3 2 animal ways of life (life science)

Genre

Nonfiction

Comprehension Skill

Sequence

Text Features

• Labels
• Diagram
• Glossary

Science Content

Animals

Scott Foresman Science 3.2

ISBN 0-328-13812-6

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Vocabulary
adaptation
hibernate
inherited
larva
migrate

pupa
trait
vertebrate

What did you learn?
1. What are the vertebrates that live in
your area? What do they look like?
2. What are the different stages of an
animal’s life cycle?
3. What adaptation helps a cheetah
get food?
4.

by ErikaAnimals
Alexander
can be
grouped in different ways. Using
your own paper, describe some of
the ways animals can be grouped.
Use details from the book to support
your answer.

Picture Credits
Every effort has been made to secure permission and provide appropriate credit for photographic material.
The publisher deeply regrets any omission and pledges to correct errors called to its attention in subsequent editions.
Photo locators denoted as follows: Top (T), Center (C), Bottom (B), Left (L), Right (R), Background (Bkgd).
2 (L) Terry Andrewartha /Nature Picture Library, (CL) ”Jerry Young/DK Images; 4 (TL) ”Philip Dowell/DK Images;
6 David Wrobel/Visuals Unlimited; 15 (CR) Steve & Dave Maslowski/Photo Researchers, Inc.;
16 (BR) Samuel R. Maglione/Photo Researchers, Inc.; 18 Steve Bloom/Alamy Images; 22 (BL) ”Jerry Young/DK Images;
23 (CR) ”Jerry Young/DK Images.

Scott Foresman/Dorling Kindersley would also like to thank: 10 Jerry Young/DK Images; 12 Jerry Young/DK Images;
19 (T) Natural History Museum/DK Images; 20 (T) Senckenberg Nature Museum, Frankfurt/DK Images.
Unless otherwise acknowledged, all photographs are the copyright © of Dorling Kindersley, a division of Pearson.

ISBN: 0-328-13812-6
Copyright © Pearson Education, Inc. All Rights Reserved. Printed in the United States of America.
This publication is protected by Copyright, and permission should be obtained from the publisher prior to any
prohibited reproduction, storage in a retrieval system, or transmission in any form by any means, electronic,
mechanical, photocopying, recording, or likewise. For information regarding permission(s), write to
Permissions Department, Scott Foresman, 1900 East Lake Avenue, Glenview, Illinois 60025.
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5.

Sequence Describe the life
stages of a butterfly in order. Use
the words first, next, then, and
finally in your answer.


What All Animals Need

Animal
Groups

All animals need food, water, oxygen,
and shelter.
Animals need food and water for their
systems to work. Oxygen is a gas that animals
breathe. They need oxygen to stay alive.

Animals that live on land use their lungs to
breathe. Animals that live in the water use
their gills. Shelter provides animals with a safe
spot to rest or to hide from other animals.

There are lots of different
animals in the world. When
animals are grouped together,
we can see the things they have
in common. You can learn many
different things about animals
when you group them. This is
because animals can be grouped
in so many different ways.

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Ways of Grouping Animals
The way you group animals should
depend on what you want to learn
about them. If you want to learn about
animals’ environments, group them by
where they live. If you want to learn if
animals are herbivores or carnivores,
then group them by what they eat.
Animals can also be grouped
by the traits they share. A trait

is a feature that is passed on to
a living thing from its
parents. Webbed feet
or fins are traits that are passed
from parents to their young.

4

Animals with a Backbone
A vertebrate is an animal with a backbone.
Reptiles, amphibians, fish, birds, and mammals
are all vertebrates.
Reptiles have lungs. Their skin can be dry
and scaly.
Amphibians spend time in the water and
on land. They have gills when they are young.
When they get older, they usually grow lungs.
Fish have gills, never lungs. They live only in
the water.
Mammals have hair during some part of
their lives. All mammals breathe through lungs.
Birds have lungs too. They also have wings,
beaks, feathers, and light bones.

5


Animals Grow
and Change

Animals Without a Backbone

As animals grow and change,
they go through life cycles. Every
animal’s life cycle has a set order.
Animals grow and change in a
certain order.
Certain life cycles take
a long time. Other life cycles
are very short.

