Chapter 1

Chapter 2

Chapter 3

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CHAPTER

1

Adaptations
in Land
Environments

What are adaptations and how
do they help living things survive?

20


Lesson 1

Living Things and
Their Needs
PAGE

24

Lesson 2

Life in the Desert

PAGE

36

Lesson 3

Life in the Grassland

PAGE

46

Lesson 4

Life in the Forest


PAGE

56

Lesson 5

Life in the
Arctic Tundra
PAGE

68

3 LS 3. Adaptations in physical structure or behavior
may improve an organism’s chance for survival.

21


Literature
Poem
ELA R 3.2.3.
Demonstrate
comprehension by identifying
answers in the text.
ELA W 3.1.1. Create a single
paragraph: a. Develop a topic
sentence. b. Include simple
supporting facts and details.


giant sequoias

22


from Iguanas

in the Snow

by Francisco X. Alarcón

These are the great-greatgreat-great-grandparents
of the Sierra Nevada

it takes my whole
family holding hands
for us to give a hug

their many scars tell
of the storms and fires
they have survived

to the tallest
and oldest tree
in this grove

every year without fail
their huge trunks
add another ring
thick in a wet year

with plentiful rains—
thin in a dry one

Write About It
Response to Literature This poem tells us that sequoia
trees can survive forest fires. What else have you
learned about them from this poem? Write a paragraph
about sequoia trees. Think about what you already
know about trees and use details from the poem.

-Journal Write about it online @ www.macmillanmh.com
23


Lesson 1

Living Things
and Their Needs
Living things can be found all over
Earth. How do living things get
what they need to survive?

24
ENGAGE

Building block lesson for 3 LS 3.a. Students know plants and animals have
structures that serve different functions in growth, survival, and reproduction.
3 LS 3.b. Students know examples of diverse life forms in different environments,
such as oceans, deserts, tundra, forests, grasslands, and wetlands.



What do plants need to live?

Materials

Form a Hypothesis
Do plants need light? Do they need water?
Write a hypothesis.

Test Your Hypothesis

4 identical plants

Label four identical plants as shown.
Light and
Water

Light and
No Water

No Light
and Water

No Light and
No Water

measuring cup
and water
Step


Observe How do the plants look?
Record your observations in a chart.
Put the plants labeled No Light in a dark
place. Put the plants labeled Light in
a sunny place. Water the plants labeled
Water every few days.

Predict What do you think will happen
to each plant?

Record Data Look at the plants every
few days. Record your observations
in your chart.

Plants
Light
and Water
Light and
No Water
No Light
and Water
No Light and
No Water

Day Day Day Day
1 4 8 12

Draw Conclusions
Analyze Data Which plant grew the most after
two weeks? Which plant looks the healthiest?

What do plants need to live?

Explore

More

Experiment What else do plants need to live?
How could you find out? Make a plan and try it.

3 IE 5.e. Collect data in an
investigation and analyze
those data to develop a
logical conclusion.

25
EXPLORE


C Main Idea

3 LS 3.a
3 LS 3.b

Living things get what
they need from their
environment.

C Vocabulary
environment , p. 26
biome , p. 26

climate , p. 27

Deserts are biomes that have dry climates
and sandy soil. Deserts can be hot or cold.

soil , p. 27
humus , p. 27
structure , p. 29
shelter , p. 30
adaptation , p. 32

-Glossary
@

www.macmillanmh.com

C Reading Skill
Draw Conclusions
BSfb1ZcSa

1]\QZcaW]\a

C Technology
Explore biomes with
the Secret Agents.

26
EXPLAIN

Where do living things live?

Look outside. Do you see any living
things? You probably do. Living things live
almost everywhere on Earth. They live in any
environment (en•VIGH•ruhn•muhnt) where
they can meet their needs. An environment
is everything that surrounds a living thing.
Environments are made up of both living
and nonliving things. Plants and animals
are living things. Water, air, and sunlight are
nonliving things.

Biomes
Scientists group environments with similar
traits into biomes (BIGH•ohmz). A biome is an
area of land or water that has certain kinds of
living and nonliving things. Deserts, forests,
and grasslands are examples of biomes.


Grasslands are biomes
that have mainly grasses.

Each biome has a certain kind of climate
(KLIGH•mit) . Climate describes the typical weather
conditions of an area over time. Some biomes are
cold and dry for most of the year. Some are warm
and wet. A biome’s climate affects which living
things can survive there.
Each biome also has a certain type of soil. Soil
is a substance that covers the ground. It is made

of broken-down rocks and humus (HYEW•muhs).
Humus is broken-down plant and animal material.
Humus adds nutrients to the soil. It soaks up
rainwater and keeps the ground moist.
Quick Check
Draw Conclusions Do all deserts have similar

kinds of living things?
Critical Thinking What are some of the living

things in a city environment?

