California science grade 5 (7)

▶ Main Idea Vascular plants are classified as seedless and seed plants.. The main parts of vascular plants are roots, stems, and leaves.. Because of this, scientists have classified v

L e s s o n 3

Photosynthesis and Respiration

5 LS 2 Plants and animals have structures for respiration, digestion, waste disposal, and transport of materials.

POETRY

ELA R 5.3.5

Describe the function and effect of common

literary devices (e.g.,

imagery, metaphor,

symbolism)

ELA W 5.2.3 Write

research reports about

important ideas, issues,

or events by using the

following guidelines:

a Frame questions that

direct the investigation

b Establish a controlling

idea or topic.

c Develop the topic

with simple facts,

details, examples, and

explanations.

68

Against the blowing sky the stiff

fabric of branches and twigs grows up and

up into the light

Spreading unseen beneath the tree

a tangle of roots — secret fingers

that feel their way through the unmapped country

underground

Veins thread their thin pattern through every leaf Look how they hold each green hand

open to the sun collecting light and the green diamond-drops of water!

from ECHOES FOR THE EYE

- Journal Write about it online

of this sequence of events

69

Cactus plants need to store and retain water.

Their spines protect the stored water from thirsty animals What do cactus plants have

in common with other vascular plants?

Examine each plant Look at the roots, stems,and leaves

Record Data Make a chart for each plant

Draw what the plant’s root, stem, and leaveslook like Record the color, size, and shape ofeach plant part

Compare Which of the plant parts look similar?

Which parts look different?

Draw Conclusions

How do the stems of the water plant and the cactus compare? Why do they have these differences?

Infer Would the flowering plant be able to survive in a hot, dry area? Why or why not?

Infer Would the water plant be able to surviveout of the water? Why or why not?

Look at the plants where you live Observe threeplants and compare them to these three plants

Based on your observations, decide if each of the plants you observed are also vascular plants

▶ Main Idea

Vascular plants are

classified as seedless and

seed plants Most seed

plants have flowers

What are vascular plants?

Think about the plants you see every day If you go to the park you might see lots of grass, trees, and shrubs Your family might grow roses

or have a vegetable garden in your backyard You might find ferns and other potted plants in your house or classroom What do all of these plants have in common? They are all vascular plants

Vascular plants have specialized cells and tissues that form vessels These vessels work together to transport water, food, and waste to and from all parts of the plant The main parts

of vascular plants are roots, stems, and leaves

The roots of the vascular plant form the root system The root system is usually the portion

of the plant found below the ground The main functions of this system are anchorage and absorption This means the roots hold the plant

in place and take in nutrients and water from the soil Roots can also store food for the plant

no flower flowers

seed

The stem and the leaves of the plant are part of the shoot system

The shoot system is usually the

above-ground portion of the plant The

main functions of the shoot system

are to support the plant, to transport

materials, and to produce food.

If you were to study the life cycles

of vascular plants, you would probably

notice that some vascular plants have

seeds and others don’t Because of

this, scientists have classified vascular

plants into seedless plants and plants

with seeds Seedless plants develop

from spores and seed plants develop

from seeds A spore (spawr) is a

single cell that can develop into a new

plant that is exactly like the plant

that produced it A seed contains an undeveloped plant, stored food, and a protective covering

Plants with seeds are further divided into plants that produce flowers and plants that do not produce flowers.

73

EXPLAIN

How are seedless and

seed plants different?

Most of the plants that you see

every day produce seeds Grasses,

flowering plants, and trees are all seed

plants Seed plants have male and

female structures that produce male

and female cells Seeds are formed

when a male cell and a female cell join.

The undeveloped plant in the seed

uses the stored food to develop and

grow into a new plant This new plant

shares the characteristics of the two

plants that produced the seed.

Seedless vascular plants, such as

horsetails, club mosses, spike mosses,

and ferns, do not produce or grow from

seeds Instead, these plants use spores

to reproduce.

Plants that grow from spores, such

as ferns, first grow a stalk with leaves,

or fronds The underside of the fronds have capsules, or spore cases Each capsule is filled with thousands of tiny spores When the capsule opens, some spores drop to the ground near the parent plant Other spores are blown away by the wind Spores have a tough outer covering It protects them from drying out until they find the right conditions to grow Spores will not grow and produce new plants unless they land near water.

▲ These spore cases, or capsul

arranged at the bottom of a

frond, or leaf They contain m

A seed plant that does not produce flowers is called a gymnosperm

(JIM•nuh•spurm) Gymnosperms

produce seeds inside a cone When the

cone falls, it breaks and releases seeds

The seeds are blown by the wind,

washed away by water, or moved by

animals until they reach a place where

a new plant can grow.

