such as
a window, it condenses
into water droplets.

Evaporation The particles in a solid are Freezing
When they are heated, packed together so tightly A liquid freezes to a
molecules jump out of that they make a fixed shape. solid at a temperature
liquids and become called the freezing point.
gas. This is called Melting
evaporation. When a solid heats up, its particles
vibrate. When it reaches a temperature
called the melting point, its particles
break free and become liquid.

23

wTheeather
The weather affects what people do
everyday. One of the reasons it happens Thunder
is because the Sun heats up the air, and lightning
causing it to move around. This creates
lots of different types of weather. Thunderstorms are electrical storms
that normally happen in hot, humid
Snow Snowploughs clear weather. Lightning is like a giant
heavy snowfall to electrical spark. Thunder is the
When cloud temperatures are 0°C make travel easier. sound caused by lightning.
(32°F) or below, water droplets in
the clouds freeze. They form delicate Can you paint all
ice crystals and fall as snow! the colours of
the rainbow?

Rain

Clouds are made up of
millions of water droplets
that fall as rain when they
get too heavy. Rainbows
form when it is raining and
sunny at the same time!

Snow chains are put
on winter tyres to give
vehicles more grip.

24

Large solar panels
and batteries
power satellites.

Sun Weather
satellites
Some parts of the Earth get
more sunshine than others. Weather satellites help
That’s why it’s cold at the forecasters to see what
North Pole and hot in the the weather is doing.
Caribbean. This makes it easier to
predict how it might
These satellites watch move or change in
storms as they move the near future.
across the Earth.
Special instruments
Fog help pilots to land
planes safely in fog.
Tiny water droplets hanging in
the air create cloud at ground
level. This is called fog and it is
a form of water vapour. Thick
fog can make it hard to see
into the distance.

Wind

Wind is caused by warm air
rising and cold air rushing in
to take its place.

25

Dpalnagenroeuts Tsunamis

The top, rocky layer of the Earth Earthquakes happen underwater,
is made up of gigantic plates that too. When they occur, it can cause
float on a layer of hot rock. Where water levels to rise and create
these plates meet, earthquakes and gigantic waves called tsunamis.
volcanoes are common. They travel at great speeds and
can cause a lot of destruction.

Seismographs Earthquake strength is
record the measured using the Richter
movement of scale. Over eight on the scale
the Earth. is a very strong earthquake!

The point on the ground In places where earthquakes are
directly above the red dot is common, buildings are designed
the epicentre. This is where to wobble but not collapse.

the most damage occurs.

Earthquakes The red dot is called
the hypocentre.
When plates collide or This is where an
scrape against each other, earthquake begins.
pressure builds up. After
this pressure is released,
shock waves travel through
the ground. This is known as
an earthquake and it can be
very dangerous.

26

Volcanoes When magma
flows out of a
Volcanoes are openings in the volcano it is
ground where hot, melted rock, called lava.
called magma, escapes from deep
underground. It’s best not to be A thermometer measures
near a volcano when it’s erupting! lava temperature, which
gets as hot as 700-1,300°C
Scientists take measurements
of changes in the volcano’s (1,300-2,400°F )!
shape, vibrations, and gases to Lava can ooze
try to predict when the next from cracks in
the sides of
eruption might be. a volcano.

A magma chamber The main vent
is a pool of hot, is the biggest
melted rock. opening for
magma to escape.

27

Fish Reptiles Cold-blooded
Fish live in water, breathe Reptiles have scaly skin animals sunbathe
in oxygen using gills, and are and are cold-blooded. Most to warm up
cold-blooded. They have fins lay eggs. Apart from snakes, their bodies.
almost all other types of
to help them swim. reptile have four legs.

Pandas spend
16 hours each day
eating bamboo.

Birds Amphibians
Birds have feathers, wings, Amphibians, such as frogs
and a hollow skeleton. Most can and newts, live in water and
fly, but some, such as penguins, on land. They are cold-blooded
cannot. Birds lay eggs and
and have moist skin.
are warm-blooded.

