Focus on California Life Science 7th Grade Unit 3 - Chapter 10 Structure and Function of Plants

Chapter Structure and 10 Function of Plants Standards Preview All living organisms are composed of cells , from just one to many trillions , whose details usually are visible only through a microscope . As a basis for standing this concept Students know that liberate energy for the work that cells do and that capture sunlight energy for photosynthesis A typical cell of any ism contains genetic instructions that specify its traits . Those traits may be modified by tal influences . As a basis for understanding this concept . Students know the differences between the life cycles and reproduction methods of sexual and asexual organisms . The anatomy and physiology of plants and animals illustrate the complementary nature of ture and function . As a basis for understanding this concept . Students know plants and mals have levels oi tion for structure and function , including cells , tissues , organs , organ systems , and the whole organism . Students know the structures and processes by which ing plants generate pollen , seeds , and fruit . The plant produces delicate , highly scented . 356

Preview . fa SCION Seed Plants Focus on the BIG Idea How does the structure of a plant allow it to grow and reproduce ?

Check What You Know Suppose you were to put a healthy , growing plant into a completely dark room for two weeks . How would this affect the growth of the plant ?

Explain your answer . Chapter 10 357 The images shown here represent some of the key terms in this chapter . You can use this vocabulary skill to help you understand the meaning of some key terms in this chapter . Academic Words academic words are words that are used frequently in classrooms . academic words appear frequently in books . Look for the words in the table as you read this chapter . consist ( kun SIST ) 363 , 382 diverse ( duh ) 371 survival ( sur ) 379 transport ( trans ) 365 , 381 I Definition To be formed or made of ad . Different , varied The act of staying alive or existing To carry from one place to another Example Sentence Plant stems consist of several kinds of cells . California has a diverse population , including people from many different countries . The survival of the accident victim depends on quick medical attention . Trucks transport products from factories to stores .

, Chapter 10 . I Vocabulary I . Section ( page 362 ) i cuticle I ' vascular tissue zygote la nonvascular plant vascular plant I gametophyte Section ( page 370 rhizoid Section ( page 375 ) phloem xylem pollen seed embryo cotyledon . germination I Section ( page 380 ) if iv ' root cap A Cambium iv ' transpiration Section ( page 338 ) gymnosperm petal cone stamen ovule pistil . pollination ovary angiosperm fruit flower monocot sepal dicot Build Science Vocabulary Online Visit Web Code Chapter 10 359

Sequence Science textbooks often describe is , the order in which events happen . A cycle is a sequence that does not have a beginning or end . When the final event is over , the first event begins again . You will learn about complex life cycles of plants in this chapter . Here is a simplified description of one life cycle . Many plants reproduce by means of seeds . At some point after a seed falls on the ground , the seed sprouts . Slowly , the new plant grows . After a time . flowers appear . Seeds form in flowers . When the seeds are fully developed , they fall onto the ground . Sooner or later , some of these new seeds will sprout . The partially completed cycle diagram below shows the sequence of events described in the paragraph . Seed falls on ground . Seed sprouts . I Flowers Plant appear . grows . Apply It ! In your notebook , complete the diagram shown above . After you read Section , draw a cycle diagram of a plant life cycle , including the sporophyte and the gametophyte stages . After reading Section , prepare two cycle for and one for angiosperms .

Cycle of a Lifetime ' How long is a seed plant life ?

Redwood trees can live for thousands of years . Tomato plants die after only one season . Can organisms that seem so different have anything in common ?

In this chapter , you find out . Some answers will come from this chapter investigation . In this project , you grow plants from seeds and then care for the plants until they produce seeds . Your Goal To care for and observe a plant throughout its life cycle To complete this investigation , you must grow a plant from a seed observe and describe key parts of your plant life cycle , such as seed germination and pollination harvest and plant the seeds that your growing plant produces follow the safety guidelines in Appendix A Plan It ! Observe the seeds that your teacher gives you . In a small group , discuss what conditions the seeds might need to grow . What should you look for after you plant the seeds ?

What changes do you expect your plant to undergo during its life cycle ?

When you are ready , plant your seeds .

