Scope and Sequence
Science,
Engineering,
and Technology
Units
Lessons
Lesson 1: What is a machine?
Unit 1: Technology and the Design Process
EB
TH IG
How can technology affect our lives?
Lesson 2: What is the design process?
Unit 2: Plants
EB
TH IG
How do plants change and grow?
Unit 3: Living Things
Life Science
EB
TH IG
How do living things
grow and change?
Lesson 1: How do plants use roots and stems to grow?
Lesson 2: How do plants use flowers and cones
to reproduce?
Lesson 1: What are the life cycles of some animals?
Lesson 2: How can you classify animals?
Lesson 1: What is an ecosystem?
Unit 4: Ecosystems
EB
TH IG
How do living things interact?
Lesson 2: How do living things get energy?
Lesson 3: How do ecosystems change?
Unit 5: Body and Illness
Lesson 1: What causes different diseases?
EB
TH IG
How can I keep my body healthy?
Lesson 2: How can you avoid getting diseases?
Lesson 1: What is the water cycle?
Earth Science
Unit 6: Earth and Weather
EB
TH IG
How do forces cause
changes on Earth’s surface?
Lesson 3: What are weathering and erosion?
Unit 7: Earth and Our Universe
EB
TH IG
Lesson 1: What are Earth’s patterns?
How do objects in space
affect one another?
Physical Science
Lesson 2: How do we describe features
of Earth’s surface?
Unit 8: Energy and Its Forms
Lesson 2: What is known about the moon?
Lesson 1: What are some forms of energy?
EB
TH IG
How can energy change?
Lesson 2: What are heat and light energy?
Lesson 1: What is motion?
Unit 9: Forces and Motion
EB
TH IG
What forces cause motion?
Lesson 2: How does force affect motion?
Lesson 3: What is gravity?
x
Scope and Sequence
I will learn...
Key Words
• about simple and complex machines.
• work, wheel and axle, wedge, lever, inclined plane,
pulley, screw
• the steps of the design process.
• design process, engineer, research, prototype
• how plants use roots and stems to grow.
• roots, stems, ground, leaves, nutrient, cactus
• how some plants use flowers and cones to
reproduce.
• reproduce, pollen, pollinate, germinate, cones, life cycle
• the life cycles of different animals.
• larva, pupa, metamorphosis, amphibian, gills, lungs
• how to classify animals.
• trait, vertebrate, scales, cold-blooded, warm-blooded,
invertebrate, arthropod
• what an ecosystem is.
• ecosystem, habitat, population, community
• how living things get energy.
• producer, consumer, decomposer, food chain, herbivore,
carnivore, omnivore
• how ecosystems change.
• resources, drought, adaptation
• what causes some diseases.
• infectious disease, microorganism, noninfectious disease,
abnormal, pathogen, toxin, immune system, allergen
• how to avoid getting some diseases.
• Salmonella, antibiotic, vaccine, antibodies, symptoms, chronic
• about the water cycle.
• water cycle, evaporation, condensation, precipitation
• features and changes on Earth’s surface.
• landform, landslide, volcano, lava, earthquake, faults
• about weathering and erosion.
• weathering, erosion, mudflow, rockslide
• what causes daytime, nighttime, and the seasons.
• axis, rotation, revolution, seasons, shadow
• what causes the phases of the moon.
• moon phase, telescope, crater, new moon, full moon
• about different forms of energy.
• energy, electrical energy, mechanical energy, sound energy,
potential energy, kinetic energy
• what heat and energy are.
• matter, particles, thermal energy, spacecraft, solar panel,
generator
• what motion is.
• position, motion, speed
• how force affects motion.
• force, friction, magnetism, iron, magnet, steel
• what gravity is.
• gravity, weight, matter, mass
Scope and Sequence
xi
Unit
1
Technology and the
Design Process
How can technology
affect our lives?
I will learn
about simple and
complex machines.
ō the steps of the design
process.
ō
1
Look and label.
can opener
seesaw
2
3
4
axe
wheel
scissors
screw
What are each of the machines
used for? Discuss with a partner.
How can machines help you solve
problems? Discuss as a class.
Unit 1
T hi nk !
How will this tiny
robot help people
in the future?
Key Words
Lesson 1 . What is a machine?
1
Read and complete the graphic organizer.
Write details about work.
Work
Is kicking a soccer ball work? To a scientist it is. In
science, work means the use of a force to move an
object across a distance. You do work when you rake
leaves, pedal a bike, or kick a soccer ball.
work
ō wheel and axle
ō wedge
ō lever
ō inclined plane
ō pulley
ō screw
ō
It may be hard to solve a math problem. But it is not work.
You may push hard to move a large rock. But it is not work
if the rock does not move. You only do work when you move
an object. The amount of work you do depends on how much
force you use and how far you move the object.
Main Idea
Detail
Detail
Detail
Let’s Explore! Lab
Unit 1 5
A wheel and axle is made of
a round object, a wheel, attached
to a post, called an axle. Turning
the wheel causes the axle to turn.
The axle turns a small distance as
the wheel turns a greater distance.
3
Read and write the names of the six
machines shown on pages 6 and 7.
Simple Machines
Do you recognize any of the objects in the
pictures? They are all simple machines. Simple
machines have just one or two parts. These
machines do not lessen the amount of work you
do, but they help make work easier. Six kinds of
simple machines help you do work.
A wedge is a simple machine made from
two slanted sides that end in a sharp edge.
As a wedge is pushed through material such
as wood or food, it cuts or splits the material.
A lever is a stiff bar that rests
on a support. A lever is used
to lift and move things. When
you push down on one end,
the other end lifts up.
6
Unit 1
I Will Know...
5
Look at this shape . Draw an on the
simple machine that has this shape. How
does the shape help this machine work?
Discuss with a partner.
6
Which simple machine would you use for
each task below? Discuss with a partner.
A screw is an inclined plane
wrapped around a center post.
Screws can be used to hold
things together and to raise
and lower things.
A. Raise a flag on a pole.
B. Open a can of paint.
C. Cut an apple.
7
How is a jar lid a screw? Discuss as
a class.
An inclined plane, or a ramp,
is a slanted surface. It connects a
lower level to a higher level. Less
force is needed to move an object
over a longer distance.
A pulley can make work
easier in two ways. It can
decrease the amount of force
needed to move an object. It
can also change the direction
that the force is applied.
Unit 1 7
8
Read and look at the machines on pages 6 and 7.
Complete the captions with words from the box.
Complex Machines
Simple machines are often put together to do
bigger jobs. These complex machines are made
up of simple machines that work together.
The can opener below is a complex machine. Find
the simple machines that it is made of. These simple
machines work together to grip, turn, and slice
through a can lid.
wedge
9
axle
levers
Complex Machines
Search your home for
one complex machine.
Draw and label the
complex machine.
Identify each simple
machine in the complex
machine.
The sharp edge
that cuts the top
of the can is a
.
Write a list of three complex
machines that you and your
family have used this week.
With a partner, compare your lists.
1. Possible answers :
2. bicycle, can opener,
3. stapler, scissors
The winding handle
is an
T hi nk !
that turns the gears.
How do you know
when a complex
machine is at work?
The handles
are made of
.
8
Unit 1
10
Read. Where would you find a wedge inside a lawn mower? Discuss with
a partner and write your answer.
Lawn Mowers
Engineers design and develop large
and small machines. These machines are
made of simple and complex machines.
A simple machine can be a lever, wheel
and axle, pulley, wedge, inclined plane,
or screw.
Simple machines are often put together to make a complex machine, such as a
lawn mower. It is made of different parts. Some of these parts are simple machines,
such as a wheel and axle. A wheel and axle is used in a lawn mower to help it
move. A screw is another simple machine. Screws are used to hold the lawn mower
pieces together. Lawn mowers have wedges that end in sharp edges. Where would
you find a wedge inside a lawn mower?
Bicycles
The bicycle is a complex machine, too. What simple machines make it up? How
does each simple machine help make the bicycle work?
11
Draw a line from each simple machine to its correct part on the bicycle.
A. lever
B. pulley
C. wheel and axle
Lesson 1 Check
Got it?
60-Second Video
Unit 1 9
Lesson 2 . What is the design process?
1
Look at the pictures. How are the two computers
similar? How are they different? Discuss with
a partner.
Design Process
When people design something new,
they follow the steps of the design
process. The design process is
a step-by-step method used to solve
a problem.
People use the design process
to find a solution. A solution is an
answer to a problem. The design
process allows engineers to
produce and test possible solutions.
An engineer is any person who
designs new technologies.
2
10
Why is it important for engineers to
follow the steps of the design process?
Discuss as a class and write the answer.
Unit 1
Let’s Explore! Lab
Key Words
design process
ō engineer
ō research
ō prototype
ō
Saved Solution
Save some items
instead of throwing
them away. Think of
a simple problem.
Use the items to build
something to solve your
problem. Test what you
build to see if it works.
Evaluate your solution.
Share your results with
someone in your class.
T hi nk !
Why do engineers
sometimes research
problems in different
ways?
3
Read and complete the information related to Kramer’s 1. Problem:
invention. Check your answers with a partner.
Identify the Problem
Engineers identify the problem during the first step
of the design process. Before producing a design,
engineers consider if there is a need for it. In 1979,
there were only large music players that needed tapes
or records to play music. British inventor Kane Kramer
identified this as a problem. Kramer wanted to design a
smaller music player that did not need tapes or records.
His idea led to the invention of the digital audio player.
2. Research:
a.
b.
Do Research
The next step is to research the problem. Research
means to look for facts about something. People can
research problems in different ways. Some engineers
research by talking to other people and reading articles.
Kramer researched ways to make a digital audio player.
Kramer took notes about what he learned.
Unit 1 11
car prototype
T hi nk !
How can this car
prototype help
engineers?
Someone may test an
inner part of a computer
to see how well it works.
prototype worked.
12
Unit 1
I Will Know...
6
Read and answer the questions.
Communicate Results
Engineers communicate results about their tests to
people working with them. Engineers may share how they
designed and built the prototype. They also explain how
the experiment was carried out. After testing it, Kramer sent
a report of his invention to a group of people. He hoped
the people would invest money in his invention. The report
described the way his invention worked. It also explained
how the player could change the way people listened to music.
1. How did Kramer communicate his results? .
2. What did the report say?
Evaluate and Redesign
The final step is to evaluate and redesign the prototype.
Evaluate means to find out how well something works. People
try to make a prototype better by redesigning it. When people
heard about Kramer’s idea of the digital audio player, they
designed their own versions. The first digital audio player
became available to the public in 1997. It could play about
one hour of music. Newer digital audio players can hold
enough music to play for more than 100 days!
7
Look at the photos. How are these
audio players different? Discuss
with a partner.
Lesson 2 Check
Got it?
60-Second Video
Unit 1 13
Let’s Investigate!
Materials
What makes a bridge strong?
ruler
4 books
1.
Place two stacks of books 25 centimeters apart.
2.
Make a model of a bridge between the books.
Use stir sticks, tape, and a note card.
Brainstorm potential solutions.
3.
Place the cup on the bridge.
10 craft sticks
10 stir sticks
note card
tape
coins
plastic cup
4.
Predict how many coins the bridge will hold. Record your prediction.
5.
Put coins in the cup one at a time. Record how many coins the bridge holds
before it falls.
6.
Repeat Steps 2 to 5. Use craft sticks this time.
Model
Number of Coins
Prediction
Stir sticks
Craft sticks
14
Unit 1
Let’s Investigate! Lab
Result
Unit 1
How can technology
affect our lives?
Review
Lesson 1
What is a machine?
1
The nail clippers are a complex machine made up
of two simple machines. Label each simple machine.
Lesson 2
What is the design process?
2
The first working product that uses a design
is called a
.
a. method
b. technology
c. redesign
prototype
3
d.
