3 2 animal ways of life (life science)

You can learn many different things about animals when you group them.. This is because animals can be grouped in so many different ways.. Ways of Grouping Animals The way you group anim

Scott Foresman Science 3.2

• Diagram

• Glossary

Animals

ISBN 0-328-13812-6

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Scott Foresman Science 3.2

• Diagram

• Glossary

Animals

ISBN 0-328-13812-6

ì<(sk$m)=bdibci< +^-Ä-U-Ä-U

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?

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

stages of a butterfl y in order Use

the words fi rst, next, then, and

fi nally in your answer.

What did you learn?

Vocabulary

adaptation

hibernate

inherited

larva

migrate

pupa

trait

vertebrate

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.

3 4 5 6 7 8 9 10 V010 13 12 11 10 09 08 07 06 05

by Erika Alexander

Animal Groups

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

3

What All Animals Need

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

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 fi ns are traits that are passed

from parents to their young

5

Animals with a Backbone

A vertebrate is an animal with a backbone

Reptiles, amphibians, fi sh, 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

Animals Without a Backbone

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

7

Animals Grow and Change

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

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 fi rst 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

9

A Butterfl y’s Life Cycle

A butterfl y is an insect

It goes through many changes during its lifetime

First an adult butterfl y 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 butterfl y comes out of the chrysalis Now the butterfl y is

an adult After it lays eggs, the butterfl y completes its life cycle

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

11

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

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

13

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

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

15

Adaptations For Protection

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 camoufl age

to hide from their enemies

Polar bears are adapted to use camoufl age in their snowy environment It is very diffi cult to see a polar bear because the color

of its coat blends in well with snow

Skunk

Behaviors That Help Animals

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 fl y right away

The bird must learn to fl y

Baby birds

17

Instincts

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 fl y 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 fi nd in the winter

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

19

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

Fossilized reptile

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

21

Ancient Insects

Sometimes scientists will fi nd 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

Spider in amber

Fossilized pterodactyl

have been able to look at insects from long ago

How Today’s Animals Compare

With Those of Long Ago

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

Fossilized plants

23

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

Glossary

adaptation a trait that helps a living thing meet

its needs in the place it lives

hibernate to rest during the winter or for a

long period of time

inherited passed on from a parent to

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

between being a larva and an adult

trait a feature passed on to a living thing

from its parents

vertebrate an animal with a backbone

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?

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

stages of a butterfl y in order Use

the words fi rst, next, then, and

fi nally in your answer.

What did you learn?

Vocabulary

adaptation

hibernate

inherited

larva

migrate

pupa

trait

vertebrate

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.

3 4 5 6 7 8 9 10 V010 13 12 11 10 09 08 07 06 05