by Kim Fields

Scott Foresman Science 3.1

Genre Comprehension Skill Text Features Science Content

Nonfi ction Compare and Contrast

Captions

Glossary

Plants

ISBN 0-328-13808-8

Vocabularyconiferous

deciduous

extinct

fossil

germinate

pollinate

seed leaf

seedling

system

What did you learn?1. How do roots help a plant stay alive?

2. What are some different ways that seeds are scattered to make new plants?

3. How have plants changed over time?

4. In this book, you have read about pollination. Write to explain how petals help pollination. Use details from the book as you write.

5. Compare and Contrast How are deciduous and coniferous trees alike? How are they different?

Illustration: 7 Alan Barnard; 17 Alan Barnard; 23 Alan BarnardPhotographs: 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 property of Scott Foresman, a division of Pearson Education. Photo locators denoted as follows: Top (T), Center (C), Bottom (B), Left (L), Right (R), Background (Bkgd).Title Page: Lou Jacobs Jr./Grant Heilman Photography; 2 John Warden/Index Stock Imagery; 4 DK Images; 5 (R) Silver Burdett Ginn, (CL) DK Images; 8 Lou Jacobs Jr./Grant Heilman Photography; 9 DK Images; 10 DK Images; 11 (T) Jeff Lepore/Photo Researchers, Inc., (B) Stone/Getty Images; 12 Carolina Biological/Visuals Unlimited; 13 (CR) DK Images, (TL) Brad Mogen/Visuals Unlimited; 14 (TL) John Poutier/Maxx Images, Inc., (TR) Darryl Torckler/Getty Images; 15 (TL) Brian Gordon Green/NGS Image Collection, (TR) Jorg & Petra Wegner/Animals Animals/Earth Scenes; 16 Nigel Cattlin/Photo Researchers, Inc.; 18 (BR) Kenneth W. Fink/Photo Researchers, Inc., (CC) DK Images, (TR) Nigel Cattlin/Photo Researchers, Inc.; 19 Nigel Cattlin/Holt Studios; 20 (CL) Neg./Transparency No. K13073. Courtesy Dept. of Library Services/American Museum of Natural History, (BC) John Cancalosi/Peter Arnold, Inc., (CR) Dr. E. R. Degginger/Color-Pic, Inc.; 21 David Muench/ Muench Photography, Inc; 22 (T) The Natural History Museum, London, (C) Wolfgang Kaehler/Corbis.

ISBN: 0-328-13808-8Copyright 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 permissions, 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

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Plants and How They Growby Kim Fields

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What are the main parts of a plant?What All Living Things Need

Living things have needs. Plants and animals

need food, air, water, and space to live and grow.

Animals need to find food to eat. Plants are

different. They can make their own food. Plants

use energy from the Sun to make food.

2

This Alaskan brown bear is looking for food.

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3

These black-eyed Susans make their own food.

Plants come in all sizes and shapes. They can grow

almost anywhere. Each plant needs special things

to grow. Most plants have four parts. Roots, a stem,

flowers, and leaves are the four main parts.

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4

Why Plants Need Leaves

Plants need leaves to make food. The leaves make

a type of sugar. A plants leaves are a part of its leaf

system. A system has parts that work together.

Carbon dioxide gas enters a plant through holes

in the leaves. Water enters a plant through the roots

and stem. Leaves also take in sunlight. Water and

carbon dioxide are changed into sugar and oxygen.

Energy from sunlight does this. The sugar is the

plants food. The oxygen goes out through holes in

the leaves.

This is what a plant needs to make food.

Carbon DioxideCarbon dioxide goes in.

OxygenOxygen comes out.

SunlightSunlight goes in.

WaterWater goes in.

SugarSugar goes to roots.

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5

Other Ways Leaves Help Plants

Leaves also help a plant take in water. Leaves can

let out extra water through tiny holes. A plant that

lives in dry places may have fuzzy leaves. This helps

keep water inside the plant.

Some leaves help keep the plant

alive. Leaves can be tough or sharp.

They can be filled with poison.

These leaves keep animals from

eating them.

The oak leaf is different from the leaves on a fir tree.

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Why do plants need roots and stems?How Roots Help Plants

Roots hold plants in the

ground. They store food for

the plant. Roots draw water

and minerals out of the soil.

Many plants have a taproot.

Taproots are large roots that grow

deep in the soil. They store food

for the plant. Have you eaten

a beet or a carrot? If so,

youve tasted a taproot!