After you test a prototype, you communicate information to
other people. This information is called
.
a. a hypothesis
b. the results
c. a story
d. an investigation
Got it? Quiz
Got it? Self Assessment
Unit 1 15
Unit
2
1
Plants
How do plants
change and grow?
Look and label.
pollination
stem
cactus
pine cone
roots
seeds
2
With a partner, say three other
plant parts.
3
What do plants need to grow?
Discuss as a class.
16
Unit 2
T hi nk !
How can cypress
trees live and
grow in water?
I will learn
how plants use roots
and stems to grow.
ō how some plants use
flowers and cones to
reproduce.
ō
Lesson 1 . How do plants use roots and stems to grow?
1
Key Words
Read and label the parts of the tree.
roots
ō stems
ō ground
How Roots Help Plants
Look at all the roots of the fir tree in the
picture. Plants need roots and stems to take
in and move materials plants need to live
and grow.
The root system of a plant is often below
the ground. You usually cannot see it. Roots
keep the plant stable in the ground. Roots
store food made by the plant’s leaves.
Roots also take in water and materials
called minerals from the soil. The plant gets
nutrients from the water and minerals. A
nutrient is any material needed by living
things for energy, growth, and repair. Plants
need nutrients to live and grow.
2
ō
leaves
ō nutrient
ō cactus
ō
1.
2.
3.
Write three ways that roots help plants.
1. They keep
.
2. They store
.
3. They take
.
3
Circle, in different
colors, the roots,
stems, and leaves of
the mangrove trees.
Let’s Explore! Lab
Unit 2 17
4
Read and write the names of the two types of roots.
Types of Roots
Many plants have one large root called a taproot.
Carrots are examples of taproots. Taproots grow deep
into the soil toward Earth’s center due to gravity.
Taproots take in water and nutrients from the soil.
The roots also store food made by the plant.
In some plants, such as grass and pine
trees, roots spread out in many directions.
This type of root is called a fibrous root.
Fibrous roots of the same plant are all
about the same size. They grow longer
than taproots. Fibrous roots also grow close
to the surface to take in water after it rains.
How Stems Help Plants
Stems support the leaves, flowers, and fruits of plants.
Stems often grow up toward the light, plants’ main source
of energy. Most plant stems have tiny tubes that move
water and minerals from the roots to the leaves. Other
tubes move food from the leaves to the stems and roots.
root hair
Types of roots:
1.
2.
pumpkin stem
Some stems are thin and grow along the surface of
the ground. The stem of a pumpkin can grow roots and a
new plant. Other stems, called vines, grow parts that wrap
around objects that support the plant.
5
Read and circle T (true) or F (false). With a partner, correct the false statements.
1. Stems support the roots of plants.
T / F
2. Roots move water to the leaves.
T / F
3. Pumpkin stems grow under the ground.
T / F
18
Unit 2
I Will Know...
6
Read and match
the columns.
Types of Stems
Plant stems come in
many different shapes,
sizes, and colors.
Some stems grow
below ground. Other
stems, such as these
cactus stems, grow
above ground. Notice
how thick cactus stems
can grow. Cactus stems
swell up to store water.
Cactus stems are thick
and waxy. This keeps
them from losing water.
Cactus stems help them
survive in a desert.
Parts of some stems grow below ground. When you eat a potato, you eat the part of
the stem that stored food below ground. Stems that grow below ground can make new
stems from buds, like the potato’s “eyes.” These buds grow up out of the ground and
become new plants.
a) Cactuses and potatoes
become new plants.
b) Cactus stems
grow below the ground.
c) Potatoes
have different types of stems.
d) Potato’s “eyes”
grow above the ground.
7
With a partner, research three more examples of underground stems.
Lesson 1 Check
Got it?
60-Second Video
Unit 2 19
Lesson 2 . How do plants use flowers and cones to reproduce?
1
Read. Which is the best summary for the paragraph?
Discuss with a partner.
Reproduction
Most plants make seeds that grow into new plants.
Some plants grow stems or roots that grow into new
plants. Plants can reproduce in all these ways. When
plants reproduce, they make more of the same kind.
For example, maple trees produce
seeds. These seeds can grow into
new maple trees.
Key Words
reproduce
ō pollen
ō pollinate
ō germinate
ō cones
ō life cycle
ō
seeds with parachutes
Each seed carries information from
the parent plants. The seed uses this
information and food stored from the
parent plant in the seed to grow into
a new plant. The new plant will
be like its parents. After seeds are
produced, they may scatter or move
away from the parent plant. This gives
the new plant more room to grow.
a) Only seeds can make new plants.
b) Only stems and roots can make
new plants.
c) Seeds, stems, and roots can grow
into new plants.
2
20
Each seed in the picture above has a tiny parachute. How do these parachutes
help the seeds scatter? Discuss as a class and write your answer.
Unit 2
Let’s Explore! Lab
3
Read and underline two sentences in the text that describe the picture below.
Parts of a Flower
Flowering plants grow flowers that make seeds. Flowers have different parts. One
part makes pollen. Another part, the petals, attracts bees and other animals to the
flower. Animals or wind can pollinate, or carry pollen to, another flower. Pollination
happens when wind or animals move pollen to the part of the flower that makes
seeds. After pollination, seeds form near the center of the flower. Another part, fruit,
often grows around the seed to protect it. A peach is an example of a fruit.
4
Read and complete the captions with words from the box.
pollen
seeds
petals
bees
I Will Know...
Unit 2 21
5
Read and label the parts of the seed.
How Seeds Grow
Seeds have different shapes, sizes, and colors. All
seeds have the same parts. Every seed has material inside
it that can grow into a new plant. The seed is covered by
a seed coat. The seed coat protects this material. Many
seeds have one seed leaf or two seed leaves. As the tiny
plant grows, it uses food from the seed leaves.
Seeds need air, the right amount of water, and the right
temperature to germinate, or begin to grow. With the
right conditions, the young plant, or seedling, germinates.
As the seedling grows, it grows out of the soil.
Leaves grow from the stem. The leaves use sunlight
to make sugar. The plant uses the sugar for food. The
seedling can grow into an adult plant that has flowers.
The flowers are pollinated, and new seeds form. If
these new seeds germinate, they can grow into new
plants. Then the cycle begins again.
seed leaf
seed coat
developing plant leaf
Food and Energy
Energy and resources
are needed to grow
food. The food must be
moved from the farm
to the store. This also
uses energy. Think of
ways you can avoid
wasting food. Make a
list. Share your list with
your classmates.
seed germinating
seed
T hi nk !
Why does a seed
need a seed coat?
22
Unit 2
6
Read and number the stages (1–3) in order. Then check
your answers with a partner.
How Cones Help Plants
Cones are made by conifer plants. Conifer plants
grow cones instead of flowers to make seeds. Conifers
make two types of cones. One cone is a small pollen
cone. The other cone is a large seed cone. Wind
blows pollen from small pollen cones to large seed
cones. When pollen sticks to the large seed cones, seeds
begin to grow inside. A seed grows under each scale of the
conifer forest
seed cone. When the seeds are fully developed, they float to the
ground. If conditions are right, each seed can grow into a new plant.
2
3
1
Unit 2 23
7
Read and label the stages in the life cycle of a flowering plant.
Plant Life Cycles
Living things change during their lives. Most living things begin their lives small and
then grow larger. They may develop certain features as they change into adults. They
reproduce to make more living things of the same kind. Eventually, living things die. The
stages through which a living thing passes during its life are called a life cycle.
Life Cycle of a Flowering Plant
A pumpkin plant is a kind of flowering plant. The life cycle of a pumpkin plant has
several stages, as shown in the diagram.
Pollination
Adult Plant
Seed
1
Growth
2
4
3
24
Unit 2
8
Read and compare the two life cycles shown on these two pages.
Write titles for stages 2 and 3.
Life Cycle of a Conifer Plant
Pine trees are a type of conifer. Conifer plants grow cones instead of flowers to make seeds.
1
2
4
3
9
Life Cycle Length
Some plants live for only a short time.
For example, many desert plants grow,
flower, and make seeds over a period
of a few weeks.
Many trees can live longer than
humans do. The chart to the right shows
the average life cycle length of some
of these trees.
Lesson 2 Check
Read the table. With a partner, name
the trees in order from the shortest
life cycle to the longest.
Type of Tree
Average Length
of Life Cycle
American elm
175 to 200 years
Bristlecone pine
3,000 years
Douglas fir
300 years
Redwood
500 years
Got it?
60-Second Video
Unit 2 25
Let’s Investigate!
Materials
How does water move through celery?
stalk of
celery
scissors
hand lens
water with blue
food coloring
1.
Cut a thin slice from the end of a celery stalk.
Observe it with a hand lens or microscope.
In the chart, draw what you see.
2.
Put the stalk into the water with blue food
coloring. Wait 24 hours.
3.
Cut 2 cm off the stalk’s end.
Then cut a thin slice from the
new end. Observe it with a
hand lens or microscope.
Draw what you see.
4.
Observe the whole stalk.
Draw what you see.
5.
Compare the slices. How
are they different?
metric ruler
microscope
(optional)
6.
During this investigation what happened
to the celery stalk in the blue water?
7.
Which parts of plants move water to
the leaves?
Observations of Celery
Slice before Dye
26
Unit 2
Let’s Investigate! Lab
Slice after Dye
Whole Stalk after Dye
Unit 2
How do plants
change and grow?
Review
Lesson 1
How do plants use roots and stems to grow?
1
Match the columns.
a) Roots
is an example of plants
with fibrous roots.
take in water and
minerals from the soil.
support the leaves,
flowers, and fruits.
are examples of
taproots.
b) Stems
c) Carrots
d) Grass
2
Write two types of stems.
Lesson 2
How do plants use flowers and cones to reproduce?
3
Mark () the items that play a role in the process of pollination.
roots fruit
4
petals
pollen
bee
stem
Write the four stages of a flowering plant life cycle.
1. seed
2. growth
3. pollination
4.
Got it? Quiz
Got it? Self Assessment
Unit 2 27
Unit
3
1
Living Things
How do living things
grow and change?
Look and match. Label.
caterpillar
joey
kangaroo
How is each baby animal different
from the adult? Describe with a
partner.
3
What do baby animals need to
grow? Discuss as a class.
Unit 3
the life cycles of different
animals.
ō how to classify animals.
ō
frog
butterfly
tadpole
2
28
I will learn
T hi nk !
Why do
kangaroos carry
their young?
Lesson 1 . What are the life cycles of some animals?
1
Read and number the photos (1–3) to show the
sequence in the life cycle of a bald eagle.
Life Cycles
An animal’s life starts out as an egg. Sometimes the
egg develops into a young animal inside the mother’s
body. Then the mother gives birth to a live young. For
other animals, the mother lays an egg outside of her body.
Eagles have their young in this way. First, the mother eagle
lays an egg. Next, the eaglet, a young eagle, develops
inside the egg. Finally, the eaglet hatches when it is ready.
Key Words
larva
ō pupa
ō metamorphosis
ō amphibian
ō gills
ō lungs
ō
After birth, an animal begins to grow. It develops into
an adult, and then it can reproduce. Eventually, it dies.
Its life cycle is complete.
2
With a partner, complete the graphic organizer to sequence the steps in an
eagle’s birth.
First
Next
Finally
Let’s Explore! Lab
Unit 3 29
3
Read and label the stages in a butterfly’s life.
Life Cycle of a Butterfly
The life cycle of a butterfly has four stages, as shown
in the diagram. A butterfly looks very different at each
stage of its life. It also behaves in different ways.
Adult
Larva
Egg
Pupa
2
The butterfly larva is
called a caterpillar. It
hatches from the egg.
The caterpillar eats plants.
It must eat a lot to grow
and store energy. The
caterpillar sheds its skin
several times as it grows.
1
A butterfly begins
life in a tiny egg.
The egg in this
picture has been
magnified, or made
to look bigger.