Mammals Vertebrates
Mammals have hair and
are warm-blooded. They give These animals have a
birth to live babies, which they backbone and a skull. A strong
feed with milk. You are skeleton inside their bodies lets

a mammal! them grow larger than
invertebrates.
Animals
There are millions of different types of animal
in the world. Scientists divide them into two Less than 5% of all the
groups – vertebrates and invertebrates. different types of animal
However, all animals have things in common, are vertebrates. There are
such as breathing air, moving around to many, many more types
find food, and sensing the world.
of invertebrate.
28

If a starfish loses one
of its arms, it can grow
a new one to replace it!

Crustaceans Echinoderms
Most crustaceans, such as These spiny-skinned animals do
crabs, lobsters, and shrimps, not have brains! They include
live in or around water. They
starfish and sea urchins, and
have hard shells. live on the ocean floor.

Arachnids Molluscs
Spiders, ticks, mites, scorpions, Molluscs have soft bodies. Many,
including snails and clams, have
and daddy longlegs are all hard shells. Most live in water –
types of arachnid. They all
for example octopuses – but
have eight legs. those living on land must

keep damp.

Invertebrates Insects
Insects have six legs, two
These animals don’t have a antennae, or feelers, on their
backbone, or spine. Some, such head, an exoskeleton, and many
as slugs, are soft and squishy. can fly. There are more than
one million known types
Others, such as insects, have
an exoskeleton, which is a of insect.
kind of shell.
Small and tall

Animals come in all shapes and
sizes. Some are so small you need a
microscope to see them. Bumblebee
bats are the smallest mammals,
while giraffes are the tallest
animals in the world!

Octopuses are the Paper clip Bumblebee bat Adult man Giraffe
cleverest invertebrates. 3.2 cm (1.2 in) 4 cm (1.57 in) 1.7 m (5.8 ft) 6 m (20 ft)
It’s been found that they
can solve problems to

get food.

29

Plants Plants get their
energy from sunlight.
From daisies to palm trees, there are
thousands of different types of plant Farming
in the world. They provide us with
oxygen to breathe, many kinds of food, Farmers grow crops, such as corn,
and wood to make homes and furniture. wheat, fruit, vegetables, and cotton.
They give their crops fertilizers,
which are extra nutrients, to make
them grow bigger and faster.

Leaves Engineers and scientists
A plant’s leaves absorb sunlight, change crops to improve
which is used to make food for them – for example, so
the plant. The leaves also they don’t get diseases.
release oxygen into the air.
Stamens
Plant parts These parts of the
flower make a fine
Many plants are made powder called pollen.
up of similar parts. They
have roots in the soil, Stigma Some plants have
strong stems, leaves This part of the flowers, some lose their
growing from the stems, flower has a skicky leaves in the winter, and
and sometimes flowers. end. It collects pollen some even eat insects!
to make seeds.
Roots
The roots anchor Stem
the plant and absorb The stem supports the
water and nutrients plant, and both water and
from the soil. food travel along it. We get
wood from tree stems.
30

Machinery lets farmers Apples, nuts, tomatoes,
plough, sow, or harvest huge grapes, cucumbers,
and pumpkins are all
fields of crops quickly. types of fruit.

Butterflies can Fruit
carry pollen
long distances. Fruit have seeds inside them.
When animals eat fruit, the
seeds come out in their poo.
This way, the seeds are
carried to new areas, where
they grow into new plants.

Insects Fungi

Insects spread pollen between flowers Mushrooms and toadstools are not
so that they can make seeds. Many plants. They belong to a kingdom of
flowers attract insects with a sweet living things called fungi. They feed
liquid called nectar. When they come on living or dead plants and animals
to drink it, the pollen sticks to them. and soak up their nutrients.

Bees are the
most important
pollen carriers.

Mushroom

31

Evolution

Over time, animals and plants change, or
adapt, so they can survive in their environment
for longer and have more babies. This is
called evolution. Evolution isn’t a quick
process – it takes millions of years!

55 million Whale evolution
years ago
Pakicetus Incredibly, the ancestors of whales
Pakicetus lived on land, possibly lived on land! Over time, they grew
near water. It had four hoofed bigger and bigger and moved to
feet and sharp teeth for chewing different places, including the ocean.
flesh or plants.
Natural selection means The powerful
that some living things long tail helped
are better at surviving to steer in water.
than others.
50 million
32 years ago

Ambulocetus Short legs and
Ambulocetus evolved from padded feet were
pakicetus. It lived in water perfect for paddling
and hunted like a crocodile. in water.