Most animals in the world do not have a
backbone. Sea jellies, worms, mollusks, and
arthropods are all animals without a backbone.
Insects and spiders do not have backbones.
Animals without a backbone usually do not
grow very big. Think about how small most
insects and spiders are when compared to a
mammal.
Some animals have a shell or outside skeleton
instead of a backbone. A shell or outside
skeleton can give the animal support.

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7


Life Cycles
All animals come from eggs. Sometimes

the egg grows inside the animal’s mother.
The mother then gives birth to the animal.
Other times, the mother lays the egg. The animal
then hatches from the egg. The first stage of an
animal’s life cycle is birth.
An animal grows bigger during its growth
stage. Then it develops into an adult. Adults give
birth to young animals through reproduction.
An animal’s life comes to
an end with death.

8

A Butterfly’s
Life Cycle
A butterfly is an insect.
It goes through many changes
during its lifetime.
First an adult butterfly lays a
very small egg on a plant. A caterpillar
hatches from that egg. It does not
have wings.
Next the caterpillar eats and grows.
It sheds its skin many times. During
this stage the caterpillar is called a larva.
Then a hard shell, or chrysalis, forms
around the caterpillar. The caterpillar
becomes a pupa. Inside the chrysalis,
the caterpillar keeps changing.
Finally a butterfly comes out of

the chrysalis. Now the butterfly is
an adult. After it lays eggs, the
butterfly completes its life cycle.

9


Mammals go through smaller changes during
their life cycles. They give birth to their young.
Young mammals grow inside their mother’s body.
When mammals are born, they usually have fur
or hair. Young mammals get milk from their
mother’s body. Some mammals grow up quickly.

Other Life Cycles
Snakes are a kind of reptile. Some snakes
live on the land and in the water.
When a female snake is ready, she lays
her eggs in a warm, damp, and dark place.
A young snake uses its egg tooth to cut through
its eggshell. The egg tooth will fall off later.
Snakes can grow very fast. After a baby snake
has grown enough, it sheds its old skin and grows
a new skin.
Most snakes become adults by the time
they are two to four years old. Once a female
snake becomes an adult, she is ready to lay eggs
on her own. The snake life cycle starts again.

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Adaptations
Help Animals
You have learned that animals need food,
water, oxygen, and shelter to stay alive.
Animals also have special features
that help them survive in their
environment. Every environment
is different, so each animal
has adapted to the
environment where
it lives.

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Adaptations
An adaptation is a special trait that helps
animals survive where they live. The camel’s
long thick eyelashes are an adaptation for
the desert. They protect the camel’s eyes
and keep out blowing sand.
A male lion has a
very thick mane around
its neck for protection.
These body part
adaptations are inherited.
Things that are inherited

get passed from adults
to their young.

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Adaptations
For Protection

Adaptations
For Getting Food
All animals need food to
survive. Sometimes they develop
adaptations that make catching
or eating their food easier.
An animal may be adapted to
run very quickly, like a cheetah.
Cheetahs need to chase their
food to catch it.
An animal may have very good
eyesight and hearing. Owls use both
of these senses to hunt at night.
Giraffes have very long necks
so they can eat leaves that grow
in tall trees.

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Many animals have developed
adaptations to protect themselves.

Skunks are small animals that
release a strong-smelling spray
when they are scared.
Other animals use camouflage
to hide from their enemies.
Polar bears are adapted to use
camouflage in their snowy
environment. It is very difficult to
see a polar bear because the color
of its coat blends in well with snow.

Skunk

15


Behaviors That Help Animals

Instincts

Animals behave in many different ways.
A behavior is something that a living thing
does. Animals are born knowing some
behaviors, but animals must learn other
behaviors.
A baby bird is born with wings, but that
does not mean the bird can fly right away.
The bird must learn to fly.

An instinct is a behavior that does not

have to be learned. Animals have instincts.
When the weather changes, some animals
have an instinct to migrate, or move.
Snow geese migrate in large groups during
the winter. They fly from areas that get
very cold to areas that are warmer.
Other animals hibernate or rest for long
periods of time. When animals hibernate,
they go a long time without waking up, eating,
or drinking. Black bears hibernate during
the winter. They hibernate because the food
they eat is harder to find in the winter.