4
The adult butterfly breaks out
of the chrysalis. It has wings,
long legs, and antennae.
It flies away to find a mate. It
will lay eggs if it is a female.
Some adult butterflies feed on
the nectar of flowers. Some do
not feed at all. Eventually, the
butterfly will die.
4
30
Unit 3
I Will Know...
3
A hard covering, or
chrysalis, forms around
the larva. The larva is
now called a pupa. As a
chrysalis, the insect does
not eat, and it hardly
moves. During this stage,
the insect grows wings
and long legs.
During which stage does a butterfly
eat the most? Why does it eat so much
during this stage? Discuss with a partner.
5
Read, look, and circle the stage during which a frog lives on land.
Life Cycle of a Frog
Some animals change form as they develop. This change in form during
an animal’s life cycle is called metamorphosis. Many insects go through
metamorphosis. Frogs do, too. Frogs are amphibians. Amphibians live in water
during some parts of their lives. They live on land during other parts of their lives.
1
2
Egg
Mother frogs often lay
hundreds or thousands
of eggs in the water.
The eggs are surrounded
by a jelly-like material.
4
Adult Frog
The adult frog lives on land
and in water. It returns to the
water to lay its eggs. Some
frogs reproduce many times
before they die.
Tadpole
A tadpole hatches
from each frog egg.
Tadpoles live
underwater
and breathe
with gills.
3
Growing Tadpole
The tadpole changes as it
grows. Its tail becomes shorter,
and its legs begin to grow. It
develops lungs for breathing,
and its gills disappear.
6
Write a list of the parts of a tadpole’s body that are similar to a fish’s body.
a)
b)
Unit 3 31
7
Read, look, and number the stages in order.
Life Cycle of a Mammal
Unlike amphibians and insects, young mammals do not change very much as they
become adults. Many mammals look like their parents when they are born. Like you,
they grow as they get older.
1
2
4
3
Kitten
Young bobcats
are called kittens.
The mother bobcat’s
body makes milk.
The kittens drink
the milk.
8
32
Adult
When the
young bobcats
grow to be
adults, they can
reproduce.
Egg
Young bobcats develop
from eggs inside the
mother’s body. They
are born when they are
ready to live outside the
mother’s body.
Growth
The young
bobcats grow
bigger. The
mother bobcat
takes care of
them.
With a partner, name two ways a young bobcat is similar to an adult bobcat.
Name two ways they are different.
Unit 3
Lesson 1 Check
Got it?
60-Second Video
Lesson 2 . How can you classify animals?
1
Key Words
ōtrait
Read and circle three ways that animals
are classified.
ōvertebrate
ōscales
Classify Animals
ōcold-blooded
Animals are classified into groups. Animals can be
classified by what we want to learn about them. Animals
can also be classified by how they look.
ōwarm-blooded
ōinvertebrate
ōarthropod
Scientists identify body features, such as long ears or
short fur, to classify animals. A trait is a feature passed on
from a parent. Traits can include an animal’s behavior or
its physical characteristics. Animals can also be classified
by where they live or how they act.
One animal can be placed into different groups. For
example, a group of animals that eat mice can include
snakes, hawks, and owls. A group of animals that fly
can include hawks and owls, but not snakes.
2
Read and circle the best title for the paragraph.
One main characteristic scientists use to classify animals
is the presence or the absence of a backbone. An animal
with a backbone is called a vertebrate. For example,
cats, birds, and fish are vertebrates. Vertebrates may look
different, but they all have a backbone and other bones.
Bones grow as the animals grow. Bones support the body.
This allows some vertebrates to grow very big.
a) Bones Are Important
b) Animals with Backbones
c) Cats, Birds, and Fish
T hi nk !
What allows a
giraffe to grow
so tall?
Let’s Explore! Lab
Unit 3 33
3
Read, look, and number to match.
Groups of Vertebrates
1 Fish
Fish are vertebrates that live in water. Most fish have
slippery scales, breathe through gills, and lay eggs.
Most fish are cold-blooded vertebrates.
2 Amphibians
Amphibians are cold-blooded vertebrates. They have
smooth, moist skin. They hatch from eggs. Frogs,
toads, and salamanders are amphibians. Most young
amphibians live in water. They get oxygen through
their gills and skin. Most amphibians develop lungs to
breathe air when out of the water.
3 Reptiles
Snakes, lizards, turtles, and crocodiles are reptiles.
Reptiles are cold-blooded vertebrates. They have
dry, scaly skin. They breathe air through lungs. Most
reptiles lay eggs.
4 Birds
Birds are warm-blooded vertebrates with feathers
and bills. Feathers help birds stay warm. Wings
and light bones help most birds fly. They breathe
air through lungs. All birds hatch from eggs.
5 Mammals
The vertebrates you probably know best are mammals.
Mammals are warm-blooded vertebrates. They usually
have hair that keeps them warm. Mammals breathe
air through lungs and feed milk to their young. Most
mammals are born alive instead of hatching from eggs.
34
Unit 3
4
Read and label the invertebrates.
Animals without Backbones
Most animals do not have bones or skeletons inside
their bodies. Animals without backbones are called
invertebrates. Sea stars, butterflies, and spiders are
invertebrates.
Invertebrates have other structures to give them their
shape. A soft sac filled with liquid supports worms
and sea jellies. A hard shell supports clams and crabs.
Insects have a hard covering on the outside of their
bodies. These kinds of structures cannot support very
big animals. Most invertebrates are smaller than most
vertebrates.
Classify Different
Animals
Draw an animal.
Describe two features,
such as how the animal
moves and what it eats.
Draw another animal.
Compare the features.
Write how the animals
are alike and different.
Then classify them.
You may not notice some invertebrates because
many are very small. Yet invertebrates live all over
Earth. In fact, there are many more invertebrates
than vertebrates. For example, several million tiny
roundworms may live in one square meter of soil.
5
Read and circle T (true) or F (false). Correct the false statements.
1. Invertebrates have bones.
T
/
F
2. Some invertebrates have hard shells or coverings.
T
/
F
3. Most large animals are invertebrates.
T
/
F
Unit 3 35
6
Read and match.
Groups of Invertebrates
Sea Jellies
Sea jellies have soft bodies and long,
stinging body parts. The body of a sea jelly
is made mostly of water. A sea jelly stuns its
prey before pulling it into its stomach. Most
sea jellies live in the ocean.
Worms
Worms are animals with long, soft bodies
and no legs. These invertebrates help keep
soil healthy.
Mollusks
Mollusks have soft bodies. Many mollusks
have hard shells and eyes. Some mollusks
include octopuses, squids, clams, and snails.
Arthropods
Arthropods are the largest group of
invertebrates. An arthropod is an animal that
has a hard covering outside its body. The
bodies of arthropods have more than one
main part, and their legs have joints. Insects,
spiders, and crabs are all arthropods.
7
Look and classify each animal in your notebook.
Spider
Orangutan
Slug
invertebratmollusk
36
Unit 3
I Will Know...
Dolphin
8
Read and fill in the chart. Then brainstorm
with a partner to complete it.
Classification by Animal Birth
Another trait that helps scientists classify
animals is the way they give birth. Most animals
begin life as small eggs. The eggs grow to
different sizes. The young animals are then
born in different ways.
Eggs
Many animals hatch from eggs. For
example, all birds hatch from eggs. Most fish,
amphibians, and reptiles also hatch from eggs.
Crocodiles lay eggs, as do most other reptiles.
After growing in the eggs for two or three
months, young crocodiles hatch from the eggs.
Animals That Lay Eggs
1)
2)
3)
4)
Live Birth
Most mammals have live births. This means
that the young animal is born instead of hatching
from an egg. You may have seen images of a lion
with her young cubs. She gave live birth to the
cubs after being pregnant for about four months.
5)
Animals That Have Live Births
1)
2)
3)
4)
5)
Lesson 2 Check
Got it?
60-Second Video
Unit 3 37
Let’s Investigate!
Materials
What do leaves have in common?
1. Spread out the leaves. Observe them.
Which ones have similar shapes?
2. Make a yarn circle for each kind of shape.
You may have from 3 to 5 groups.
10 leaves or
leaf pictures
3. Place leaves with similar shapes in
the same circle.
4. Draw each leaf in its group. Explain
how the shapes of each group are alike.
5 yarn circles
D
A
B
C
G
E
F
J
I
H
38
Unit 3
Let’s Investigate! Lab
Unit 3
How do living things
grow and change?
Review
Lesson 1
What are the life cycles of some animals?
1
During this stage in a butterfly’s life, a hard covering
forms around the caterpillar.
a) egg
b) larva
d) adult
2
Compare the birth of a baby eagle to the birth of a
baby cat. How are they different?
Lesson 2
How can you classify animals?
3
Compare amphibians and reptiles. List one way they
are the same and one way they are different.
Same: .
Different:
4
Read the classifications and match.
a) invertebrate, arthropod
eagle
b) vertebrate, warm-blooded, lays eggs
clam
c) vertebrate, cold-blooded, lays eggs
frog
d) vertebrate, warm-blooded, live birth
spider
e) invertebrate, mollusk
bobcat
Got it? Quiz
Got it? Self Assessment
Unit 3 39
Unit
4
Ecosystems
How do living
things interact?
I will learn
what an ecosystem is.
ō how living things get
energy.
ō how ecosystems change.
ō
1
Look and label.
grassland
sunlight
coral reef
rain forest
marsh
soil
2
With a partner, name three living things
that you can find in a marsh, in a
rain forest, and on a coral reef.
3
What do living things need to live?
Discuss as a class.
40
Unit 4
T hi nk !
How do bison help
grassland plants
grow and stay
healthy?
Lesson 1 . What is an ecosystem?
1
Read and list two living and two nonliving
things mentioned in the text.
Places for Living Things
Key Words
ecosystem
ō habitat
ō population
ō community
ō
How is the place where a bear lives different
from the place where an earthworm lives? Each
kind of living thing needs a certain environment.
A living thing’s environment is everything
around it. An environment has living and
nonliving parts. The living parts include plants,
animals, and other living things.
Sunlight is a nonliving part of an environment.
The sun’s rays warm other nonliving parts, such
as the air, water, and soil. Because of the sun’s heat,
Earth’s air, water, and soil are warm enough for
living things.
Living Things
2
Nonliving Things
Say two living and two nonliving things that appear in the photo below.
3
With a partner, compare where a bear lives and
where earthworms live. List one way they are the
same and one way they are different.
Same:
Different:
Explore My Planet!
Unit 4 41
4
Read and underline the names of
all the living things mentioned in
the captions.
Parts of an Ecosystem
The living and nonliving parts of an
environment interact. Interact means to act
together. These interacting parts make up an
ecosystem. The pictures on this
page show a marsh. A marsh is a type
of wetland ecosystem.
The living parts of an ecosystem depend
on nonliving parts. For example, plants need
sunlight, soil, air, and water to grow. The
living parts also depend on one another. For
example, animals eat other living things.
Some animals use plants
for shelter.
5
With a partner, list three more
animals that you might find
in this wetland.
1.
2.
3.
42
Unit 4
I Will Know...
Read both texts. What is the habitat of the bluespot
butterflyfish in the picture below? Discuss with
a partner.
6
Habitats
The place where a living thing makes its home is its
habitat. A habitat has everything that a plant or animal
needs to live. A habitat can be the water in a wetland.
It can be the soil beneath a rock.
Groups within Ecosystems
This monkey’s habitat is the
trees in a rain forest.
All the living things of the same kind that live in
the same place make up a population. The coral reef
ecosystem shown below includes many different populations. For example, all of the
bluespot butterflyfish living around the reef make up one population. A coral reef
also may have populations of crabs, clams, sharks, and other animals.
All the populations that live in the same place make up a community. Populations
in a community depend on one another.
Read and complete the sentences. Then check your answers with a partner.