Beets and carrots are roots you can eat.

Beet

Carrots

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7

There are small root hairs at the tips of roots. Roots

with their many hairs grow deep into the soil. These

hairs take in water for the plant.

Tubes carry water to the stem and leaves. The Sun

can dry out a plant. On hot days, roots take in water

to replace what is lost.Water moves from the root hairs into the root. Then it travels up to the stem and leaves.

Root hair

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How Stems Help Plants

A stem holds up a plants leaves, fruits, and flowers.

Its tubes move water from the roots to the leaves.

Others tubes take food from the leaves to the stem

and roots.

Some stems are thin and grow along the ground.

These stems can grow roots and a new plant.

Cactus stems are fat and have a thick covering.

This helps keep water inside the plant.

8

These cactus plants have thorns. The thorns are special leaves.

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9

Potatoes are stem parts that grow underground.

They store food for the plant. New stems can grow

from a potatos buds. The buds are also called eyes.

Some stems have special parts that keep plants safe.

Some stems have hairs that sting animals. Other stems

have thorns. Both thorns and stinging hairs help keep

animals away.

Potatoes can be eaten. But you must dig them out of the ground.

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10

How are plants grouped?Flowering Plants

Grasses and trees are types of plants. Trees have

a strong, woody stem to hold them up. Grasses do

not have woody stems. They grow near the ground.

In the fall, many grasses keep only their roots alive.

In the spring they grow a new stem with leaves.

In the fall many trees leaves die and fall off. These

trees are deciduous. Deciduous trees grow new leaves

in the spring.

These plants and trees both have flowers. The trees are tall. The plants are short.

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11

Making Seeds

Flowers have special parts that make pollen. The

petals of a flower attract insects or other animals. They

often move the pollen. Wind can also pollinate a

flower. This happens when pollen is moved to the part

of another flower that makes seeds. When a flower is

pollinated, seeds form. Fruit grows around the seeds

to protect them.

This bee moves pollen from another plant to the seed-making part of the flower.

Pollen

Seed-making part

Petal

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Coniferous Trees

Coniferous trees do not lose their leaves

all at once. They do not grow flowers. They

have cones that make seeds. The leaves of

these trees look like needles. Pine, spruce,

hemlock, and fir are coniferous trees.

12

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Two Types of Cones

Coniferous trees make two kinds of cones. One cone

is a small pollen cone. The other is a large seed cone.

A seed starts to grow when pollen from the pollen

cone of another tree attaches to the seed cone. Seeds

fall to the ground when they are ripe. Sometimes the

seeds grow into trees.

13

Pollen from these small cones needs to reach seeds in a bigger cone. Wind makes this happen.

Seed

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14

How do new plants grow?Scattering Seeds

Seeds are scattered so they can grow in new places.

Some seeds are scattered by water. Wind can carry

seeds that are very light. Animals carry other seeds

away. Sometimes animals eat the seeds fruit. The seed

passes through the animals body. Then it is dropped

to the ground. Other seeds are scattered when they

stick to an animals fur.

A seed can stick to fur.

A seed can blow away in the wind.

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15

Special Ways of Releasing Seeds

Some types of cones need to be heated by a forest

fire. Then the cones can release their seeds. The fire

also removes other plants around the trees. This

makes space for the seeds to grow.

A seed can float away in water.

A seed can be eaten.

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Germinating and Growing

Seeds come in different colors, sizes, and shapes.

Every seed has a tiny plant inside it. Every seed also

has a seed coat. This protects the plant inside the seed.

The tiny plant can grow into a new plant.

Every seed has one or more seed leaves. A seed leaf

gives food to the new plant.

Seed coat

Tiny plant

Seed leaf

16

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17

Seeds need special things to sprout, or germinate.

They need air, the right temperature, and enough

water. When things are right, a seed sprouts. The

seed breaks open and a seedling, or young plant,

begins to grow. A young root grows down. A stem

with leaves grows up. This plant uses food stored in

its seed to grow.

This seed has germinated.

This seedling has sprouted. It needs water and sunlight to grow.

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18

Life Cycle of a Plant

First, a seed must germinate. Next, a

seedling grows a root downward into the

soil. Then, the seedlings stem grows upward.

Then the stem grows leaves. Finally, the

leaves use sunlight to make sugar for the

plant to eat.

This peanut plant starts out as a seed. What happens next?