Baby birds

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Learning
Animals are able to learn different ways to
survive in their environment too. Sometimes
an animal will learn a behavior from its parents.
Young wolves learn how to hunt by watching
adult wolves. In the same way, young beavers
learn how to build beaver dams and homes
by watching their parents cut and
move branches and logs.

Fossilized
reptile

Animals Then
And Now
Sometimes looking at the past can help
explain the present. By learning about
animals from the past, you can
also learn about the animals
of today. Today’s animals are
alive because they were able
to adapt. Animals from the
past provide clues about the
changes to animals over time.

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Fossilized
pterodactyl

Ancient Insects

Animals That
Lived Long Ago
We learn about animals from long ago
by looking at fossils. Fossils are signs of past
life. Fossils can be whole skeletons or a single

bone. Sometimes an impression of a skeleton
or bone is found in a rock. By looking at fossils,
fossil molds, and casts, scientists can tell how
big an animal was. Scientists may also be able
to tell whether an animal ate plants or meat, just
by looking at fossils.

20

Sometimes scientists
will find more than just fossil
bones. Whole animals, such as small insects, get
caught in tree sap. Over time, the sap turns into a
hard yellow or brownish substance called amber.
Because we can see through amber, scientists
have been able to
Spider in amber
look at insects from
long ago.

21


How Today’s Animals Compare
With Those of Long Ago

Fossilized plants

22

Scientists like to
study both plant and
animal fossils. From
fossils, scientists can
often figure out what the
weather was like. Using
all of the clues that
fossils give, scientists
are often able to figure
out how today’s animals
adapted to the Earth’s
changes.

Grouping animals helps you
learn more about them. There
are many ways to group animals.
By grouping animals, you can
learn about how animals are the
same and how they are different.

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Vocabulary

Glossary
adaptation
hibernate a trait that helps a living thing meet
adaptation
inherited its needs in the place it lives

larva
migrate to rest during the winter or for a
hibernate
pupa
long period of time
trait
vertebrate passed on from a parent to
inherited
its young

larva

a stage in the life of an insect when
it hatches from an egg and does not
have wings

migrate

to move to another location for
a season or other period of time

What did you learn?
1. What are the vertebrates that live in
your area? What do they look like?
2. What are the different stages of an
animal’s life cycle?
3. What adaptation helps a cheetah
get food?
4.

Animals can be
grouped in different ways. Using
your own paper, describe some of
the ways animals can be grouped.
Use details from the book to support
your answer.

5.

Sequence Describe the life
stages of a butterfly in order. Use
the words first, next, then, and
finally in your answer.

Picture Credits
Every effort has been made to secure permission and provide appropriate credit for photographic material.
The publisher deeply regrets any omission and pledges to correct errors called to its attention in subsequent editions.
Photo locators denoted as follows: Top (T), Center (C), Bottom (B), Left (L), Right (R), Background (Bkgd).
2 (L) Terry Andrewartha /Nature Picture Library, (CL) ”Jerry Young/DK Images; 4 (TL) ”Philip Dowell/DK Images;
6 David Wrobel/Visuals Unlimited; 15 (CR) Steve & Dave Maslowski/Photo Researchers, Inc.;
16 (BR) Samuel R. Maglione/Photo Researchers, Inc.; 18 Steve Bloom/Alamy Images; 22 (BL) ”Jerry Young/DK Images;
23 (CR) ”Jerry Young/DK Images.

pupa

the stage an insect goes through
between being a larva and an adult

Scott Foresman/Dorling Kindersley would also like to thank: 10 Jerry Young/DK Images; 12 Jerry Young/DK Images;
19 (T) Natural History Museum/DK Images; 20 (T) Senckenberg Nature Museum, Frankfurt/DK Images.

a feature passed on to a living thing
from its parents

Unless otherwise acknowledged, all photographs are the copyright © of Dorling Kindersley, a division of Pearson.

trait

ISBN: 0-328-13812-6

vertebrate an animal with a backbone

Copyright © Pearson Education, Inc. All Rights Reserved. Printed in the United States of America.
This publication is protected by Copyright, and permission should be obtained from the publisher prior to any
prohibited reproduction, storage in a retrieval system, or transmission in any form by any means, electronic,
mechanical, photocopying, recording, or likewise. For information regarding permission(s), write to
Permissions Department, Scott Foresman, 1900 East Lake Avenue, Glenview, Illinois 60025.

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