27
EXPLAIN


How do plants get what they need?
From the tallest redwood tree to the smallest pansy,
most plants have the same basic needs. They need water,
sunlight, energy from food, and carbon dioxide. Carbon
dioxide is a gas found in air. Plants need nutrients, too.
Nutrients are substances that help living things grow
and stay healthy. Plants must get all these things
from their environment in order to survive, but they
make their own food.
Stems carry food
and water throughout
the plant. Stems also
keep a plant upright so
leaves can get sunlight.


Roots take in water
and nutrients from
the soil. They also
keep a plant in place.

28
EXPLAIN


Plants have structures that
help them get or make what they
need. A structure is a part of a
living thing. Most plants have
roots, stems, and leaves. Many
plants also have flowers, fruits,
and seeds. These parts help
plants live, grow, and reproduce.
Reproduce means to make new
plants like themselves.
Quick Check
Draw Conclusions Why are

roots important to plants?

Observe Plant Parts
Get two plants to observe.
Observe Look at the parts of
each plant. Does each plant
have roots? How about stems

and leaves?
Record Data Use pictures and
words in a chart to describe
each plant’s parts.
Compare How are the parts
of these plants alike? How are
they different?

Critical Thinking Why don’t

plants need to eat?
basil

Leaves take in
carbon dioxide
from the air. They
use energy from
the Sun to change
carbon dioxide
and water into
food for the plant.

carrot

Read a Diagram
How do leaves help plants get what they need?
Clue: Bold words can help you find information.

29
EXPLAIN



How do animals get what they need?
Like plants, all animals have the same basic
needs. Animals need water, energy from food, and
oxygen. Oxygen is a gas found in air and water.
Some animals need shelter, too. A shelter is
a place in which an animal can stay safe.
Animals have structures that help them meet their
needs in their environment. Body parts, such as legs,
wings, and beaks are examples of animal structures.

Getting Food, Water, and Oxygen
Animals cannot make their own food the way
plants can. Instead, they must eat plants or other
animals. Legs, fins, and wings help animals move to
find food. Beaks and tongues help animals catch and
swallow food. They help animals drink water, too.

A lion’s rough
tongue helps
it get water. C

30
EXPLAIN

A Some birds
use nests for
shelter.



gills
A Gills help fish get oxygen.

Structures help animals breathe.
Animals breathe to get oxygen.
Many animals breathe with lungs.
Lungs take in oxygen from the air.
Fish breathe by pushing water
through their gills. Gills take in
oxygen from water.

Finding Shelter and Staying Safe
Some animals use trees or other
plants for shelter. Other animals build
their own shelters. Birds, for example,
build nests as shelters for their young.
Birds use their beaks and feet to gather
materials and build their nests.
Some animals have structures that
help them stay safe. A kangaroo’s
pouch helps young kangaroos stay
safe. A porcupine’s sharp quills help
it stay safe from other animals.

A A young kangaroo develops
in its mother’s pouch. There
it stays safe.

Quick Check

Draw Conclusions Why are

legs, fins, and wings important
to some animals?
Critical Thinking How might

the shape of a bird’s beak
affect what it eats?
31
EXPLAIN


What helps living things survive in
their environment?
Living things live in the environment that meets
their needs. Redwoods grow along the California coast.
Here the cool, damp climate and rich soil are just right
for them to grow. Cactuses grow well in Southern
California. Here the warm, dry climate and sandy soil
are just right for them to grow.
Adaptations (ad•uhp•TAY•shuhns) help living things
survive in their environment. An adaptation is a special
feature or behavior that helps a living thing survive. In
the next lessons, you will learn about some adaptations
that help living things survive in different environments.
Quick Check
Draw Conclusions Why can’t a cactus

grow where redwoods grow?
Critical Thinking Are a bear’s sharp


teeth an adaptation?
A bear’s claws are an adaptation
that help it catch fish.

32
EXPLAIN


Summarize the Main Idea
Living things live
in different kinds
of environments.

Think, Talk, and Write
Main Idea How do living things
get what they need from their
environments?