The Plant Kingdom Standards Focus , students know , and What Do Leaves Reveal About Plants ?

animals have levels of organization . Your teacher will give you two leaves from plants that grow in ?

arid ' two very different environments a desert and an area with ing cells . tissues , organs , organ average em and the ' Carefully observe the color , size , shape , and texture of the What do plants leaves . Touch the surfaces of each leaf . Examine each leaf with a sham ?

hand lens . Record your observations in your notebook . what do plants need to live . When you have finished , wash your hands on rand thoroughly with soap and water . How do nonvascular plants and Think it Over Plant ! differ ?

Inferring Use of the , What are the different stages of structure of the leaves to determine Plan We Cycle ?

which plant lives in the desert . Explain . Key Terms cuticle vascular tissue zygote There are some very strange plants in the world . There are vegetative reproduction plants that trap animals , plants that bloom only once every Plant thirty years , and plants with that smell like rotting ' meat . You don see these plants every day . But whenever you . te see moss on a tree trunk , a grassy lawn , or ripe tomatoes in a garden , you see plants . And all plants , both the unfamiliar and the familiar . have a lot in common . What Is a Plant ?

Members of the plant kingdom share several characteristics . Nearly all plants are autotrophs , organisms that produce their food . All plants are that contain many cells . In addition , all plant cells are surrounded by cell walls . Autotrophs Plants are autotrophs . You can think of a plant as a , factory . Sunlight provides the energy for this process , photosynthesis . Plant Cells Plants are multicellular . Recall that plant cells are enclosed by a cell wall . Many plant cells also tain and a large vacuole for storing water , wastes , food , and other substances . 352

Plant Body Organization Like many other multicellular Organ A leaf an organ made up of many layers of tissue that worl together to carry out photosynthesis Tissues The leaf contains several kinds of tissue . Some tissues protect the leaf . Others are specialized for photosynthesis . Still others carry food and water . contains stems and leaves . These cells contain that capture ! the sun energy In system photosynthesis . Cell structure Each cell has a cell wall , nucleus , and other . organisms , plants have levels of organization for structure and function . Figure shows some of the cells , tissues , organs , and FIGURE organ systems that make up a typical plant . Plant Body Structure Take a look at the leaf . Notice that it is made of layers of similar The body of a plant is organized cells . Recall that tissues are groups of similar cells that perform a ' function . The layer of cells that cover the outer ' Mat faces of the leaf is one type of tissue . The layers of tightly packed yum , the can , of the leaf cells with make up another type of tissue . Tissues specialized to do ?

work together to form organs . Leaves , stems , and roots are organs . Organs that work together to perform a major function prise organ systems . A plant has two organ above ground and one below ground . Above ground is the shoot system , which consists of stems , leaves , and buds . The shoot system duces food for the plant . Below ground is the root system . Asyou can probably guess , the root system consists of roots , which absorb water and nutrients and anchor the plant in the soil . 363

Adaptations for Living on Land Most plants live on land . How is living on land different from living in water ?

Imagine multicellular algae in the ocean . The algae obtain water and other materials directly from the water around them . Their bodies are held up toward the sunlight by the water . The water also aids in reproduction , a ' water allowing sperm cells to swim to egg cells . ants have help Now imagine plants living on land . What adaptations would help them meet their needs without water all around them ?

GTO survive on land , plants must have structures that allow them to obtain water and other nutrients from their surroundings , retain water , transport materials in their bodies , support their bodies , and reproduce . them retain water . The shiny , waterproof cuticle on this leaf slows down evaporation . obtaining Water and other Nutrients Recall that all organisms need water to survive . Obtaining water is easy for algae because water surrounds them . To live on land , though , plants need adaptations for obtaining water from the soil . Plants must also have ways of obtaining nutrients from the soil . Retaining Water Plants must have ways of holding onto the water they obtain . Otherwise , they could easily dry out due to evaporation . When there is more water in plant cells than in the air , the water leaves the plant and enters the air . One adaptation that helps a plant reduce water loss is a waxy , waterproof layer called the cuticle . A cuticle covers the leaves of most plants . Reviewing Math Statistics , Data Analysis , and Probability Data Water Loss in Plants The graph shows how much water a certain plant loses during the hours shown . Reading Graphs What variable is plotted along each axis ?

VI interpreting Data During what part 150 of the day did the plant lose the most water ?