Most gymnosperms are evergreens

Evergreens are trees that lose only a

few leaves at one time and constantly

replace the leaves they have lost So,

they look green all the time.

Quick Check

Sequence How do seed and seedless plants develop? List the steps for each.

Critical Thinking How are spores and gymnosperm seeds similar?

How are spores and seeds different?

Clue: Look at the size and covering of spores and the seeds

Reading Photos

▼ Apples are fruits

that contain seeds

The seeds can be planted to grow new apple trees

◀ apple tree branch

Fern Spores

Observe Carefully examine a fern leaf Draw what you see and write down any observations

Place a drop of water on a slide

Use a toothpick to scrape one of the spore cases into the drop of water

Observe Examine the spore case under the microscope on low power What does the spore case contain?

Draw what you see and write down any observations

Infer How does the size

of the fern spores relate

to their function?

75

EXPLAIN

What do flowers do?

Flowers are the reproductive organ

of angiosperms Flowers usually have

both male and female structures The

male part of the flower, the stamen

(STAY•muhn), produces male cells,

or pollen grains Pollen grains are

transferred from the top of a stamen

to the female part of the flower, the

pistil (PIS•tuhl), or to another flower’s

pistil This transfer is called pollination

(pol•uh•NAY•shuhn).

Flowers have bright colors, scents, and nectar to attract animals such as

insects, birds, and small mammals

These animals become pollinators

when they accidentally transfer pollen

from one flower to another

Once the flower is pollinated, the pollen travels down the pistil until it

reaches the female cell, the egg cell

When the pollen and egg cell join, they

form a seed This is called fertilization

(fur•tuh•luh•ZAY•shuhn) As the seed develops, the ovary enlarges until it becomes a fruit The fruit protects the seeds inside it

Seeds are dispersed (di•SPURSD),

or scattered, in many ways Some seeds have structures, like wings, that enable them to be carried by the wind

Other seeds are moved by animals

Some have hooks that get stuck to an animal’s fur or feathers Animals that eat fruit cannot digest the seeds They help with dispersal by depositing the seeds in their waste If a seed reaches a place where conditions are right for a new plant to grow, it will sprout.

Clue: Examine the stamen and the pistil in the diagram

Reading Diagrams

stamen pollen grains

(pp 72–73)Some plants grow from

spores Others grow from seeds (pp 74–75)

Flowers are

reproductive organs that produce seeds

(p 76)

Think, Talk, and Write Main Idea How are vascular plants classified?

Vocabulary Plants that have seeds but

do not have flowers are called _

Sequence How are plant seedsdispersed?

Summarize the Main Idea

C seedless vascular plants

D vascular plants with flowers

Test Practice All of the following are part of a flower EXCEPT

Suppose you were a tiny pollen grain

or a seed Tell about the things that

happen as you are dispersed

Calculate Seeds

Apples have about 12 seeds Suppose only 1/4 of the seeds will grow into newtrees If a tree grows 150 apples, howmany seeds will become new trees?

- Review Summaries and quizzes online @www.macmillanmh.com 77

EVALUATE

smooth leaf palmate leaf

Classify

When scientists classify , they place things that share

traits or characteristics into groups In order to do that,

scientists need to compare and contrast Remember, to

compare you look for how things are alike To contrast

you look for how they are different.

Learn It

Classifying is a useful tool for organizing and analyzing

things When you classify, you can learn the characteristics

of millions of things, without actually having to learn about

each one For example, you may not know all the different

kinds of bicycles there are in the world, but you know

something about all bicycles: Bicycles have two wheels

It is a good idea to keep notes of the criteria, or rules,

you use to classify things An example of a criterion is the

number of wheels something has If you decide to classify

things by the number of wheels they have, cars, pickup

trucks, and carts would be in the same group because they

all have four wheels Motorcycles and bicycles would be in

the same group because they have two wheels

One way to classify things is by their shape You can

classify leaves by the shape of their edges Here are some

examples of the different types of leaf edges

5 IE 6.a Classify objects (e.g., rocks, plants, leaves) in accordance with appropriate criteria.

78

EXTEND

Try It

▶ Find ten leaves of different kinds,

shapes, and sizes

▶ Examine each of your ten leaves one at

a time

▶ Draw your leaves on a chart similar to

the one shown

▶ Write a description of each leaf next to

the picture

▶ Classify your leaves according to the

type of edge each has Use the leaves

on the previous page as a guideline

Record the type of edge on your chart

Apply It

▶ Look around you for more things to

classify Choose something you are interested in or enjoy Think of things you see every day, such as plants, rocks, or animals

▶ Classify them by size, shape, color, or any other characteristic that they have

in common Share your findings with the class

79

EXTEND

Mangrove trees are very important to shoreline

environments Their large, entangled roots provide

protection for smaller organisms How do their large

roots help the mangroves get water?