(pp. 26–27)

Vocabulary What is climate?
Plants and animals
have structures that
help them get what
they need.
(pp. 28–31)

Draw Conclusions Some soil has
very little humus. Would this kind of

soil soak up a lot of water or a little?
BSfb1ZcSa

1]\QZcaW]\a

Adaptations help
living things survive.
(p. 32)

Critical Thinking How are an
animal’s needs similar to a plant’s
needs? How are they different?

Make a
Study Guide
Make a three-tab
book. Use it to
summarize what
you learned.

Writing Link
Write a Paragraph
How do your moving parts help you
survive? Make a chart. In one column
list your moving parts. In the second
column tell how each helps you. Use
your chart to write a paragraph.

Test Practice How are biomes
grouped?

A by their size
B by their living and nonliving things
C by their structures
D by the height of the trees

Math Link
Make a Bar Graph
List ten plants that live near your
school. Then group the plants into
categories, such as grasses or trees.
Make a graph to show how many of
each category live near your school.

-Review Summaries and quizzes online @ www.macmillanmh.com

33
EVALUATE


Compare and Classify
Earth is a big place. Millions of living things find
homes in many different environments. With so many
living things and so many environments, what can
scientists do to understand life in our world? One
thing they do is compare and classify living things
and their environments.

Learn It
When you compare, you look for ways that things are
similar or different from each other. When you classify,

you put things into groups that are alike. Comparing and
classifying are useful tools for organizing and analyzing things.
It is easier to study a few groups of things that are alike than
millions of individual things.

Try It
You learned that scientists compare and classify Earth’s
environments. They compare and classify animals, too. Can you?
C To start, observe the animals shown on page 35. Look
for things they have in common.
C Then use their similarities and differences to group
the animals. What trait can you use for grouping
the animals? Let’s try wings. Which animals have
wings? Which animals do not? Make a chart to
show your groups.

wings

no wings
rhea

34
EXTEND

3 IE 5.e. Collect data in an investigation and analyze those data to develop a
logical conclusion.


Apply It
Compare and classify these animals using a different rule.


fish

eagle

frog

dog

chameleon

butterfly

bear

wild sheep

snake

squirrel

tiger

dragonfly

35
EXTEND


Lesson 2


Life in the
Desert

Death Valley is North America’s driest
desert. Less than two inches of rain fall
here in an entire year! What adaptations
help plants and animals survive in such a
dry place?

36
ENGAGE

3 LS 3.a. Students know plants and animals have structures that serve different
functions in growth, survival, and reproduction. • 3 LS 3.b. Students know examples
of diverse life forms in different environments, such as oceans, deserts, tundra,
forests, grasslands, and wetlands.


What adaptations help plants
survive in a desert?

Materials

Make a Prediction
hand lens

Why can some plants live in dry environments?
How do special structures help them survive?
Write a prediction.


Test Your Prediction
Observe Use a hand lens to observe each

two plants

plant. What structures do they have? What are
their leaves like? What are their stems like?

Record Data Make a chart to record your
observations. Use words and pictures.

scissors

Observe Cut a leaf from each plant in half.
Use a hand lens to look at the leaves. What
are the leaves like inside?

Step

Draw Conclusions
Compare How are the plants alike?
How are they different?

Infer What special structures help
the desert plant survive in its hot, dry
environment?

Explore


More

Step

Experiment Put a leaf from each plant on the
windowsill. How do the leaves change?
3 IE 5.e. Collect data in an investigation and analyze
those data to develop a logical conclusion.

37
EXPLORE


What is a desert?
C Main Idea

3 LS 3.a
3 LS 3.b

Deserts have dry
climates and sandy
soil. Desert plants
and animals have
adaptations that help
them survive.

C Vocabulary
desert , p. 38
nocturnal , p. 42
camouflage , p. 42


-Glossary
@

www.macmillanmh.com

C Reading Skill
Compare and Contrast
2WTTS`S\b

/ZWYS

2WTTS`S\b

Saguaro National
Park is in the
Sonoran Desert. C

38
EXPLAIN

A wave of heat blasts your body. You
take a deep breath and dry air stings
your nose. Dust from the sandy ground
covers your shoes. You are in the Sonoran
Desert. This is one of the largest deserts
in North America.
A desert is a biome that has a
dry climate. Less than 25 centimeters
(10 inches) of rain falls in a desert each

year. Several centimeters of rain may fall
all at once within a few days. Then for
months there is no rain at all.