Seed

Germinating seed

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19

Soon the seedling grows into an adult plant with

flowers. The flowers are pollinated and new seeds

grow. If the seeds germinate they grow into new

plants. Then the cycle starts again.

Seedling

Adult plant

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20

How are plants from the past like todays plants?Plants That Lived Long Ago

A fossil is the remains of a living thing. Fossils

come from plants or animals that lived long ago.

We can learn about plants by studying fossils.

A fossil forms after a plant dies. The plant gets

pressed into mud and rots away. The mud keeps the

plants form. Over time, the mud hardens into rock.

When the rock cracks open, you can see the fossil.

Ferns

Horsetail

These are fossils of extinct plants.

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Petrified fossils form when rock replaces plant parts.

Sometimes a tree gets buried in the ground. Minerals

from water replace the trees wood. Over a long time,

the wood becomes stone.

When a plant becomes extinct, none of its kind

will ever live again. Ferns that live today are different

from extinct ferns.

21

Petrified wood fossils

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22

Plants Change Over Time

By studying fossils, weve learned that the first

plants did not have flowers or cones. But plants

changed over time. Trees that made cones spread over

Earth. Plants with flowers started to grow.

This is a fossil of a magnolia leaf.

Some magnolias bloom all at once in spring. Then new leaves grow.

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23

Magnolias are flowering plants. They have grown

and changed over millions of years. Magnolias from

long ago kept their leaves year-round. Now, some

magnolias lose their leaves in the fall. But magnolia

flowers have stayed the same for millions of years.

Plants grow all over the Earth. They grow and live

in different ways. Plants make food energy from light

energy. Without them, life would be impossible!

Magnolia trees grew on Earth when dinosaurs lived here. Dinosaurs are extinct. Magnolia trees are still found on Earth.

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24

Glossary

coniferous does not lose its leaves in the fall

deciduous loses its leaves in the fall

extinct type of living thing no longer alive

fossil remains of a living thing from long ago

germinate to begin to grow

pollinate when pollen is moved to a flower part

that makes seeds

seed leaf part of a seed that provides food for the

new plant

seedling young plant

system a set of parts that work together

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Vocabularyconiferous

deciduous

extinct

fossil

germinate

pollinate

seed leaf

seedling

system

What did you learn?1. How do roots help a plant stay alive?

2. What are some different ways that seeds are scattered to make new plants?

3. How have plants changed over time?

4. In this book, you have read about pollination. Write to explain how petals help pollination. Use details from the book as you write.

5. Compare and Contrast How are deciduous and coniferous trees alike? How are they different?

Illustration: 7 Alan Barnard; 17 Alan Barnard; 23 Alan BarnardPhotographs: 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 property of Scott Foresman, a division of Pearson Education. Photo locators denoted as follows: Top (T), Center (C), Bottom (B), Left (L), Right (R), Background (Bkgd).Title Page: Lou Jacobs Jr./Grant Heilman Photography; 2 John Warden/Index Stock Imagery; 4 DK Images; 5 (R) Silver Burdett Ginn, (CL) DK Images; 8 Lou Jacobs Jr./Grant Heilman Photography; 9 DK Images; 10 DK Images; 11 (T) Jeff Lepore/Photo Researchers, Inc., (B) Stone/Getty Images; 12 Carolina Biological/Visuals Unlimited; 13 (CR) DK Images, (TL) Brad Mogen/Visuals Unlimited; 14 (TL) John Poutier/Maxx Images, Inc., (TR) Darryl Torckler/Getty Images; 15 (TL) Brian Gordon Green/NGS Image Collection, (TR) Jorg & Petra Wegner/Animals Animals/Earth Scenes; 16 Nigel Cattlin/Photo Researchers, Inc.; 18 (BR) Kenneth W. Fink/Photo Researchers, Inc., (CC) DK Images, (TR) Nigel Cattlin/Photo Researchers, Inc.; 19 Nigel Cattlin/Holt Studios; 20 (CL) Neg./Transparency No. K13073. Courtesy Dept. of Library Services/American Museum of Natural History, (BC) John Cancalosi/Peter Arnold, Inc., (CR) Dr. E. R. Degginger/Color-Pic, Inc.; 21 David Muench/ Muench Photography, Inc; 22 (T) The Natural History Museum, London, (C) Wolfgang Kaehler/Corbis.

ISBN: 0-328-13808-8Copyright 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 permissions, 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

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