80

ENGAGE

What will happen if you leave a celery stalk

in colored water? Make a prediction

Test you Prediction Observe Use a hand lens to look at the celery stalk

Place the celery stalk in a container with water

Put three drops of food coloring into the container Stir the water until the food coloring is thoroughly mixed

Record Data Use colored pencils to draw

a picture of the celery stalk Record the date and time

Observe On the following day, use the hand lens

to look at the celery stalk Note any changes

Record Data Use colored pencils to draw

a picture of the celery stalk Record the date and time

You used a celery stalk in this experiment What doyou think would have happened if you used a plantthat had a white flower? Answer this question bymaking a prediction and a plan to test it Then follow your plan and write a report of your results

▶ Main Idea 5 LS 2.a

Vascular plants have

special structures for the

Quick Check

Cause and Effect How do plants move minerals from the soil to the tips of their leaves?

Critical Thinking What would happen to the amount of sugar produced if there was a drought?

Transport in Vascular Plants

How does the sugar produced

in the leaves get to the roots?

Clue: Look at the labels

Read the descriptions to find the answer

Reading Diagrams

Leaf Sugar is produced

in the leaves

Trunk or Stem The

trunk or stem has

tissues that move

water and minerals

from the roots to the

leaves and move the

83

EXPLAIN

What is the transport

system made of?

When you cut a thin slice of a plant

stem or root and look at it under a

microscope, you can see the tissues that

form the transport system.

One of these tissues is xylem

(ZIGH•luhm) Xylem moves water and

minerals up from the roots As water

moves up the plant, some of it is stored

in the vacuoles of the xylem tissue

cells Most of the layers of a tree trunk

are made of xylem.

Phloem(FLO•em) is the other tissue

in the transport system It moves the

sugar produced in the plant’s leaves to

its other parts

Many stems have a layer of cells that separate the xylem from the phloem This layer is called the cambium(KAM•be•uhm) The cambium

is where new xylem and phloem cells are produced.

▲ This is a magnified cross section

o a butte cup oot

Woody and Soft Stems

84

EXPLAIN

The outer layer of a woody stem, such as a tree trunk, is called bark.

Bark is a tough outer covering that

serves as a protective layer for the tree

It can be thin or very thick with deep

ridges Inside the bark, there is a layer

of phloem Inside the layer of phloem is

more xylem.

Each year, a new layer of xylem forms an annual ring You can estimate

the age of a tree by counting the

number of annual rings Trees grow

out in a circle, so the center of a tree

is the oldest part

You can also use the annual tree rings to tell what the weather was as

the tree was growing Each annual ring

is made up of a lighter and a darker

part The lighter rings form during the

spring when there is plenty of water and

growing conditions are good for the tree.

The darker rings grow during autumn

when there is less water available Years

with lots of rain produce larger rings

of growth and years with less rain

produce much smaller rings.

California It is 4,767 years old

Root Cross Section

Observe Examine a cross section

of a root with a hand lens Drawwhat you see

Place the cross section and a fewdrops of water on a slide Cover itwith a cover slip Look at it under

a microscope at low power

Draw what you see Label the parts that you can identify

Draw Conclusions Which parts

of the root carry wcan you tell?

Communicate Othgroups in your clalooked at differen

of roots Discuss wtheir cross sectionsimilar or differenfrom yours

85

EXPLAIN

◀ Corn plants have prop roots

How are roots different?

There are several different kinds of

roots Taproots have one large root

with a few branching, hairy roots

Dandelion, carrot, and beet plants

have taproots Taproots tend to grow

deep into the soil and can often reach

underground sources of water.

Fibrous roots are made up of thin,

branching roots Grasses have this type

of root Fibrous roots can have huge

networks of roots underground

Prop roots grow like fingers out of

the bottom of the stem These roots

help support, or prop up, the plant

Corn plants and mangrove trees have

prop roots.

Some plants have aerial roots, or

roots that never touch the ground.

Plants with these roots include some types of ivy and orchids Some orchids live high in the branches of rain forest trees Since their roots cannot reach the ground, the roots of these plants take

in water from moisture in the air.

▲ Grass has fibrous roots

86

EXPLAIN