The least water ?

Drawing Conclusions What could cause this pattern of water loss ?

Predicting How would you expect the graph to look from 10 . to ?

Explain your reasoning . Noon . 89 . 10 Time of Day 3640 FIGURE transport and Support For this tall coconut palm to survive , it must ' water , minerals , and food over long distances . must also support its body so its leaves are exposed to sunlight . Transporting Materials A plant needs to transport water . minerals , food , and other materials from one part of its body to another . In general , water and minerals are taken up by the bottom part of the plant , while food is made in the top part . But all of the plant cells need water , minerals . and food . In small plants , materials can simply move from one cell to the next . But larger plants need a more efficient way to transport materials farther , from one part of the plant to another . These plants have transporting tissue called vascular tissue . Vascular tissue consists of tubelike structures inside a plant through which water , minerals , and food move . Support A plant on land must support its own body . It easier for small , plants to support themselves . But for larger plants to survive , the leaves must be exposed to as much sunlight as possible . Rigid cell walls and vascular tissue strengthen and support the large bodies of these plants . Reproduction All plants undergo sexual reproduction that involves fertilization , the joining of a sperm cell with an egg cell . The fertilized egg is called a zygote . For algae and some plants , fertilization can only occur if there is water in the environment . This is because the sperm cells of these we plants swim through the water to the egg cells , Other plants . however , have adaptations that makes it possible for tion to occur in dry environments . Many plants can also reproduce . tion in plants by asexual methods is called vegetative reproduction . For example , pieces of a parent plant may break off and develop into a whole new plant . Many plants will also grow from a cutting , which may be a leaf , stem , or root cut from a plant . Of course , a plant that is produced ally is genetically identical to the plant from which it came . Why do plants need adaptations to prevent 11 ' water loss ?

ti FIGURE Plant Classification Nonvascular Plants The hundreds of thousands of plants that exist today can be classified as either nonvascular plants or vascular plants . Nonvascular plants are small and live in moist environments . Plan Vascular plants can grow tall and live in diverse habitats . Classifying What are the three groups of vascular plants ?

Classification of Plants Scientists informally group plants into two major nonvascular plants and vascular plants . Figure shows of the major groups of plants living today . Nonvascular Plants Plants that lack a tem of tubes for transporting water and other materials are known as nonvascular plants . Nonvascular plants are growing and do not have roots for absorbing water from the ground . Instead , they obtain water and materials directly from their surroundings . The materials then simply pass from one cell to the next . This means that materials do not travel very far or very quickly . This slow method of transport helps explain why most nonvascular plants live in damp , shady places . Most nonvascular plants have only thin cell walls to provide support . This is one reason why these plants can not grow more than a few centimeters tall . Vascular Plants Plants with true vascular tissue are called GO vascular plants . Vascular plants are better suited to life in dry 33 ) areas than are nonvascular plants . Their INKS . lar tissue solves the problem of transport , moving materials 50 ' Links Plant more quickly and throughout the plant body . Vascular tissue also provides strength , stability , and support Web Code . to a plant . Thus , vascular plants are able to grow quite tall . 3559

Vascular Plants Seedless Vascular Plants , on vascular plums that flower . and produce nods that an surrounded by fruit . The cactus produces brilliantly colored flowers . Wheat has been an important food crop for thousands of years . The grains , or fruits , are ground to make flour . I I , Ir ! Chapter 10 357

Rock containing two plant fossils FIGURE Ancient and Modern Plants Fossils of ancient plants help scientists understand the origin of plants . These fossils are of two plants that lived about 300 million years ago . Notice the similarities between the fossils and day ferns ( top right ) and ( above ) 3680 Origin of Plants Which organisms were the ancestors of plants ?