Temperatures in a desert vary widely between
day and night. During the day, the Sun’s heat warms
the land and air. After the Sun sets, the temperature
drops quickly. The desert is much cooler at night than
in the day.
The soil in a desert is mostly sand. There is little
humus to soak up rain water. Rain water trickles
down through the desert sand. It goes deeper than
most plants’ roots can reach.
Quick Check
Compare and Contrast How do

a desert’s daytime and nighttime
temperatures compare?
Critical Thinking What are three

key features that describe deserts?

desert biomes

39
EXPLAIN


What adaptations help desert plants?

Some plants can grow in deserts. Other plants cannot.
Plants that grow in deserts have adaptations that help
them survive with little water. Special roots help them take
in water. Special leaves and stems help them store water.
Spines and thorns protect them from thirsty animals.
The diagram below shows some of these adaptations.

Adaptations of Desert Plants

mesquite tree

Small leaves
help conserve
water.

saguaro
cactus

Spines help
protect a cactus
from animals. They
also collect water.

Waxy skin
helps seal
in water.
Thorns
protect the
tree from
hungry animals.


These long
roots grow deep
underground
where they can
find stored water.

40
EXPLAIN

Shallow roots
can quickly
soak up the
little rain
that falls.

Thick stems
help store
water.

Read a Diagram
What adaptations help desert plants survive?
Clue: Look at the picture and read the captions.
Watch desert plant
adaptations @ www.macmillanmh.com


Desert Adaptations
Make a Model Wet two paper
towels. Then wrap one in wax

paper. This models a plant that
has waxy skin. Use the
uncovered towel
to model a plant
that does not
have waxy skin.
Place your models
in a sunny window.
Compare How do
the paper towels feel later
in the day?

A Succulents, such as this aloe,
are common desert plants. Their
waxy skin and thick leaves are
adapted to store lots of water.

Draw Conclusions How does
waxy skin help desert plants
survive?

Quick Check
Compare and Contrast How are the

roots of a mesquite tree similar to the roots
of a cactus? How are they different?
Critical Thinking A prickly pear cactus

has shallow roots, spines, and waxy
skin. Could it survive in a desert?

Explain your answer.

prickly pear cactus C

41
EXPLAIN


What adaptations help animals?
Desert animals can survive in the desert
because of their adaptations. Here are just
a few of their many adaptations.

Sleeping the Day Away
Can you imagine sleeping all day and
going to school at night? Except for going
to school, this is what many desert animals
do. Rattlesnakes and coyotes, among others,
are nocturnal (nahk•TURN•uhl). Nocturnal
means they sleep during the day. They come
out at night when it is cooler.

A Rattlesnakes are nocturnal.

Keeping Cool
Large ears and thin bodies help animals,
such as the desert jackrabbit, stay cool.
These special features are adaptations that
help animals lose extra body heat.


Blending In
Some desert animals can hide in plain
site. Their body coverings blend in with their
environment. Blending in is an adaptation
called camouflage (KAM•uh•flahzh).
Camouflage helps animals stay safe.

A A jackrabbit’s long ears
help it stay cool.

Quick Check
Compare and Contrast How are desert

animals and plants similar?
Critical Thinking Could an animal with

thick fur survive in a hot desert?
42
EXPLAIN

A Can you see the frog?
Camouflage helps it
blend in with the rock.


Summarize the Main Idea
A desert is a biome
that has a dry
climate and dry,
sandy soil.

(p. 38–39)

Desert plants
have special roots,
stems, and leaves
that help them take in
and store water.
(p. 40–41)

Think, Talk, and Write
Main Idea What adaptations help
desert plants and animals survive?
Vocabulary What is a desert like?
Talk about it.
Compare and Contrast How are
a cactus’s adaptations similar to
a mesquite tree’s? How are they
different?
2WTTS`S\b

/ZWYS

2WTTS`S\b

Desert animals
have adaptations
that help them
stay safe and cool.
(p. 42)


Make a
Study Guide
Make a pyramid fold.
Use it to summarize
what you read
about deserts
and desert
plants and
animals.

Writing Link
Writing a Story
Write a story about life in the desert.
Use information from this lesson to
help set the scene. Remember to
include a beginning, a middle, and
an end.

Critical Thinking Buffalo have
thick, dark coats. They eat mainly
grasses. Could a buffalo survive in
a desert? Explain your answer.
Test Practice Deserts are biomes
with
A cold climate and frozen soil
B wet climate and marshy soil
C dry climate and sandy soil
D hot climate with lots of rainfall

Math Link

Make a Chart
Use the Internet to find the average
temperature for each month in Death
Valley. Record the information in a
chart. Write a sentence to describe
Death Valley’s climate.

-Review Summaries and quizzes online @ www.macmillanmh.com

43
EVALUATE