Darwin Wide tail

Charles Darwin was a scientist
who studied how animals and
plants changed over time. He
came up with the theory of
evolution to explain what he saw.

Bowhead whale
By the time the bowhead whale evolved,
it had grown enormously in size, with

an appetite to match. They feed
on a massive 100,000 kg
(220,000 lb) of
plankton a year!

Today Bowhead whales can
survive for more
Giant flippers than 100 years!

Palaeontologists are scientists Breeding
who study fossils – the remains
of ancient animals and plants. It’s hard to imagine that a
chihuahua evolved from a
Long, pointed wolf, but it did! Humans breed
snout dogs for herding, security,
Much smaller legs companionship, and even for
than ambulocetus their appearance.

38 million Wolf Chihuahua
years ago
Dorudon
Twelve million years later,
the front feet had evolved
into flippers and had
become webbed.

33

TfoheoAdrctwic eb Arctic tern

Animals need food to give them the These seabirds catch fish by
energy they need to move and think. A diving into the water at great
food web shows what different animals speeds. Adults are safe from
in a particular place, or habitat, eat – predators, but their eggs and
and how they all link together. chicks are not.

Polar bears have white
fur so that they blend
into their surroundings.

Polar bear

Polar bears are apex
predators, which means
they eat other animals,
such as ringed seals, but
no animals eat them.

The killer whale
is also known
as an orca.

Killer whale

Killer whales hunt in
the ocean and also grab
unsuspecting seals near
the water’s edge. They
are apex predators, too.

34

Plant plankton Some plankton are so
rely on the Sun small they can’t be seen
for energy.
with the naked eye.
Arctic cod

These fish are a food source
for many marine animals.
Arctic cod eat plankton,
shrimp, marine worms, and
sometimes even each other!

Ringed seal Plankton

This meat-eating animal Tiny drifting animals and
eats fish, shrimp, and plants called plankton are
plankton, but is hunted eaten by Arctic cod and
and eaten by polar coldwater shrimp.
bears and killer whales.
Draw your own

To draw your own food web, start
by choosing a habitat, such as a
forest or a desert. Now think about
what the animals in that habitat eat
and show how they link together.

Coldwater shrimp

Coldwater shrimp live near
the ocean floor and mostly
eat plankton. They make a
tasty snack for seals.

35

Ecosystems
Plants and animals live and interact
with each other and their surroundings The biggest coral reef
in communities called ecosystems. is the Great Barrier
Ecosystems can be as small as a tree Reef off the coast of
trunk or as large as a rainforest.
eastern Australia.

Coyotes survive American desert The great horned owl
in many different makes its nests on saguaro
places because The deserts of southwest USA cactuses, where its eggs
they will eat are extremely hot but lots of will be safe from predators.
whatever is animals and plants live there. The sharp spines
available! Animals avoid the heat of the will put off any
day by hunting at night, and egg thieves!
plants can survive a long time
without any rain.

The organ pipe
cactus opens its
flowers at night.

This rattlesnake will shake
the rattle on the end of its
tail if it feels threatened.

The saguaro
cactus is the
largest cactus
in the USA.

36

Under the sea Reefs are home to The banded sea
all sorts of fish. krait is a type of
Coral reefs are amazing underwater sea snake.
structures formed by living creatures.
They grow in warm, shallow waters in This type of coral is
tropical regions and are home to a called table coral.
dazzling variety of life.

A stinging ...while clownfish
anemone provides scare off fish who
a safe haven for want to eat the
clownfish... anemone!

Mountains Golden eagles have incredible
eyesight for spotting prey
from great distances.

The Himalayan mountain range
in Asia is a tough place to live.
Animals and plants have to
cope with extreme cold, storms,
and living at great heights.

Snow leopards are Pikas are hunted
incredibly rare. They eat by golden eagles.
wild sheep and goats.
Wild goats, like this Mount Everest in the
markhor, munch Himalayas is the world’s
plants and spread highest mountain.
seeds in their dung.

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Irnasiidne aforest Emergent layer

Tropical rainforests are made up The tallest trees can reach
of four different layers. Each one heights of up to 55 m (180 ft).
provides a home for different That’s a long way up!
types of animals and plants.

Canopy Tree frogs
rarely leave
The canopy is a thick layer the canopy.
of treetops that is home to
animals, birds, and lots of Sloths move
climbing plants. very slowly.