7
community
population
1. All the red squirrels in a forest are a
.
2. Squirrels, birds, and insects that live in the same forest form
a
community
Th in k!
How do fish in the
sea interact with
nonliving things?
.
Lesson 1 Check
Got it?
60-Second Video
Unit 4 43
Lesson 2 . How do living things get energy?
1
Key Words
producer
ō consumer
ō decomposer
ō food chain
ō herbivore
ō carnivore
ō omnivore
Read and match the columns.
ō
Energy Roles in Ecosystems
Every living thing needs energy to stay alive and
grow. Living things get energy in different ways. Green
plants use sunlight along with air and water to make
sugar. The sugar is the plants’ food. It gives plants the
energy they need. A living thing is called a producer if
it makes, or produces, its own food.
Many living things cannot make food. They get energy from
food that they eat, or consume. A living thing that eats other
organisms is called a consumer.
Th in k!
How are a
consumer and
When plants or animals die, their stored-up energy is unused. a decomposer
similar?
Decomposers use this energy. A decomposer is a living thing
that breaks down waste and dead plant and animal matter.
a) Producers
need to eat to get their energy.
b) Consumers
break down dead plants and
animals for energy.
c) Decomposers
make or produce their own energy.
2
Read and label each living thing as a producer,
consumer, or decomposer. Then check your
answers with a partner.
Mushrooms break down
a dead tree for energy.
44
Unit 4
Let’s Explore! Lab
Puffins eat fish to get energy.
A fern plant takes in
sunlight to make food.
3
Read and look at the diagram. Circle the consumer that is a carnivore in red
and the consumer that is a herbivore in green.
Food Chains
A food chain shows the transfer of
energy from one living thing to another.
In a food chain diagram, arrows
show the flow of energy. The first link in
the food chain on these pages is the sun.
A producer, such as grass, is the next
link. The producer uses the sun’s energy
to make food. Next, a consumer, such
as a prairie dog, eats the producer. The
producer passes energy to the consumer.
That consumer may then be eaten by
another consumer, such as an eagle. In
this way, energy from a producer can be
passed from one consumer to another.
Some consumers eat only plants.
They are called herbivores. Some
consumers eat only other animals. They
are called carnivores. Other consumers
eat both plants and animals. They are
called omnivores.
Grassland Ecosystem
I Will Know...
Unit 4 45
4
Read and complete the lists with words from the
captions. Then check your answers with a partner.
Animals that eat grass:
1)
Food Webs
2)
Do you eat the same food at every meal? Some
animals do not always eat the same things either.
Ecosystems have many food chains. Food chains
combine to form a food web. A food web is a system
of overlapping food chains in an ecosystem. Food
webs show that energy flows in many different ways
in an ecosystem. Energy can flow from one producer
to many consumers. One consumer can be eaten by
many other consumers.
3)
4)
Animals that eat prairie dogs:
1)
golden eagle
2)
black-footed ferret
3)
coyote
badger
golden
eagle
snake
black-footed ferret
mouse
grasshopper
cattle
coyote
prairie dog
energy from
the sun
grasses
46
Unit 4
Lesson 2 Check
Got it?
60-Second Video
Lesson 3 . How do ecosystems change?
1
Key Words
resources
ō drought
ō adaptation
Read and match each cause with its effect.
ō
Ecosystem Change
Ecosystems are always changing. Think about what
happens when a 200-year-old tree falls in a storm.
Throughout its life, the tree shaded the forest floor.
Now the forest floor will receive much more sunlight.
Seedlings that require a lot of sunlight will have a
chance to grow. Other plants that grow
best in shade might not survive.
The change may affect
animals, too. Birds that nested
in the tree may need to
find a new home. But the
fallen tree may provide a
habitat for salamanders
and other animals.
a) A tree falls down and birds
lose their home.
It will provide a new habitat
for other animals.
b) The forest floor receives
more sunlight.
Birds will have to find a new
home in another tree.
c) The tree lies down on the
forest floor.
Plants that need sunlight
will grow.
2
With a partner, discuss another cause and effect of a tree falling down in a forest.
Explore My Planet!
Unit 4 47
3
Read and label the effects of groundhogs.
Living Things Cause Change
All living things need resources like water and food. Living things get what they
need from their environments. As they do this, they cause changes in their environments.
Look at the groundhogs in the pictures. Groundhogs live underground in tunnels, or
burrows. As they dig their burrows, they change the environment. These changes can
be harmful. Groundhogs can damage crops, lawns, and the roots of trees. But some
living things benefit from changes that groundhogs cause. Foxes, rabbits, and other
animals often live in burrows made by groundhogs. Groundhogs also improve soil
by mixing it as they dig. This benefits plants that grow in the soil.
Positive effect
48
Unit 4
Negative effect
I Will Know...
4
Read and underline four changes that natural events can cause in ecosystems.
Natural Events Cause Change
Natural events can also change ecosystems. Fires can
burn forests. Hurricanes can wash away beaches and
cause floods. Floods can knock down trees and destroy
animal habitats. Droughts, or the lack of rain, can
cause animals and plants to die.
Not all living things are harmed by changes to
ecosystems. A forest fire may destroy many trees and
animals’ homes. But the fire also clears dead plants
and wood from the forest floor. Then trees that were not
harmed by the fire have more space to grow. Plants that need more sunlight can also
grow. Ash from the fire makes soil healthy. Ash contains minerals that plants need.
Seasonal Change
In some ecosystems,
the cycle of the seasons
brings major changes.
For example, winters may
be very cold and snowy.
Some plants die in winter.
Food may be hard to find
for some animals.
Many plants and animals have
adaptations that help them survive these changes. An adaptation is a trait that helps a
living thing survive in its environment. For example, some trees shed their leaves before
winter. This reduces the amount of water they need to take in during winter. Some
animals, such as bats and ground squirrels, hibernate, or sleep, through the winter.
5
In which different ways can seasons affect the tree in the pictures?
Discuss as a class.
Lesson 3 Check
Got it?
60-Second Video
Unit 4 49
Let’s Investigate!
Materials
What can you find in your local ecosystem?
1.
Use 3 strings to divide a square meter of land
into 4 squares. Measure the length of each side
to make sure the sections are squares. Use index
cards to label the squares A, B, C, and D.
2.
Use a hand lens to look for living things in
Square A. Record the living things you observe.
3.
Observe the nonliving things. Record the
nonliving things you find.
4.
Repeat for each square.
square meter of land
3 pieces of string
hand lens
4 index cards
meterstick
Observations
Square
Living Things
A
B
C
D
50
Unit 4
Let’s Investigate! Lab
Nonliving Things
Unit 4
Review
How do living
things interact?
Lesson 1
What is an ecosystem?
1
Describe how a raccoon in a marsh interacts with
a living part and a nonliving part of the ecosystem.
a)
b)
Lesson 2
How do living things get energy?
2
Mark () the things that are not part of a prairie
food chain.
shark
cow
prairie dog
sun
grasses
bear
butterflyfish
eagle
puffin
Lesson 3
How do ecosystems change?
3
List four things that can make ecosystems change.
1.
2.
3.
4.
Got it? Quiz
Got it? Self Assessment
Unit 4 51
Unit
5
1
Body and Illness
How can I keep
my body healthy?
Look and label the pictures.
sneeze
fever
I will learn
what causes some
diseases.
ō how to avoid getting
some diseases.
ō
microscope
vaccine
mosquito
bacteria
2
Which of the above things can make
you sick? Discuss with a partner.
3
Why is it important to cover your
nose and mouth when you sneeze?
Discuss as a class.
T hi nk !
Why is it hard to
catch a cold at the
North Pole?
52
Unit 5
Lesson 1 . What causes different diseases?
1
Key Words
infectious disease
ō microorganism
ō noninfectious disease
ō abnormal
ō pathogen
ō toxin
ō immune system
ō allergen
Read and complete the graphic organizer.
ō
Infectious and Noninfectious Diseases
As you already know, exercising, eating well, getting
enough sleep, and washing your hands can help you stay
healthy. Sometimes, though, you still might become sick.
There are two types of diseases that you might get.
The first are infectious diseases. They are caused by
organisms invading and growing in your body. Most of
these organisms are so small you can only see them with
a microscope. That’s why they’re
called microorganisms.
The second kind of diseases
are called noninfectious diseases.
They are not caused by an
organism infecting your body.
They happen when parts of
your body start to work in an
abnormal, or unusual, way.
Asthma is a
noninfectious disease.
Chickenpox is an
infectious disease.
Main Idea
2
Why is a broken arm called an injury and not a disease?
Discuss as a class.
Let’s Explore! Lab
Unit 5
53
3
Read and circle T (true) or F (false). Correct the false statements with a partner.
Causes of Infectious Diseases
Any organism that can cause a disease is called
a pathogen. There are four major types of pathogens.
These bacteria
cause strep throat.
This virus causes
the common cold.
1. All organisms are pathogens.
T
/
F
2. Some bacteria can attack your cells directly.
T
/
F
3. Viruses are nonliving organisms.
T
/
F
4. Viruses produce toxins that damage your cells.
T
/
F
4
In small groups, pick one of the pathogens below and research it. Tell the rest
of the class whether it is a bacterial or viral pathogen and what disease it causes
in humans.
rabies
54
Unit 5
staphylococcus
I Will Know...
H1n1
listeria
5
Read and underline three diseases caused by parasites or fungi.
This parasite causes
hiker’s disease.
Fungi like these can
cause athlete’s foot.
6
Put the pathogens in order from smallest to largest.
parasites
viruses
bacteria
7
smallest
largest
Read and underline the type of blood cells that
make up your immune system.
Immune System
The white blood cells in your blood make up your
immune system. Your immune system attacks
pathogens when they infect your body. Your immune
system is your body’s natural defense against disease.
When you are sick, your body
makes more white blood cells
to fight the disease.
Unit 5 55
8
Read and circle T (true) or F (false). Correct the false statements with a partner.
Noninfectious Diseases
Noninfectious diseases are not caused by pathogens. A
person cannot pass a noninfectious disease to another person.
Here are some of the more common noninfectious diseases.
Many people are allergic
to flower pollen.
The medicine in an
inhaler can help stop
an asthma attack.
1. Noninfectious diseases can be passed from one person to another.
T
/
F
2. An allergy is caused by your immune system being too sensitive.
T
/
F
3. Allergies are never very serious.
T
/
F
4. Asthma causes your airways to open up.
T
/
F
9
Label each either A (allergen) or P (pathogen).
P
A
flu virus
56
Unit 5
tobacco smoke
A
dust
P
Salmonella bacteria
10
Read and underline the different types of diabetes.
Discuss as a class.
People with diabetes
have to check the
sugar in their blood by
pricking their fingers.
Eating sugary
foods can cause
type 2 diabetes.
11
Fill in the blanks.
sugar
develop
exercise
type 2
Diabetes is a
noninfectious
type 1
disease because it is not caused by a
pathogen. When someone has diabetes, they have too much
in their blood. If you are born with diabetes, you have
type 1
type 2 diabetes if they don’t eat
diabetes. People can
well or get enough
suar
exercise
. More and more people are getting
diabetes because they drink too much soda pop and eat
too many sugary foods.
Lesson 1 Check
Got it?
60-Second Video
Unit 5 57
Lesson 2 . How can you avoid getting diseases?
1
Read and underline three ways you can get sick
from a sick person.
How Infectious Diseases Spread
Pathogens can infect you in many ways. When you
come close to or touch an infected person, they can infect
you. Pathogens in soil, food, water, or contaminated
objects also can infect you. Sometimes even an animal
bite can cause a pathogen to infect you.
Infected People: A person can pass pathogens to
another person when they touch, for example, when
they kiss or shake hands. Some pathogens also spread
without people touching each other. When a person
with a cold sneezes, the cold viruses can spread
into the air. Then, someone else can breathe in
those viruses and develop a cold, too.