In search of answers , biologists studied fossils . The oldest plant fossils are about 400 million years old . The provide evidence that even that early , plants already had many adaptations for life on land , including vascular tissue . Better clues to the origin of plants came from comparing the chemicals in modern plants to those in other organisms . In , biologists studied the green pigment chlorophyll , which is found in the of plants . algae . and some bacteria . Land plants and green algae contain the same forms of . This evidence led biologists to infer that ancient green algae were the ancestors of todays land plants . Further of genetic material clearly showed that plants and green algae are very closely related . In fact , some scientists think that green algae should be in the plant kingdom . Complex Life Cycles Plants have complex life cycles that include two stages , the sporophyte stage and the stage . In the sporophyte ( ruh ) stage , the plant produces spores , tiny cells that can grow into new organisms . A spore develops into the plants other stage , called the . In the gametophyte ( guh MEE tuh ) stage , the plant produces sex cells , or gametes . The gametophyte stage produces two kinds of sex cells sperm cells and egg cells . Figure shows a typical plant life cycle . A sperm cell and egg cell join to form a zygote . The zygote then develops into a sporophyte . The produces spores , which develop into the . Then the gametophyte produces sperm cells and egg cells , and the cycle starts again . The sporophyte of a plant usually looks quite different from the gametophyte . i During which stage does a plant produce spores ?

Plant Life Cycle Plants have complex life cycles that consist of two sporophyte stage and the gametophyte stage . Interpreting Diagrams During which stage are sperm and egg cells produced ?

Gametophyte Stage Produces egg cells sperm cells cells section Assessment OD Target Reading Skill Sequencing Events Classifying Would you expect a tall desert Use your cycle diagram to help answer Question plant to be a vascular plant ?

Explain . a . Describing What are the two major stages Reviewing Key Concepts plan life cycle ?

a . Listing List three characteristics of plants . Comparing and Contrasting Describe three ways that plant cells differ from the cells of some other . Predicting How might a plant cell be affected if it lacked ?

Identifying What are adaptations that Sequencing Describe in order the major events in the life of a plant . starting with a zygote . At Home Activity Plants need to survive on land ?

Classifying Plants Look through old magazines Inferring Why is a cuticle a useful adaptation . I . in plants but not in algae ?

and cut out pictures plants . assify plant as vascular or nonvascular . Create a poster of your classification . Present your poster to your family and explain the differences between nonvascular and vascular plants . a . Reviewing How do vascular plants differ from nonvascular plants ?

Explaining Explain why vascular plants are better suited to life in dry areas . Chapter so 359 What characteristics clothe three What characteristics do the three Plants Without Seeds Will Mosses Absorb Water ?

Place 20 of sand into a plastic graduated cylinder . Place 20 of peat moss into a second plastic graduated cylinder . Predict what would happen if you were to pour 10 of water slowly into each graduated cylinder and then wait five minutes . To test your prediction , add 10 of water slowly to the sand . Then add 10 of water to the moss , After five minutes , record your observations . Think It Over Predicting How did your prediction compare with your results ?

What did you learn about moss from this investigation ?

Students know plants and animals have levels of organization for structure and function , ing cells , tissues , organs , organ , and the whole organism . groups of nonvascular plants share ?

groups of seedless vascular plants share ?

Key Terms I rhizoid frond As you hike in the forest , you see ferns along the trail . Near a stream , you see mosses the forest floor , on rocks , and along the banks of the stream . Although ferns and mosses look very erent , they have something in common . Both reproduce without forming seeds . Nonvascular Plants Mosses are a type of seedless plant with no true vascular tissue . are three major groups of nonvascular plants ( mosses , and . These INKS . plants live in moist areas where they can absorb water and Unis ' Plants other nutrients directly from their environment . The watery Visit web ode 01 43 environment enables sperm cells to swim to egg cells during sexual reproduction .

Ar Mosses With more than species . mosses are the most diverse group of nonvascular plants . You have probably seen mosses growing in sidewalk cracks , on tree trunks , and in other damp , shady spots . Figure shows the structure of a moss plant . The familiar green , fuzzy moss is the gametophyte generation of the plant . Structures that look like tiny leaves grow off a small . stemlike structure . Thin , rootlike structures called anchor the moss and absorb water and nutrients from the soil . The sporophyte generation grows out of the . It consists of a slender stalk with a capsule at the end . The capsule contains spores . There are more than species of . are often found growing as a thick crust on moist rocks or soil along the sides of a stream . This group of plants is named for the shape of the plants gametophyte , which looks somewhat like a human liver . Wort is an old English word for plant . have that are too small to see . There are fewer than 100 species of . Unlike mosses or , are seldom found on rocks or tree trunks . Instead . usually live in moist soil , often mixed in with grass plants . are named for the slender . curved structures that grow out of the . These structures are the . What does a hornwort sporophyte look like ?