Understorey Pitcher plant

Short trees and
shrubs provide cover
for small animals as
well as predators
such as jaguars.

Forest floorOkapi

This is the darkest part of the
rainforest. It’s muddy and
covered in leaves that have
fallen from the trees above.

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Scarlet macaw Sunlight in layers
Blue morpho
butterflies are Each layer of the rainforest gets
found in the different amounts of sunlight.
emergent layer.
Emergent layer
Gibbons are Full sunlight
a type of ape Canopy
from Asia. Lots of sunlight
Understorey
Sunlight and shade
Forest floor
Mostly shade

The toucan’s beak is so Toucans use
colourful. Why not try to their beaks
to grab fruit
paint a picture of it? and nuts.

Snakes slither
between the
layers.

Chameleons can Jaguar
make their skin
change colour!

This gigantic An teater
flower stinks
of rotting flesh Leafcutter ants
to attract flies
that will spread
its pollen.

39

cClhimaatne ge

Climate is the general weather conditions over
a large area. It changes naturally over long
periods of time. However, recently Earth’s climate
has been getting warmer faster than usual.

Polluted planet

Fossil fuels, such as oil and coal, are the buried
remains of ancient plants and other living things.
Burning them releases harmful gases, especially
carbon dainodxidpeol(lCutOe 2o),uirnptolatnheet.air. These gases
heat up

Carbon dioxide is called a Factories
“greenhouse gas” as it traps the Over the last few
Sun’s energy in our atmosphere, hundred years, many
coal-burning factories
heating the planet. were built. They pumped
more CO2 into the
atmosphere.

Motor vehicles
Cars and lorries use diesel and
petrol as fuel. These fuels are
made from oil. Burning them
releases CO2 into the air.

Chopping down forests
Trees soak up CO2 like a big sponge. By
chopping down forests for timber or to
make farmland, we take away one of the
best ways to remove CO2 from the air.

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A greener future Experts predict that by
2040, one-third of all cars
Scientists and engineers now look for ways to bought will be electric cars.
make energy that do not burn fossil fuels. They
are especially interested in energy sources that Electric cars
won’t ever run out, such as wind and sunlight. These cars run on rechargeable batteries,
rather than petrol. Because of this, they
Solar panels don’t pollute the air with CO2 and other
Solar panels absorb harmful gases.

sunlight to make Effects of
electricity and heat. climate change

Trees A warmer climate can lead to extreme
Planting trees helps to fight weather. Big storms are becoming
climate change because plants more common, often causing flooding.
absorb CO2 from the air. They Climate change is also melting the sea
use the carbon to make their ice covering the Arctic Ocean.
own food and grow.

Every tree makes a
difference. This little one
could live for 200 years!

Flooding

Wind farms Melting Arctic sea ice
Wind turbines make
electricity from wind
power rather than by
burning fossil fuels.
Groups of turbines
are called wind farms.

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Microlife Dust mites

There are billions of very tiny living These blobby creatures eat bits
things around us, on us, and even of dead skin found in house
inside us! Our eyes can just about dust and mould. They’re very
see some of this microlife. However, hard to see because they’re tiny
we need to use a microscope to see and almost see-through.
how amazing they really are.
Dust mites have
Hair lice Hair lice have two many little hairs,
antennae, or feelers, called setae.
These tiny insects live in hair, on their heads.
usually children’s. They bite
the scalp to feed on blood.
However, apart from
causing itching, they
are not harmful.

Hair lice glue their Tardigrades have four
eggs, called nits, pairs of chunky legs with
to shafts of hair. tiny claws. Their name
means “slow stepper”.
Tardigrades

Also called water bears, these
little animals live in wet places,
such as mud. They are super
tough, can survive in space,
and can go without food and
water for more than 30 years!
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Plankton

Plankton are living things that drift
about in oceans, rivers, and lakes.
Some are microscopic, or really
tiny, but others, such as jellyfish,
are much bigger. Many sea and
freshwater animals eat plankton.

Bacteria

Bacteria are microscopic living things, made
of just one cell each. They are much smaller
than the cells that make up our bodies. In
fact, our bodies contain billions of bacteria!
Some of these bacteria are useful,
supplying us with important nutrients.
However, others can cause nasty diseases.