Soil, Food, and Water: Some pathogens can live in
the soil. Other pathogens live in the water or in food.
For example, Salmonella bacteria are
very common in chicken. When you
eat chicken that hasn’t been cooked
long enough, you can get food
poisoning, which can cause you to
Drinking dirty water throw up or have diarrhea.
like this might
make you sick.
2
58
Why is it important to wash fresh vegetables and
fruit before you eat them? Discuss with a partner.
Unit 5
Let’s Explore! Lab
Key Words
Salmonella
ō antibiotic
ō vaccine
ō antibodies
ō symptoms
ō chronic
ō
Covering your nose when
you sneeze will help
pathogens not spread.
Read and underline three diseases that can be
spread by objects or animals.
3
Contaminated Objects: Some pathogens can
live for a while outside of a person’s body. These
pathogens can infect people when they use an
object that an infected person used.
The fungus that causes athlete’s foot spreads this
way sometimes. If someone who has athlete’s foot
walks barefoot in a place that you later walk barefoot in,
you might get athlete’s foot.
Infected Animals: When an animal that is infected with a pathogen
bites a person, sometimes the pathogen can infect
that person. For example, rabies, a serious
disease that can attack the brain, can pass
to humans when an infected animal
bites them. In tropical areas, people
can develop malaria if mosquitoes that
carry the malaria parasite bite them.
Bites from infected
raccoons or dogs can
spread rabies to humans.
4
Match the beginning to the ending of each sentence.
a) Colds can be spread by
contaminated food.
b) Food poisoning can be caused by
infected mosquitoes.
c) Athlete’s foot can spread by
an infected person’s sneeze.
d) Malaria can spread by
fungi on contaminated objects.
I Will Know...
Unit 5 59
5
Read and fill in the blanks to complete the sentences.
How Some Infections Are Treated
If someone has a bacterial infection, doctors will often
treat them with antibiotics. Antibiotics are medicines
that will kill the bacteria in your body. It is important to
always take all the antibiotics that a doctor prescribes.
If you stop taking antibiotics early, some of the strongest
bacteria might survive and make you sick again. Parasites
and fungi are also living pathogens. A doctor might treat
them with antiparasitic or antifungal medications.
One common
antibiotic is made
naturally by a mold.
How Vaccines Prevent Diseases
Viruses are nonliving, so antibiotics do not work against
them. Instead, doctors use your body’s own immune
system to attack viruses. Doctors do this by giving you a
vaccine before you get infected. A vaccine contains
a weakened form of a virus. When this weakened virus
is injected into your bloodstream, your immune system
becomes ready to produce many antibodies, which are
special molecules in your blood that attack viruses. That
way, if you are infected by that virus again, the antibodies
protect you from getting sick. Vaccines are very specific.
That’s why you need separate vaccines for different viral
diseases, like measles and the flu.
1. Antibiotics kill
2. Viruses are
3. A vaccine contains a
60
in your body.
, so antibiotics do not work against them.
form of a virus.
are special molecules in our body that will attack viruses.
4.
6
Vaccinations can
prevent many
viral infections.
Why do we have to get separate vaccines for different diseases?
Discuss with a partner.
Unit 5
7
Read and number the steps for how a cold can spread from
a sick person to you.
Some Ways to Keep Your Body Healthy
Did you know that washing your hands is the most
effective way of preventing the spread of many illnesses?
You should wash your hands several times a day. It is
especially important to wash your hands before eating,
after going to the bathroom, and if you are sick with an
infectious disease or spend time with a sick person. The virus
that causes colds can stay on your hands. If you touch your eyes,
nose, or mouth, the virus can infect you. Washing your hands
inactivates the virus so you don’t spread it to yourself or other people.
8
Read and underline two things a doctor can do even if you don’t seem to be sick.
How Going to the Doctor Can Keep You Healthy
Your doctor can give you antibiotics to treat some
infections and vaccines to avoid some viral infections. Even
if you don’t have symptoms, or signs that you are sick,
seeing your doctor regularly is important. Your doctor can
check your overall health and can discover if you have
a noninfectious disease and treat it. Some noninfectious
diseases, like diabetes, are called chronic because they last
a long time and can come back again and again. Your
doctor can monitor these types of diseases and make sure
they don’t get worse or cause other problems.
9
What are some other ways to stay healthy? Discuss as a class.
Lesson 2 Check
Got it?
60-Second Video
Unit 5 61
Materials
Let’s Investigate!
How much sugar is there in a can
of soda pop?
1 can of
soda pop
sugar
2 clear
plastic cups
scale
1.
Put a plastic cup on the scale. Turn the scale on.
Make sure the scale reads 0.
2.
Add how much sugar you think is in a can of
soda pop.
3.
Record the weight.
4.
Read the back of the can of soda pop to see
how many grams of sugar it has.
5.
Repeat step 1 with the second cup.
6.
Add sugar to the cup until you have the same
number of grams that you found in step 4.
7.
Compare your prediction to your observation.
Grams of Sugar
Prediction
Observation
The nutrition label
will tell you how much
sugar is in the can.
62
Unit 5
Let’s Investigate! Lab
Unit 5
How can I keep
my body healthy?
Review
Lesson 1
What causes different diseases?
1
Circle the true statements. Correct the false ones.
Some bacteria are pathogens.
c) Viruses are living microorganisms.
b)
2
Match the two columns.
a) The flu is caused by
b) Food poisoning is caused by
bacteria.
c) Allergies are caused by
an immune system that is
too sensitive.
d) Diabetes can be caused by
Lesson 2
How can you avoid getting diseases?
3
Mark () the ways that pathogens can spread.
antibiotics
asthma
4
shaking hands
dirty water
flower pollen
contaminated objects
Complete these statements with the words in the box.
viruses
malaria
antibiotics
chronic
kill bacteria.
a) Medications called
b) A vaccine helps your body to destroy
.
disease can last a long time and come back.
c) A
if an infected mosquito bites you.
d) You can get
Got it? Quiz
Got it? Self Assessment
Unit 5 63
Earth and Weather
Unit
6
How do forces cause changes
on Earth’s surface?
I will learn
about the water cycle.
ō features and changes on
Earth’s surface.
ō about weathering and
erosion.
ō
1
Look and label.
landslide
snow
clouds
earthquake
Earth
hail
2
What do the clouds, snow, and hail
have in common? Discuss with a partner.
3
How can earthquakes change Earth’s
surface? Discuss as a class.
64
Unit 6
T hi nk !
How could a
tree break
apart rock?
Key Words
Lesson 1 . What is the water cycle?
1
Read and complete the graphic organizer to show
the cycle of a water particle.
Water on Earth
water cycle
ō evaporation
ō condensation
ō precipitation
ō
You could call Earth “the blue planet.” That is
because nearly three-fourths of Earth’s surface is
covered by water. Most of that water is in the ocean.
Earth’s water is found in different forms. It can move
from one place to another. Suppose you follow a particle
of water for a year. First, you might find the water
particle crashing on a beach as part of an ocean wave.
Next, you might find it drifting in the sky as part of a
cloud. Finally, you might find it floating down as snow.
First
Next
A water particle crashes
The water particle drifts
.
2
Finally
The water particle
might float
.
.
With a partner, number the photos (1–3) to show
the forms of the water particle described in the
graphic organizer.
Reduce Water Use
There is only a certain
amount of fresh water
on Earth. It must be used
again and again. Think
about how you use water.
Describe three ways that
you could use less water.
I Will Know...
Explore My Planet!
Unit 6 65
3
Read and label the stages in the water cycle.
Water Cycle
The movement of water from Earth’s surface into the air and back again is the
water cycle. The water cycle is important because it gives Earth a constant supply
of fresh water. Most of Earth’s water is salty ocean water that you cannot drink.
Water changes form, or state, as it moves through the water
cycle. After water moves through the stages of the water cycle,
the cycle begins again. Read the captions and follow the arrows
to find out more.
Storage
66
Unit 6
Condensation
Lesson 1 Check
Precipitation
Got it?
Evaporation
60-Second Video
T hi nk !
Why is the sun
important to the
water cycle?
Lesson 2 . How do we describe features
of Earth’s surface?
1
Read and underline three landforms in the text.
Landforms
The outer surface of Earth is a layer of rock called
the crust. The crust covers all of Earth. The crust can have
different shapes, such as mountains, hills, and valleys.
Each shape is an example of a landform. A landform is
a solid feature of Earth’s crust.
Key Words
landform
ō landslide
ō volcano
ō lava
ō earthquake
ō faults
ō
Landforms are constantly changing. Some changes
happen quickly. For example, during landslides, rocks and
dirt move rapidly down a slope. Other changes happen
slowly. Mountains can take millions of years to form.
2
Read and circle T (true) or F (false).
With a partner, correct the false statements.
Bodies of Water
Bodies of water are another type of feature found on Earth’s surface. Moving water
is one of many forces that can shape landforms. Rivers can act like saws, cutting
through rock. Flooding rivers deposit sediment on their banks. Ocean waves break
apart rocks and move sand. These processes are constantly changing Earth’s crust.
1. Rivers, mountains, and oceans are bodies of water.
T
/
F
2. Moving water cannot change Earth’s surface.
T
/
F
3. Rivers and ocean waves can break apart rocks.
T
/
F
3
What bodies of water exist near your school? Discuss as a class.
Explore My Planet!
Unit 6
67
4
Read the captions. With a partner, list the features that are NOT landforms.
Features on Earth’s Surface
Features on Earth’s surface that are
not landforms:
1. lacier
2. ocean
3. lake
4. river
68
Unit 6
I Will Know...
5
Read and number the events (1–4) to show the sequence of a volcano erupting.
Rapid Changes to Earth’s Surface
When magma
flows onto Earth’s
surface, it is called lava.
Volcanoes
Volcanoes begin in the layer below
Earth’s crust called the mantle. Here,
melted rock called magma forms. First,
magma collects in a pocket called a
magma chamber. Next, magma pushes
up through weak spots in the crust. Then,
magma erupts through a bowl-shaped
crater. Magma that flows onto Earth’s
surface is called lava. Finally, the lava
cools and hardens, forming igneous rock.
crater
The lava
cools and hardens,
forming rock.
Earthquakes
Earth’s crust is broken into large pieces
that move. Most of the time these pieces
move very slowly, but sometimes they can
shift suddenly. The sudden shift can make
the ground shake. This shaking is an
earthquake. Most earthquakes happen
along faults, or large cracks in the crust.
An earthquake’s shaking can make new
cracks appear in Earth’s surface. It can
also cause landslides.
Magma
pushes upward
through weak spots
in Earth’s crust.
Magma collects
in a magma chamber.
magma chamber
6
Lesson 2 Check
Why do volcanoes cause rapid
and dangerous changes to Earth’s
surface? Discuss as a class.
Got it?
60-Second Video
Unit 6 69
Lesson 3 . What are weathering
and erosion?
Key Words
weathering
ō erosion
ō mudflow
ō rockslide
ō
1
Read and complete the sentences.
Weathering by Plants
Landforms are the solid features found
on Earth’s surface, such as mountains and
valleys. Landforms change constantly. For
this to happen, rocks in landforms must first
break apart. Weathering is any process
that breaks rocks into smaller pieces.
Weathering can be very slow. Some
changes might take centuries. Others may
take less than a year. Weathering goes on
all the time.
Plants sometimes cause weathering.
Their roots can grow into cracks in rocks.
As the roots get bigger, they can split and
break up the rocks.
roots
landforms
weathering
1. Valleys, hills, and mountains are examples of
.
2.
takes place when rocks
are broken down into smaller parts.
Weatherin
3. When the
of a tree get
bigger and stronger, they can break up rocks.
2
70
Unit 6
Let’s Explore! Lab
What might happen as the tree roots in the
picture continue to grow? Discuss as a class.
3
Read both texts. With a partner, label each of
water’s effects with the words from the box.
