all animals have life cycles

Genre Comprehension Skill Text Features Science Content
Nonfi ction State the Purpose • Captions
• Labels
• Diagrams
• Glossary
Animal Life Cycles
Scott Foresman Science 2.4
Standards
Preview
Standard Set 2. Life Sciences
2. Plants and animals have
predictable life cycles. As a basis for
understanding this concept:
2.b. Students know the sequential
stages of life cycles are different for
different animals, such as butterflies,
frogs, and mice.
ISBN 0-328-23504-0
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Life Sciences
by Kristin Cashore
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Vocabulary
amphibian
insect
larva
life cycle
mammal
pupa

tadpole
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.
Unless otherwise acknowledged, all photographs are the copyright of Dorling Kindersley, a division of Pearson.
ISBN: 0-328-23504-0
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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All Animals Have
Life Cycles
by Kristin Cashore
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The Life Cycles of
Living Things
Living things grow and change. A kitten does
not stay a kitten. It grows into an adult cat.
A life cycle is the way a living thing grows
and changes. All animals have life cycles.
Cats have life cycles.
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Every life cycle has stages. At each stage,
the animal looks different. All animals change
size as they grow. Many animals also change

shape. Some animals even change color!

A caterpillar and a
butterfl y are part of
the same life cycle.
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Different Life Cycles
Different animals have different life cycles.
A mammal is one kind of animal. Mammals
have hair or fur on their bodies. Skunks are
mammals. Dogs and cats are mammals too.
Giraffes are mammals.
Their bodies have hair.
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Young mammals look a lot like their parents.
Mammals grow bigger as they get older. Some
mammals also change color as they get older.
Elephants are mammals.
They grow bigger as they
get older.
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Young Insects and Amphibians
An insect is an animal with three body parts
and six legs. A ladybug is a kind of insect. Ants
and butterfl ies are insects too.
Young insects look very different from their
parents. Insects change size, shape, and color

as they get older.
Ladybug eggs
An adult ladybug
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An amphibian is an animal that lives part
of its life in the water. It lives the other part of
its life on land. Newts are amphibians. Frogs
and toads are also amphibians.
Young amphibians look different from their
parents. Amphibians change size, shape, and
color as they get older.
How is the young newt
(left) different from the
adult newt (below)?
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What is the life
cycle of a toad?
A toad is an amphibian. It starts life as an
egg. The egg hatches and a tadpole swims out.
A tadpole is a very young toad or frog.
A tadpole lives only in water. It has a tail,
but it does not have legs. Soon the tadpole
starts to change. It grows back legs. Then it
grows front legs. Its tail starts to get smaller.
A toad egg
A young tadpole
An adult tadpole
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Finally, the tadpole starts to look like a toad!
An adult toad has four legs. It does not have a
tail. It can live on land or in the water.
The adult toad may lay eggs in the water.
Then the life cycle starts over.
An adult toad
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What is the life
cycle of a horse?
A horse is a mammal. Baby horses are called
foals. Foals look like their parents. Foals can
stand up an hour after they are born!
A foal
A young horse
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A female foal grows into a fi lly. A male foal
grows into a colt. Colts and fi llies look more like
adult horses than foals. After two or three years
colts and fi llies become adult horses. Then they
can have foals of their own.
An adult horse
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What is the life
cycle of a butterfl y?
Many insects have life cycles that are four
stages. A butterfl y is an insect. Its life cycle has

four stages. A butterfl y starts life as an egg.
Then a larva hatches from the egg. This is
the next stage. A larva is a young insect. A
butterfl y larva is called a caterpillar.
butterfl y egg
caterpillar
pupa
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The caterpillar turns into a pupa. Its wings
start to grow.
The pupa turns into an adult butterfl y in the
fi nal stage of the life cycle. The butterfl y looks
very different from the caterpillar!
The adult butterfl y may lay eggs. Then the
life cycle of the butterfl y starts over.
young butterfl y
adult butterfl y
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What is the life
cycle of a dragonfl y?
A dragonfl y is an insect. Its life cycle has
three stages. A dragonfl y starts life as an egg.
The dragonfl y egg hatches. A young
dragonfl y crawls out. It is called a nymph. The
nymph looks a lot like an adult dragonfl y. It has
three body parts and six legs. The nymph does
not have wings.
dragonfl y egg

nymph
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The nymph grows bigger. It grows two sets
of wings. Finally, it becomes an adult dragonfl y!
The adult dragonfl y may lay eggs. Then the
life cycle of the dragonfl y starts over.
adult dragonfl y
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amphibian an animal that lives part of its
life in water and part on land
insect an animal that has three body
parts and six legs
larva a young insect
life cycle the way a living thing grows and
changes
mammal an animal that has hair or fur on
its body
pupa the stage after the larva in some
insects’ life cycles
tadpole the second stage of a frog’s life
cycle
Glossary
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What did you learn?
1. What are some ways a mammal may change
during its life cycle?
2. What are the three stages of a horse’s life
cycle?

3.

All animals grow and
change. Describe how a class pet or one you
have at home has grown and changed since
you fi rst saw it.
4.

State the Purpose Go back to the
caption on page 7. What is its purpose?
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