Moss plants growing on rock FIGURE A Moss Plant A moss gametophyte has stemlike , leaflike , and rootlike structures . Interpreting Diagrams What structures anchor the moss plant ?

Capsule Stalk Sporophyte Gametophyte FIGURE An Ancient Forest Giant ferns , and club mosses dominated ancient forests on Earth . Seedless Vascular Plants Figure shows what an ancient forest on Earth might have looked like 340 million years ago . Among the plants were huge , ferns as well as trees with branches that grew in a series of circles along the trunk . Other trees resembled giant sticks with leaves up to one meter long . When the leaves dropped off . they left scars . These tall , trees were the ancestors of three groups of plants that are alive , tails , and club mosses . They are seedless plants that have vascular tissue . Characteristics of Seedless Vascular Plants Seedless vascular plants share two characteristics . Ferns , and club mosses have true vascular tissue , and they do not produce seeds . Instead of seeds , these plants reproduce by releasing spores . Unlike mosses . seedless vascular plants can grow tall because their vascular tissue provides an tive way of transporting materials . The cells making up their vascular tissue have strong cell walls . fore . vascular tissue also provides vascular plants with strength and stability . Like mosses , seedless vascular plants need to grow in moist surroundings . This is because the plants release spores into their surroundings , where they grow into . When the produce egg cells and sperm cells , there must be enough water available for fertilization .

Frond FIGURE A Fern Plant Fem leaves , or fronds , grow above ground . Most ferns have underground stems in addition to roots . Ferns can reproduce asexually by sending up fronds from the stems . Relating Diagrams and Photos Where are spore cases found an a fern plant ?

Ferns There are more than species of ferns alive today . Like other vascular plants , ferns have true stems , roots , and leaves . The stems of most ferns run horizontally underground . Leaves grow upward from the top side of the stems , while roots grow downward from the bottom of the stems . The roots anchor the fern to the ground and absorb water and nutrients from the soil . These substances enter the root vascular tissue and travel through the tissue into the stems and leaves . Figure shows a fern structure . Notice that the fern leaves , or fronds , are divided into many smaller parts that look like small leaves . The upper surface of each frond is coated with a cuticle that helps the plant retain water . The familiar fern , with its visible fronds , is the sporophyte stage of the plant . On the underside of mature fronds , spores develop in tiny spore cases . Wind and water can carry the spores great distances . If a spore lands in moist , shaded soil , it develops into a . Fern are tiny plants that grow low to the ground . How are seedless vascular plants like mosses ?

Spore cases on undersides of fronds . Ti Activity Examining a Fern . Your teacher will give you a fern plant to observe . Draw a diagram of the plant and label the structures that you see . Use a hand lens to observe the top and lower surfaces of the leaf . Run a finger over both surfaces . With a plastic dropper , add a few drops of water to the top surface of the leaf . Note what happens . Inferring Use your tions to explain how ferns are adapted to life on land . Chapter 10 373

There are very few species of on Earth today . As you can see in Figure 10 , the stems of are jointed . Long , coarse . branches grow in a circle around each joint . Small leaves grow against the stem just above each joint . The whorled pattern of growth somewhat resembles the appearance of a horse tail . The stems contain silica , a gritty substance also found in sand . During colonial times . Americans used the plants to scrub their pots and pans . Another name for is scouring rushes . Club Masses like ferns . club mosses have true stems , roots , and leaves . They also have a similar life cycle . However , there are only a few hundred species of club mosses alive today . mu 10 Do not be confused by the name club mosses . Unlike true and Club Mosses mosses , club mosses have vascular tissue . The plant , which ' em We ' looks a little like the small branch of a pine tree , is sometimes leaves that grow in a circle around . each dub mosses ( right ) look called ground pine or princess pine . Club mosses usually grow like tiny pine nee in moist woodlands and near streams . Inferring Which grow true mosses or club mosses ?

Where do club mosses usually grow ?

Reading , section Assessment ' Skill Academic Words . Comparing and Contrasting In what ways do Which are more or ferns . and club mosses differ from true ?

Explain your answer . mosses ?