Weathering by Water
Water can cause weathering, too. Water changes
the minerals in some rocks. The rocks become weakened
and may begin to break apart.
Water can also cause weathering when it freezes and thaws.
Water can get into cracks in rocks. When water freezes, it expands, or grows larger.
The ice pushes against the sides of the cracks. Over the years, the rocks may break apart.
Erosion by Water
Sometimes weathered material stays in place.
Sometimes it is picked up and slowly or quickly carried
to other places. The movement of weathered material is
called erosion.
Water is one of the causes of erosion. Rainwater
can carry away soil from farm fields. Waves cause
erosion along shorelines. Rivers carry bits of rock from
one place to another. Sand and mud flow over a river’s
banks during a flood.
Glaciers can also cause erosion. Glaciers are huge bodies of ice and snow that
move slowly over Earth’s crust. As a glacier moves, it wears away bits of rock and
soil and carries them off.
Weathering
Water can get into
rocks. If it freezes,
it expands and
breaks the rocks.
Ocean waves
move sand and
form shorelines.
Erosion
When it rains,
water washes
soil away from
mountains.
When rocks stay
in water for a long
time, they can break
down or dissolve.
I Will Know...
Unit 6 71
Read and number the effects (1–4) to show the sequence of erosion by wind in
deserts. Then check your answers with a partner.
4
Erosion by Wind
Erosion by wind is common in dry regions, such as
deserts. Wind can carry dry sand and soil to other places.
Few tall plants grow in deserts. This means there is little to
stop the particles of sand and soil from blowing around.
Sand and soil particles can also cause weathering
when blown by the wind. The particles bump into
rocks and break off tiny grains. Over time, more
grains are broken off. The rocks slowly change.
Sand particles break off tiny grains from rocks.
First, wind blows sand particles to other places.
Over time, the rocks slowly change.
Then sand particles bump into rocks.
5
Read and underline two other causes of erosion.
Other Causes of Erosion
Gravity also causes erosion. Gravity pulls rocks and
soil downhill. The material moves slowly if the slope is
gentle. It can move quickly on steep slopes. A mudflow
is the quick movement of very wet soil. A rockslide is
the quick movement of rocks down a slope.
Living things can cause erosion, too. For example,
ground squirrels tunnel through soil. The tunneling
allows water and air to move into the ground. This
continues the process of erosion.
72
Unit 6
6
Read and write two examples of landforms
produced by deposition.
Deposition
The rock and soil that erosion carries away must go
somewhere. The placing of pieces of Earth’s surface in
a new place is called deposition.
New islands can form as a result of deposition. This
happens when rivers carry rock and bits of soil to the
ocean. These particles build up over time and can form
islands just off the coast.
Wind can also cause deposition. Wind can blow
sand into mounds. These mounds are called sand dunes.
Landforms produced by deposition:
7
Read and match the columns.
Weathering, Erosion, and Soil
Soil is made up of tiny pieces of rock, air, water, and humus.
The tiny pieces of rock come from larger rocks that have
broken up. Rocks are broken up and moved about through
weathering and erosion. Small plants sprout in the rock and
eventually die. The remains of these plants break down and form
humus. Soil develops from different kinds of rocks and plants.
This is part of the reason soil is not alike everywhere in the world.
1. Weathering
moves weathered material.
2. Erosion
is formed partly by small rocks.
3. Soil
breaks down rocks.
Lesson 3 Check
Got it?
T hi nk !
How do plants help
to form soil?
60-Second Video
Unit 6 73
Let’s Investigate!
Materials
What can cause rock to crack?
plastic cup
with plaster
1.
Push the foil end of the
sponge into the plaster.
Keep the other end out.
Wait 1 day.
2.
On Day 2, pull the sponge
out. Observe how the
plaster has changed.
Record.
3.
Fill the foil with water.
Put the cup in a freezer.
Wait 1 day.
4.
On Day 3, observe how the plaster has changed.
Record.
sponge with foil
plastic cup
with water
Plaster Observations
Day 2
Day 3
74
Unit 6
Let’s Investigate! Lab
Unit 6
How do forces cause changes
on Earth’s surface?
Review
Lesson 1
What is the water cycle?
1
List the stages of the water cycle.
Lesson 2
How do we describe features of Earth’s surface?
2
3
Write one example of a slow change to Earth’s surface.
Write one example of a rapid change to Earth’s surface.
Lesson 3
What are weathering and erosion?
4
Compare weathering and erosion. Write one way
they are the same and one way they are different.
Same:
Different:
Got it? Quiz
Got it? Self Assessment
Unit 6 75
Unit
7
Earth and Our Universe
How do objects in space
affect one another?
I will learn
1
fall
nighttime
daytime
winter
ō
spring
summer
2
Why does the sun appear to rise in
the sky in the morning? Discuss with
a partner.
3
Why is the moon so bright in the
night sky? Discuss as a class.
76
what causes daytime,
nighttime, and the seasons.
ō what causes the phases
of the moon.
Look and label.
Unit 7
T hi nk !
Where are the
stars during
the day?
Lesson 1 . What are Earth’s patterns?
1
Read and write two details about Earth’s axis.
axis
Key Words
axis
ō rotation
ō revolution
ō seasons
ō shadow
ō
How Earth Moves
As you read this, you may not feel like you are
moving. But you are. Earth is always moving. One way
Earth moves is that it spins around its axis. Earth’s axis is
an imaginary line that runs between the North Pole and
the South Pole. Find Earth’s axis in the diagram. Notice
that the axis is not straight up and down. It is tilted.
If you could look down at the North Pole, you would
see that Earth turns in a counterclockwise direction. This
direction is opposite to the direction in which the hands
of a clock move. You could also say that Earth turns
from west to east.
Th in k!
If you were at the North Po
le,
would you see Earth’s axis?
Why or why not?
Let’s Explore! Lab
Unit 7 77
3
Read. What does Earth’s spinning cause? Complete the answers with a partner.
Day and Night
Seattle 6:00 A.M.
Earth’s spinning causes day and night. Earth makes
one complete spin on its axis, or rotation, every 24
hours. During this time, half of Earth faces the sun. That
half of Earth has day. The half of Earth that is not facing
the sun has night. As Earth spins, or rotates, a different
part of Earth turns to face the sun.
Earth’s spinning also causes changes in the sun’s
position in the sky. In the morning, the sun appears
to rise in the east. During the day, the sun seems
to move across the sky and then set in the west.
You might think the sun moves around Earth.
Actually, Earth is moving.
axis
Look at the diagram. When it is still nighttime
in Honolulu, Hawaii, the sun is rising in Seattle.
In Mexico City, it is daytime.
Honolulu 3:00 A.M.
78
Unit 7
I Will Know...
Mexico City 8:00 A.M.
5
Read and circle T (true) or F (false). With a partner, correct the false statements.
Revolution around the Sun
You know that Earth rotates on its axis. Earth also moves, or revolves, around the
sun. Earth makes one revolution when it makes one complete trip around the sun.
One revolution takes about one year. As Earth revolves around the sun, Earth’s tilted
axis always points in the same direction in space.
1. The sun moves around Earth.
T
/
F
2. It takes Earth about 365 days to revolve around the sun.
T
/
F
3. A revolution is one complete trip of the sun around Earth.
T
/
F
4. Earth’s axis points in different directions.
T
/
F
6
Draw an on the position of Earth where the northern half receives the most
direct sunlight.
June
Earth’s northern
half is tilted toward
the sun. It is summer
in the northern half
of Earth.
December
March
Earth’s northern half
is tilted away from
the sun. It is winter
in the northern half
of Earth.
sun
September
T hi nk !
How are a rotation
and a revolution
different?
Unit 7 79
7
Read and answer the two questions. Compare your answers with a partner.
Seasons
A year is divided into four seasons––spring, summer,
fall, and winter. The seasons are caused by the tilt of
Earth’s axis and the planet’s revolution around the sun.
As Earth moves around the sun, different parts of the
planet tilt toward the sun. Look at the position of Earth
in June on page 79. The northern half of Earth is tilted
toward the sun. The northern half receives more direct rays
of sunlight than the southern half and heats up more. It is
summer in the northern half and winter in the southern half.
Now look at Earth’s position in December. The
northern half of Earth is tilted away from the sun.
The northern half gets less sunlight and has colder
temperatures than the southern half. It is winter in the
northern half and summer in the southern half.
In March and September, neither end of Earth’s axis
points toward the sun. Both halves of Earth get about
the same amount of sunlight.
80
Unit 7
1. In September, the
northern United States gets
about 12 hours of daylight
each day. About how
many hours of daylight
do you think the northern
United States gets each
day in March?
2. What is the result of
the revolution and tilt
of Earth?
morning
8
Read and draw a small circle to show where
the sun would be in each picture.
Shadows during the Day
On a hot summer day, you might escape the heat
by standing in the shade of a tree. Did you know
you are standing in a shadow?
A shadow forms when an object blocks the light
that hits it. The shadow has about the same shape
as the object that blocks the light.
midday
The length and direction of shadows change
during the day. Find the shadows made by the tree
in the pictures. Notice that the morning shadow is
long. The shadow stretches in the opposite direction
from the sun in the eastern sky.
As the sun appears to move higher in the sky, the
shadow becomes shorter. Around midday, the sun is
at its highest point in the sky. The shadow is very short.
afternoon
As the sun continues moving across the sky, the
shadow becomes longer. Look at the length of the
shadow in the third picture. The afternoon shadow
stretches in a different direction than the morning
shadow did. As the sun moves toward the horizon
in the west, the shadow stretches toward the east.
Shadow Length during the Year
The length of a shadow changes during the year.
This is because the sun’s position in the sky changes
with the seasons. In the northern half of Earth, the sun
is higher in the sky in summer. The sun is lower in the
sky in winter. For that reason, the shadows at noon
are shorter in the summer and longer in the winter.
Lesson 1 Check
Got it?
60-Second Video
Unit 7
81
Lesson 2 . What is known about the moon?
Key Words
moon phase
ō new moon
ō full moon
ō telescope
ō crater
ō
moon
sun
Earth
Motions of the Moon
1
Read and write
a caption for the
illustration above.
2
Draw an on the full
moon. How does the
moon’s shape seem
to change? Discuss
as a class.
If you go outside on a clear night, you can usually see
the moon. The moon is Earth’s closest neighbor. You know
that Earth orbits the sun. But did you know that, as Earth
moves around the sun, the moon travels along with it?
The moon revolves around Earth while Earth revolves
around the sun. The moon takes about 27 days to
complete one revolution around Earth. The moon also
rotates on its axis about once every 27 days. Because
these two motions happen at the same rate, the same
side of the moon always faces Earth.
82
Unit 7
Explore My Planet!
Read and number the captions (1–4) according to the pictures of the moon phases.
3
1
2
new moon
4
4
first quarter phase
3
3
full moon phase
4
third quarter phase
1
2
Read. Why is the moon the brightest object in the night sky? Discuss with a partner.
Moon Phases
The moon is the brightest object in the night sky. But the moon does not make light.
It reflects light from the sun. When you see the moon shining, you are seeing reflected
sunlight.
Half of the moon is always lit by the sun. But the moon’s lit half cannot always be
seen from Earth. Every day, you can see different amounts of the lit half. These changes
are caused by the movements of Earth and the moon.
The shape the moon seems to have at a given time is called a moon phase. The
moon’s phases change in a cycle that repeats every 29 1/2 days. At first, no part of the
moon’s lit half is visible. This is called a new moon. During the next two weeks, more of
the moon’s lit half becomes visible. The full moon phase is when the moon looks like a
complete circle. During the weeks after the full moon, you see less and less of the moon’s
lit half. Then there is another new moon.
5
Why is the moon harder to see during the day? Discuss as a class.
I Will Know...