This bacterium has
started to split into
two new cells.

Viruses

Viruses are tiny things
that can make people,
animals, and plants ill.
They enter cells and then
make copies of themselves.
Flu, colds, and measles are
all caused by viruses.

43

Tbhoe dhuyman Large intestineBrain Our supercomputer,
the brain, controls our
An adult human body44 thoughts and actions.
contains 206 bones, 650
muscles, and trillions of tiny The human body is made up
building blocks called cells. of systems. The nervous system
Each part of the body has controls how we think, feel, and
a different job to do, but move, the immune system fights
they all work together sickness, and the digestive system
to keep the body
running smoothly. turns food into energy.

Lungs Organs

Lungs transport Heart Our body is made up of lots of
oxygen from the different organs. The organs that
air into our help us digest food include the
bloodstream. stomach, the liver, the intestines,
and the kidneys. Even our skin
X-rays are Kidneys Liver is an organ!
not just used to ach Stom
look at bones, they The heart pumps blood
also scan luggage inStemsatilnl e around our body.

at airports. The liver has more than
500 jobs. We wouldn’t be
able to survive for more
than two days without it!

X-rays allow us Muscles
to see what our
bones look like. Muscles are the stretchy cords
connected to our bones that
Bones allow us to move. Some muscles
work without us having to think
Newborn babies have more than 300 about them, while others are
bones. By the time we reach adulthood, controlled by our brain.
some bones have joined together to
make 206 in total. They fit together to Skin
form the skeleton, protecting our inner
organs and keeping us upright. Skin is the waterproof outer layer
that stops us from injuring or infecting
Blood Veins and arteries our insides. It is the biggest organ
are blood vessels in the human body, making up
that carry blood to 15% of our weight!
and from the heart.

45 The heart pumps blood around
our body through tubes called
blood vessels. Blood transports
oxygen to parts of the body
and fights germs.

Two sides The front part of the This part of the brain is
brain is all about your in charge of how we move
The brain has two sides. personality – how you our bodies. It can tell us
The left side controls the behave, and what you to walk, run, or dance!
right side of our body, like and don’t like.
while the right side is in
charge of the left side of Planning
the body! movements
The more wrinkly
Left Right Thinking and your brain, the Movement
personality smarter you are!

? Speech

Hearing

This part of our
brain allows us to
speak to each other.

Think You figure out what Memory
different sounds This part of your brain is
about it are in this part of where you keep all of your
the brain. memories, like the first
time you rode a bike or
Your brain may look like a big wobbly your last birthday party.
ball of jelly, but it works like an amazing
supercomputer. It sits in your head and
allows you to see, hear, talk, move, feel,
think, imagine, and remember.

46

Every time you touch Artificial intelligence
something a message goes
to this part of the brain. Computers can be taught to think and
make decisions like humans. This is
Being able to understand our called artificial intelligence (AI). Mobile
surroundings helps us to make phones use AI to help answer any
good decisions about how to questions you might have or tell you
move around. what’s in your diary.

Touch What’s the weather
like today?
Understanding
emotions, like
happiness or sadness,
helps us to respond
well to other people.

Awareness
of space

It’s raining. Take
an umbrella!

Emotional Making
understanding images

Seeing Our brain receives
information from our
eyes and makes sense
of what we’re seeing.

Coordination Nervous system
This bit of the brain helps
us to move smoothly. It’s We have a huge network of
useful for things such as nerves inside us, which link the
walking and writing. brain and the spinal cord to
the other parts of the body.
The spinal cord carries messages
to and from the brain.

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The senses Sight
A lens inside each of
Our senses let us understand the world our eyes focuses light
around us. They tell us what’s safe and what’s onto the back of the
dangerous, and let us see and hear each eye. There, receptors
other. Special receptors in our bodies help sense brightness
us to sense our world. and colours.

The main senses

Sight, smell, touch, taste, and
hearing are our five main
senses. However, we also
have other senses that
help us survive.

Smell
Tiny receptors inside
the nose pick up many
different odours. Smell
is closely linked to the
sense of taste.

Touch Taste
The skin contains Taste buds on the top of the
many receptors tongue sense five different
that react when flavours. These are salty, sweet,
we touch things. sour, bitter, and a savoury
flavour called umami.
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