In what way are they similar to ?

Inferring Although ferns have vascular tissue , they still must live in moist environments . Explain why . Reviewing Key Concepts a . Describing What two characteristics do mosses , and share ?

Relating Cause and Effect How are these ' two characteristics related ?

In Sue nce Comparing and Contrasting In what ways pug an ( wage a be are mosses , and to put of fem punts for le similar ?

In what ways do they differ ?

yam . numb . the , a . Listing What two characteristics do ferns , gnawing . and club mosses share ?

info of 374 The Characteristics of Seed Plants Standards Focus What the Story ?

Your teacher will give you a hand lens and two different seeds that have been soaked in water . Carefully observe the outside of each seed . Draw what you see . Gently remove the covering of each seed . Then carefully Students know plants and animals have levels of organization for structure and function , ing cells , tissues , organs , organ systems , and the whole organism . What characteristics do seed plants share ?

separate the structures . Use a hand lens to examine them . How do seeds become new Draw what you see . Think It Over Posing Questions Write two questions about the structures in each seed . How could you find out the answers ?

phloem I xylem ' pollen Have you ever planted seeds in a garden ?

If so . then you ' eed may remember how it seemed to take forever before those green shoots emerged . Shortly afterwards , you saw , germination one set of leaves , and then others . Then a may have appeared . Did you wonder where all those plant parts came from ?

How did they develop from one small seed ?

Read on to find out . What Is a Seed Plant ?

The plant growing in your garden was a seed plant . 80 are most of the other plants around you . fact , seed plants outnumber seedless plants by more than ten to one . You eat many seed , peas , and squash , for example . You wear clothes made from seed plants , such as cotton and flax . You may live in a home built from seed oak , pine , or maple trees . In addition , seed plants produce much of the oxygen you breathe . Seed plants share two important characteristics . They have vascular tissue , and they use pollen and seeds to reproduce . In addition , most seed plants have organs that include roots , stems , and leaves . Like seedless plants , seed plants have complex life cycles that include the and the stages . In seed plants , the plants that you see are the . The A A salad of seed plants are microscopic . Chapter 10 375

have strong cell long tubes for carrying water . Freon 11 Phloem and Xylem The stems of vascular plants contain bundles of phloem and xylem . Observing How is the structure of vascular tissue adapted for transporting materials ?

FIGURE 12 Morning Glory Pollen These greatly magnified grains of pollen contain cells that will develop into sperm . 316 are living . They to transport in the leaves to all parts of the plant . Vascular Tissue Most seed plants live on land . Recall that land plants face many challenges , including standing upright and supplying all their cells with food and water . Like ferns , seed plants meet these two challenges with vascular tissue . The thick walls of the cells in the vascular tissue help support the plant body . In addition , vascular tissue transports food , water , and nutrients throughout the plant . There are two types of vascular tissue . Figure 11 shows these two tissues . Phloem ( urn ) is the vascular tissue through which food moves When food is made in the leaves . it enters the phloem and travels to other parts of the plant . Water and minerals , on the other hand , travel in the vascular tissue called xylem ( lum ) Roots absorb water and minerals from the soil . These materials enter the root xylem and move upward into the stems and leaves . Pollen and Seeds Unlike seedless plants , seed plants can live in a wide variety of environments . Recall that seedless plants need water in their surroundings for fertilization to occur . Seed plants do not need water for sperm to swim to the eggs . Instead , seed plants produce , tiny structures that contain the cells that will later become sperm cells . Pollen delivers sperm cells near to the eggs . After cells fertilize the eggs , seeds develop . A seed is a structure that contains a young plant inside a protective covering . Seeds protect the young plant from drying out .

How Seeds Become New Plants All seeds share several important similarities . Inside a seed is developed plant . If a seed lands in an area where conditions are favorable , the plant sprouts out of the seed and begins to grow . Seed Structure A seed has three main embryo , stored food , and a seed coat . The young plant that develops from the zygote , or fertilized egg , is the embryo ( em BREE oh ) The embryo already has the beginnings of roots , stems , and leaves . In the seeds of most plants , the embryo stops growing when it is quite small . When the embryo begins to grow again , it uses the food stored in the seed until it can make its own food by photosynthesis . The embryo has one or more seed leaves , or ( uh LEED ) In some seeds , food is stored in the dons . In other seeds , food is stored outside the embryo . in sue called endosperm . Figure 13 compares the structure of corn , bean , and pine seeds . The outer covering of a seed is called the seed coat . Some familiar seed coats are the skins on lima beans and peanuts . The seed coat acts like plastic wrap , protecting the embryo and its food from drying out . This allows a seed to remain inactive for a long time . In many plants , the seeds are surrounded by a ture called a fruit . a cotyledon ?