Unit 7 83
6
Read the caption and look at the diagram. Draw an on the moon
phase where the sunlit side does not face Earth.
first quarter
Half of the moon is always lit
by the sun. A person standing
on Earth sees different parts
of the sunlit half as the moon
moves in its orbit.
new moon
full moon
third quarter
7
Read and underline two uses of a telescope and one different use of the
Hubble Space Telescope.
Telescopes
You can use tools to help you see the moon
better. One tool is a telescope. A telescope
makes objects that are far away look like they
are nearer and larger. You can use a
telescope to see more details of the light and
dark areas on the moon’s surface.
People have used spacecraft to put telescopes
in outer space. For example, the Hubble Space
Telescope began orbiting Earth in 1990.
Scientists use it to observe and take pictures of
planets, stars, moons, and other space objects.
84
Unit 7
8
Read and look at the picture of the moon. Is the area in the picture part of the
highlands? Discuss with a partner.
Characteristics of the Moon
The moon is the closest natural object to
Earth. It is 384,000 kilometers (239,000
miles) away. The moon is smaller and has
much less mass than Earth. In fact, Earth’s
volume is 49 times greater than the
moon’s. Earth has 81 times more mass.
The moon’s surface has many craters.
A crater is a bowl-shaped hole on the
surface of an object in space. Most of the
moon’s craters formed when large objects,
such as asteroids, smashed into the moon.
When you look at the moon, you see that there
are light and dark areas on it. The light areas are
mountains and highlands. There are many craters in
these areas. The dark parts of the moon are flat areas
with some craters. Billions of years ago, volcanoes
erupted on the moon. Lava from these eruptions spread
out and hardened. It formed the dark areas.
The temperature on the moon’s surface varies. During
the day, the temperature can rise as high as 127 °C
(260 °F). At night, it can get as cold as -173 °C (-280 °F).
Lesson 2 Check
Got it?
Air Pollution
Every year, air pollution
makes it harder to
see the moon and the
stars in the night sky.
Pollution is released
into the air when
people burn fuels to
make electricity or to
run cars. Make a list
of things you and your
family can do to help
reduce air pollution.
60-Second Video
Unit 7
85
Let’s Investigate!
Materials
Why do you see phases of the moon?
scissors
black paper
box with holes
1. Make a model of the night sky. Glue black paper
to the inside of the box and lid.
2. Poke holes in the paper where there are holes in
the box. Use crayons to label the small holes.
3. Push the flashlight into the large hole in the side.
Tape it in place.
tape and glue
4. Attach the thread to the ball with the tack.
Tape the thread in the center of the lid.
5. Put the lid on the box. Turn on the flashlight. Look
through each hole. Record your observations
in your notebook. Draw the four moon phases
you observe through every hole and write
their names.
flashlight
table tennis ball, black
thread, thumbtack
B
C
black
and white
crayons
A
metric ruler
D
about 4 cm
86
Unit 7
Let’s Investigate! Lab
Unit 7
How do objects in space
affect one another?
Review
Lesson 1
What are Earth’s patterns?
Match each word with its description.
1. axis
2. rotation
3. revolution
1
Answer the questions.
1. How long does it take for Earth to make one
2
2.
Lesson 2
What is known about the moon?
3
The shape the moon appears to have at a given
time is called a
.
c. orbit
d. revolution
Got it? Quiz
Got it? Self Assessment
Unit 7 87
Unit
8
1
Energy and Its Forms
How can energy change?
I will learn
Look and label.
about different forms of
energy.
ō what heat and energy are.
ō
recorder
smartphone
light bulb
candles
sun
solar panel
2
3
88
What kinds of energy does each
object in the pictures represent?
Discuss with a partner.
Where does the energy your
body uses come from? Discuss
as a class.
Unit 8
T hi nk !
How does this
runner use
energy?
Lesson 1 . What are some forms of energy?
1
Read and circle any place you see energy in this photo.
2
Read and complete the graphic organizer. Write
the effects of the sun’s energy. Then compare your
answers with a partner.
Key Words
energy
ō electrical energy
ō mechanical energy
ō sound energy
ō potential energy
ō kinetic energy
ō
Energy
The ability to do work or to cause change is called
energy. Work is done when a force moves an object.
The sun is the main source of energy on Earth’s surface.
Energy from the sun causes many effects. Energy from the
sun makes Earth a place where we can live. Light from
the sun helps plants grow. Energy from the sun causes
winds to blow and water to move through the water cycle.
T hi nk !
How does the
sun’s energy
affect humans?
Effects
Cause
Explore My Planet!
Unit 8 89
3
Read and look at the pictures. With a partner, list five things that use
electrical energy.
Energy at Home
You use many forms of energy every day in your home. The living and nonliving
things in the home below use many forms of energy.
Electrical energy is the
movement of electric charges.
It powers things that use
electricity, such as a lamp.
Things that use electrical
energy:
1. Possible answers:
2. television, electric guitar,
3. air conditioner, lam,
4.smartphone, refrigerator,
5.microwave, toaster, clock,
Light energy is energy
we can see. Light energy
comes through windows
and brightens rooms.
Heat is the transfer of
energy from a warmer
object to a colder object.
Heat is used to cook food
in the kitchen.
4
90
Read and draw an on three things that
use heat energy.
Unit 8
I Will Know...
5
Read and look at the four rooms in the house.
Circle five things that use mechanical energy.
6
Mechanical energy is energy that motion or position
gives to an object. You use mechanical energy every
time you move or lift an object or use a machine with
moving parts.
Sound energy is energy we can hear. Musical
instruments produce sound energy.
Mark () the things
that produce sound
energy.
plant
lamp
clock
guitar
bed
recorder
cat
towel
7
With a partner, list
some common forms
of energy used in
your school.
8
Why is a simple
toothbrush considered
a machine? Discuss
as a class and write
the answer.
Because it uses mechanical
energy to do work.
Unit 8 91
9
Read and answer the questions with a partner.
Stored Energy
Energy can be stored. As you stand ready to jump,
run, or snowboard, your body has stored energy.
Stored energy makes movement possible. Stored
energy is potential energy. Potential energy changes
into another kind of energy if you use it to do work
or cause a change.
A raised object has potential energy due to gravity.
For example, the snowboarder at the top of the hill
in the photo below has potential energy because of
his high position. Potential energy is also gained from
stretching or compressing objects. For example, you can
stretch or compress a spring to store potential energy.
The stored energy in food, fuels, and batteries is
chemical energy. Stored chemical energy can change
into a form that can do work. For example, the stored
energy in food is released to help you move. It can
also keep your body warm.
92 Unit 8
92 Unit 8
1. What kind of potential
energy do you put
inside your body in
order to live?
2. How do you use the
stored chemical energy
in batteries?
3. How do people use the
stored chemical energy
in fuels?
11
Read and underline the words that tell you about
kinetic energy.
Energy of Motion
Potential energy can change to kinetic energy, or
the energy of motion. A car moves when the chemical
energy stored in gasoline changes to kinetic energy.
Potential energy changes to kinetic energy when you
release a stretched spring. The potential energy the
snowboarder has at the top of the hill in the photos
changes to kinetic energy as he moves down the hill.
He moves down the hill because gravity pulls him.
Energy can be used to lift objects. When a
snowboarder carries a snowboard to the top of a hill,
he and the snowboard gain potential energy. They now have the potential to slide
to the bottom of the hill. At the bottom of the hill, the snowboarder may have
enough kinetic energy to lift him and his snowboard to the top of the next hill.
12
Read the paragraph and circle with different colors one cause and one effect.
How Energy Travels
Energy can travel from one place to another. Suppose
a moving object strikes another object. Some kinetic
energy passes to the second object. Have you ever
gone bowling? When the bowling ball hits the group
of pins, the ball slows down and the pins begin
moving. Before hitting the pins, the bowling ball has
all of the kinetic energy. The pins have no kinetic
energy. When the ball hits the pins, some kinetic
energy transfers to the pins. Heat is also produced,
which causes some energy to be lost. The total amount
of energy does not change.
Unit 8 93
13
Read and complete the sentences with words from the box.
Then check your answers with a partner.
Using Energy
Sometimes people use machines to change forms of energy. You
use kinetic energy to turn on a light switch, a common machine.
When the light switch is turned on, electrical energy changes to
light energy. A cable car, another machine, changes potential energy to kinetic energy.
An electric toothbrush is another machine. It has an electric cord that plugs into an
outlet. Electrical energy is stored as chemical energy in the battery of the toothbrush.
The chemical energy changes back to electrical energy when the toothbrush is turned
on. The electrical energy then changes to kinetic energy as the toothbrush moves.
Energy does not change completely from one form to another. Energy does not go
away, either. Some energy always produces heat. After you turn on a light bulb, it
becomes warm. This is because some of the energy produces heat.
chemical
potential
kinetic
light
1. When we turn on a lamp, electrical energy changes
lht
energy.
to
2. When a cable car moves,
energy transforms into kinetic energy.
3. When we turn on an electric toothbrush,
energy in its battery changes to electrical energy.
4. When the electric toothbrush moves, electrical energy
kinetic
changes to
energy.
T hi nk !
cable car
How does the
cable car gain
potential energy?
94
Unit 8
Lesson 1 Check
Got it?
60-Second Video
Lesson 2 . What are heat and light energy?
1
Read and circle T (true) or F (false). Then correct the false statements with a partner.
Thermal Energy and Heat
Matter is made of very small moving particles. Each
particle of matter moves because it has energy. The
energy of moving particles is called thermal energy.
Thermal energy is the kinetic energy and potential
energy of particles in matter. Energy from the sun makes
the particles in objects move faster. The objects become
warmer. That is why sunlight feels warm on your skin.
When the sun’s energy no longer reaches the matter, its
particles slow down and the matter cools. That is why
you feel cooler when you are in the shade.
Key Words
matter
ō particles
ō thermal energy
ō spacecraft
ō solar panel
ō generator
ō
Heat is the transfer of energy from one place to
another. Heat can take the form of thermal energy
traveling from warmer objects to cooler objects. When
you place a metal spoon into a pot of cooking food, heat
travels from the warmer pot through the cooler spoon. In
a short time, the top of the spoon will feel warm.
1. Thermal energy is produced when the particles of matter do not move.
T/F
2. The sun’s energy makes the particles in objects move faster.
T/F
3. Objects exposed to the sun’s energy get cooler.
T/F
4. Heat is produced when energy stays in one place.
T/F
Th in k!
What causes the
candles to melt?
Explore My Planet!
Unit 8 95
2
Read and underline three ways people can
heat their homes.
Heat and Light
When energy changes form, one result is
heat. For example, heat is produced when you
rub two objects together. You can investigate
heat by rubbing your hands together. Your hands
warm up because kinetic energy is transformed
into thermal energy.
Energy heats your home. Some people heat their homes
with natural gas. Some people use electricity. Other people
use solar panels that collect energy from the sun.
When energy changes form, some energy is always
given off in the form of heat. Think about light. Energy
changes form when light is produced. This means that
sources of light are also sources of heat.
Burning is a chemical change that can produce
light and heat. For example, candles, campfires, and
matches give off light that helps heat the space around
them as they burn.
96
Unit 8
I Will Know...
5
Read and circle the word that correctly completes
each sentence.
Electricity can also be a source of light and heat.
Electricity makes the wire in a light bulb get so hot that it
gives off light. Bulbs in heat lamps can be used to keep
food warm.
Making Electricity from Light
You know your home needs electricity. How do you
think a spacecraft gets electricity?
While in orbit, a spacecraft spends part of its time in
sunlight. Solar panels gather light and change it to the
electricity used to run the ship. The spacecraft spends
the rest of its time in the shadow of Earth, where there is
no sunlight. How does it get electricity then?
Spacecraft have generators that
make electricity. One kind uses a heavy
wheel called a flywheel. While in sunlight, motors make
this wheel spin quickly. The kinetic energy from the spinning
generates electricity while the spacecraft is in the dark.
1. Sunlight / Solar panels get light from the sun and transform it into electricity.
2. Flywheels / Spacecraft are generators that produce electricity.
3. Generators / Solar panels produce energy when there is no sunlight.
Lesson 2 Check
Got it?
60-Second Video
Unit 8 97
Let’s Investigate!
Materials
He^gVaEViiZ
gc
How does heat cause motion?
Copyright ©
by Pearson Education,
Inc., or its affiliates.
All rights reserved.
1. Cut out the spiral.
scissors
Spiral Pattern
tape
lamp
2. Tape one end of the string to the middle of
the spiral.
3. Predict what will happen if you hold the spiral
over the lamp before the bulb is turned on. Record.
4. Predict what will happen if the bulb is turned on.
Record.
5. Test your predictions. Record your observations.
Motion of Spiral
Predictions
Lamp
off
Lamp
on
98
Unit 8
Let’s Investigate! Lab
Observations
string
Unit 8
How can energy change?
Review
Lesson 1
What are some forms of energy?
1
2
Match the sentence halves.
a) Electrical energy
is used when objects are moved or lifted.
b) Mechanical energy
is produced by musical instruments.
c) Sound energy
powers things that use electricity.
List three objects in your home that use or produce each form of energy below.
Electrical
Mechanical
Sound
Lesson 2
What are heat and light energy?
3
Complete the sentences with the words from the box.
light
sun
heat
a) Rubbing your hands together produces
b) Candles and matches give off
.
c) Solar panels collect energy from the
4
.
and
.
Write two ways heat and light energy can affect matter.
Got it? Quiz
Got it? Self Assessment
Unit 8 99
Unit
9
1
Forces and Motion
What forces cause motion?
I will learn
Look and label.
what motion is.
ō how force affects motion.
ō what gravity is.
ō
shopping cart
slide
magnet
kite
crane
roller coaster
2
Which of the objects above have
you used? Discuss with a partner.
3
How can a crane with a magnet
be used? Discuss as a class.
T hi nk !
How do you know
the biker is
moving, and not
the trees?
100
Unit 9
Lesson 1 . What is motion?
1
Key Words
Read both paragraphs and look at the picture on
the right. With a partner, discuss the answer to the
question below the picture.
position
ō motion
ō speed
ō
When Objects Move
Look at the picture of the children playing. How would
you describe the position of the boy? Position is an
object’s location, or where something is. You might say
the boy’s position is on the ladder or beside the slide.
Now look at the girl sliding down the slide. The girl
is in motion. Motion is a change in the position of
an object. Motion describes the girl’s movement from
the top of the slide toward the bottom.
2
Read. With a partner, describe the position of the
yellow race car in the picture.
An Object’s Position
The position of an object often depends on how a
person looks at it. Suppose you wanted to tell a friend
about a car in the picture. How would you describe its position? You could use numbers
to describe distances. You could also use position words, such as in front of, behind, left,
right, and beside. The words you use might change if you were riding in the car.
You could also draw a map. A map models the position of objects in relation to
each other.
T hi nk !
How can a map help
you describe the
location of
an object?
Explore My Planet!
Unit 9 101
3
Read and look at the picture. Answer the three questions with a partner.
Positions of Moving Objects
Objects on a map are fixed in place. How do you describe the position of moving
objects? The cars and the boat in the picture are in motion. The way you describe
their position may change depending on the position and motion of other objects.
First, the boat will be in front of the car. Then, it will be behind the car.
102 102
Unit 9
I Will Know...
4
Read and underline the main idea of the first paragraph.
How Fast Objects Move
How can you describe how fast objects move?
You can say their speed. Speed is the rate
at which, or how fast, an object changes
its position. A jet plane’s speed is about
900 kilometers per hour. Your speed on a
bike might be about 15 kilometers per hour.
The jet plane changes position faster than
your bike, so its speed is greater.
T hi nk !
How can a moving
object increase or
decrease its
speed?
Constant Speed
Sometimes moving objects move at a constant
speed. A plane that flies steadily at 900 kilometers
per hour is moving at a constant speed. The plane
does not change how fast it moves.
Variable Speed
A roller coaster would not be fun if it
moved at a constant speed. The thrill of the
ride comes from slowly climbing up and
then quickly moving down the steep track.
The roller coaster moves at a variable
speed. It changes speed as it moves.
5
Write three examples of objects that
move at a variable speed.
1.
2.
3.
Lesson 1 Check
Got it?
60-Second Video
Unit 9 103
Key Words
Lesson 2 . How does force affect motion?
Read and complete the sentences in the graphic
organizer. Then check your answers with a partner.
1
force
ō friction
ō magnetism
ō iron
ō magnet
ō steel
ō
Causes of Motion
Crack! A baseball player hits a ball. The bat pushes
against the ball. The bat has all the power of the
player’s swing. A force causes the motion, speed,
and direction of the ball to change. A force is a push
or a pull.
Most of the forces you use are contact forces. When
you hit a baseball with a bat, the bat’s force changes the
speed and direction of the ball. If the bat does not make
contact with the ball, these changes cannot occur.
Fact
Fact
Fact
104
Unit 9
Conclusion
Let’s Explore! Lab
2
Read and look at the pictures below the text. Circle the picture where the man is
pushing more mass. Then put an on the picture where he must use more force
to change motion.
Effects of Mass and Friction
A force can change an object’s position or the
direction of its motion. A push by the man can cause the
shopping cart to start moving. If he then pushes to the
right, the moving cart will change direction to the right.
How much an object changes its direction and speed
depends on how much force is used. A large force will
cause a greater change in motion than a smaller force.
The cart will go faster if the man pushes harder.
How an object moves also depends on its mass. When
the man starts shopping, his cart is empty. He does not
need much force to push it. As the man shops, he puts
objects in the cart. Each time he does, the mass gets
larger. The man must then use more force to push the cart.
While the man’s grocery cart moves down the aisle, its wheels rub against the floor.
This causes friction. Friction is a contact force that opposes the motion of an object.
Friction can cause a moving object to slow down or to stop.
The amount of friction between two objects depends on their surfaces. Pushing a
grocery cart over smooth tiles in a store is pretty easy. You need more force to push a cart
across an asphalt parking lot. The smooth tile produces less friction than the asphalt does.
I Will Know...
Unit 9 105
4
Read and underline two forces that act on the kite.
Motion and Combined Forces
weight
wind
the girl pulls
the string
As a kite flies through the air, it dips, and it dives. What
forces act on the kite? The force of the wind pushes it up.
Weight is one of the forces pulling it down. The girl also
pulls down on the string. An object’s motion depends on
all the forces that act together.
Balanced Forces
Sometimes a kite hangs in the air. It is almost
motionless. This is because the forces acting on the kite
balance each other. Forces that work together and make
no change in motion are called balanced forces.
You can see balanced forces all around you. Think of
two strong football players pushing against each other.
If they each push with the same force, but in opposite
directions, neither player moves.
Unbalanced Forces
If the forces acting on an object are not balanced, the
motion of the object will change.
6
106
Read the last
paragraph again
and look at the
picture on the right.
Which way do
you think the rope
is moving? Why?
Discuss as a class.
Unit 9
You might compare the forces acting on an object
to a game of tug-of-war. In tug-of-war, two teams pull a
rope in opposite directions. If the forces are equal, the
rope does not move. To win, one team must pull with
greater force than the other team. The rope will then
move in the direction of the greater pull.
Less force
More force
7
Read and circle T (true) or F (false). Correct the false
statements with a partner.
Magnetism
A noncontact force can push or pull an object without touching
it. Magnetism is a noncontact force that pulls on, or attracts, metal
objects containing iron.
If you place some metal paper clips near a magnet, the
magnet will pull the paper clips toward it. A very strong
magnet might pull a steel paper clip from halfway across
your desk. Steel is a metal that has iron in it. Magnets
do not attract wood, plastic, paper, or other objects
that do not contain iron.
Magnets work because they have a magnetic
field around them. The field is strongest near
the magnet’s poles. Each magnet has a
north pole and a south pole. The north
pole of one magnet will attract the
south pole of another magnet.
Poles that are the same will push
away from each other.
Th in k!
Why is magnetism
a noncontact
force?
Lesson 2 Check
Got it?
60-Second Video
Unit 9 107
Key Words
Lesson 3 . What is gravity?
gravity
ō weight
ō matter
ō mass
ō
T hi nk !
Why do skydivers
fall back to Earth?
1
Read and complete the sentences with the words from the box.
Law of Gravity
There are different forces acting on people all of the time.
A force is any push or pull. One kind of force is a noncontact
force. A noncontact force is a push or pull that affects an
object without touching it. Gravity is a noncontact force that
pulls objects toward one another. The law of gravity states
that all objects are pulled toward one another by gravity. Skydivers and water from
this fountain are pulled toward Earth by gravity. Without gravity, they would float
away. Gravity pulls you and everything else on Earth toward Earth’s center.
center
gravity
force
noncontact
is a push or a pull on people and objects.
1. A
2. Gravity is a kind of
force.
3. Skydivers would float away without
.
4. Gravity pulls people and objects toward Earth’s
108
Unit 9
Let’s Explore! Lab
I Will Know...
.
2
Read and complete the sentences with a partner.
Gravity and Weight
The pull of gravity on an object gives an object
its weight. An object’s weight depends on where it
is. When the pull of gravity is weaker, the object’s
weight is less. For example, the moon has less gravity
than Earth. So, you weigh less on the moon. The pull of
gravity is also less the farther you are from Earth’s center.
So, you weigh less on a mountaintop than in a valley.
An object’s weight also depends on the amount of
matter in an object. Objects with more matter have
more mass. So, the pull of gravity is greater on an
object with more mass. For example, the pull of gravity
is greater on an elephant than on an apple. Even if
the pull of gravity changes, the object’s mass stays
the same. Your mass on Earth and on the moon is the
same, but your weight is different.
Gravity is a force that can be overcome. For example,
when you toss a ball in the air, the ball overcomes gravity
for a few moments. Then it falls back to Earth. If your push
is stronger than the pull of gravity, the ball will go up.
Gravity pulls the ball back down. It is easier to overcome
gravity with a light object than with a heavy object.
1. You are heavier on Earth than on the moon
because
.
2. The pull of gravity is greater on an elephant than on
an apple because the elephant has more mass
.
3. Gravity can be overcome for a few moments when
.
Lesson 2 Check
Got it?
60-Second Video
Unit 9 109
Materials
Let’s Investigate!
books
How can you describe motion?
1.
Measure 2 meters from a wall and place one
end of the chute there.
2.
Place 2 books under the other end of the chute.
3.
Release the ball at the top of the chute. Start
timing when the ball reaches the floor.
4.
Record the time when the ball hits the wall in
the chart below.
5.
Stop the timer when the ball comes back to the
bottom of the chute. Record in the chart below.
6.
Stack 4 books and repeat steps 2 to 5.
meterstick
ball
timer
chutes
2m
Ball Movement Results
Time (seconds)
Number
of Books
From Bottom of
Chute to Wall
(Time A)
From Bottom of Chute
to Wall and Back
(Time B)
2 books
4 books
110
Unit 9
Let’s Investigate! Lab
From Wall to
Bottom of Chute
(Time C = Time B – Time A)
Unit 9
What forces cause motion?
Review
Lesson 1
What is motion?
.
.
Motion is
Lesson 2
How does force affect motion?
2
Read the question and underline the correct answer.
How does the amount of force affect motion?
a. A smaller force causes a bigger change in motion.
b. A larger force causes a bigger change in motion.
Lesson 3
What is gravity?
3
Match each word with its definition.
1. force
A force that pulls objects
toward Earth.
2. weight
The amount of matter
an object has.
3. gravity
A push or a pull.
4. mass
The amount of the pull
of gravity on an object.
Got it? Quiz
Got it? Self Assessment
Unit 9 111