Seed coat ( For Links on seed plans Visit Web Code more 13 Seed Structure The structures of three different seeds are shown here . In bean seeds , the cotyledon stores food . In corn and pine seeds . food is stored in endosperm . Inferring How is the stored food used ?

Chapter 10 an Seed Dispersal After seeds have formed , they are usually scattered , sometimes far from where they were produced . The ' scattering of seeds is called seed dispersal . Seeds are dispersed in Seed ?

many ways . One method involves other organisms . For example , some animals eat fruits , such as cherries or grapes . The seeds inside the fruits pass through the animal digestive system and are deposited in new areas . Other seeds are enclosed in structures that hook onto an animal fur or a persons clothes . The structures then fall of ?

the fur or clothes in a new area A second means of dispersal is water . Water can disperse seeds that fall into oceans and rivers . A third dispersal method involves wind . Wind disperses lightweight seeds that often have structures to catch the wind , such as those of dandelions 055995 ?

Wind and maple trees . Finally , some plants eject their seeds in a way ' that might remind you of popping popcorn . The force scatters with parachutes . the seeds in many directions . 14 Seed Dispersal The seeds of these plants are enclosed in fruits with adaptations that help them disperse . palm A Dispersal by animals fruits 378

Germination After a seed is dispersed , it may remain inactive for a while before it germinates . Germination ( muh NAY shun ) occurs when the embryo begins to grow again and pushes out of the seed . Germination starts when the seed absorbs water from the environment . Then the embryo uses its stored food to grow . As shown in Figure 15 , the embryo roots grow ward . Then its stem and leaves grow upward . Once you can see a plant leaves , the plant is called a seedling . Environmental conditions , such as ture and moisture , must be just right in order for a seed to germinate . For example , some seeds will germinate only after a cold winter or after being exposed to a . If environmental tions are not suitable for germination , some seeds may remain inactive for years . A seed that is dispersed far from its parent plant usually has a better chance of survival . When a seed does not have to compete with its parent for light , water , and nutrients , it has a better chance of becoming a seedling . what conditions are needed in ) order for germination to begin ?

Section Vocabulary Skill Academic Words Why is the way in which a seed is dispersed important ?

Use the word survival in your answer . Reviewing Key Concepts a . Reviewing What two characteristics do all seed plants share ?

Relating Cause and Effect What tics enable seed plants to live in a wide variety of environments ?

Explain . a . Listing Name the three main parts of a seed . Sequencing What steps must occur for a seed to grow into a new plant ?

List the steps in sequence . Assessment FIGURE 15 Germination The embryo in this peanut seed uses its stored food to germinate . First , the embryo roots grow downward . Then , its stem and leaves begin to grow upward . Reading , Writing Applying Concepts If a cherry seed were to take root right below its parent tree , what three challenges might the cherry seedling face ?

in Science . Chapter 10 379 Students know that liberate energy for the work that cells do and that capture sunlight energy for photosynthesis . Students know plants and animals have levels of for structure and function , ing cells , tissues , organs , organ , and the whole organism . What are the main functions of roots , stems , and leaves ?

Key Terms root cap cambium transpiration FIGURE 16 Root Systems Some plants have fibrous roots while others have . Roots , Stems , and Leaves Standards Which Plant Part Is It ?

Carefully observe the items of food your teacher gives you . Make a list of the food items . For each food item , write the name of the plant , stem , or which you think it is obtained . Think It Over Classifying Classify the items into groups depending on the plant part from which the food is obtained . Compare your groupings with those of your classmates . Chances are you eaten carrots , potatoes , and lettuce . But how much do you know about these common seed plants ?

For example , did you know that when you eat a carrot , you are ing a root ?

A potato is actually a stem . And lettuce leaves have many adaptations for photosynthesis . The structure of roots , stems , and leaves varies greatly among seed plants . However . they perform similar functions critical to the plants survival .

Roots Have you ever tried to pull a dandelion plant out of the soil ?

It not easy , is it ?

That is because most roots are good anchors . Roots have three main functions . Roots anchor a plant in the ground , absorb water and minerals from the soil , and sometimes store food . The more root area a plant has , the more water and minerals it can absorb . Types of Roots The two main types of root systems are root systems and taproot systems . A root system consists of many similarly sized roots that form a dense , tangled mass . Plants with roots take much soil with them when you pull them out of the ground Lawn grass , corn , and onions have root systems . In contrast . a taproot system has one long , thick main root . Many smaller roots branch off the main root . A plant with a taproot system is hard to pull out of the ground . Carrots , dandelions , and cacti have . The Structure of a Root Figure 17 shows the structure of a typical root . Notice that the tip of the root is rounded and is covered by a structure called the root cap . The root cap protects the root from injury from rocks as the root grows through the soil . Behind the root cap are the unspecialized cells that into new root cells . Root hairs grow out of the root surface . These tiny hairs can enter the spaces between soil particles , where they absorb water and minerals . By increasing the surface area of the root that touches the soil , root hairs help the plant absorb large amounts of water and other substances . Locate the vascular tissue in the center of the root . The water and nutrients that are absorbed from the soil quickly move into the xylem . From there , these substances are ported upward to the plant stems and leaves . Phloem transports food manufactured in the leaves to the root . The root tissues may then use the food for growth or store it for Surface cells future use by the plant . Root Structure A root structure is adapted for absorbing Whit ' he ' I of water and minerals from the soil . root cap ?

Relating Cause and Effect How do root hairs help absorb water and minerals ?

chapter 10 331 mun 18 Structure of a Stem Leafs are attached at nodes along the stem . Buds are also at the nodes . Buds can develop into new branches , leaves , or flowers . 3820 FIGURE 19 A Herbaceous Stem Herbaceous stems , like those on these , are often soft . The inset shows the inner structure of one type of herbaceous stem . The bundles of vascular tissue in this stem are arranged in a ring . Stems A plant stem has several main functions . The stem produces branches , leaves , and . It carries substances between the plant roots and leaves . The stem also provides support for the plant and holds up the leaves so they are exposed to the sun . In addition , some stems store food . For example , a potato is a stern that is adapted to store food . The structure of a Stem Stems consist of vascular tissue as well as many other supporting cells . Bundles of xylem and phloem run all the way up from the roots to the leaves . Depending on the type of plant , the bundles of vascular tissue can be scattered randomly throughout the stem , or arranged in rings within the stem . In most plants , a stem has regions called nodes where leaves are attached . Buds are found at the nodes . Buds contain tissue that can differentiate into new branches , leaves , or . Figure 19 shows the structure of a typical stem . Stems can either be herbaceous ( hur BAY ) or woody . Herbaceous Stems You are probably familiar with many plants that have herbaceous stems . Daisies , geraniums , and ley have herbaceous stems . Herbaceous stems contain no wood and are often soft . Figure 19 shows the inner structure of a stem with one type of vascular tissue arrangement .

Woody Stems As you can see in Figure 20 , a woody stem contains several layers of tissue . The outermost layer is bark . Bark includes an outer protective layer and an inner layer of living phloem . which transports food through the stem . Next is a layer of cells called the cambium ( KAM bee um ) which divide to produce new phloem and xylem . it is xylem that makes up most of what you call is active xylem that transports water and minerals through the stem . The older . darker , heartwood is inactive but provides support . Notice the pattern of circles that looks something like a target in woody stems . These circles are called annual rings because they represent a tree yearly growth . Annual rings are made of xylem . Xylem cells that form in the spring are large and have thin walls because they grow rapidly . They I produce a wide . light brown ring . Xylem cells that form in the summer grow slowly and , therefore , are small and have thick walls . They produce a thin , dark ring . One pair of light and dark rings represents one years growth . You can mate a tree age by counting its annual rings . The width of a annual rings can also provide 20 important clues about past weather conditions . such as A woody stem ' fall . in rainy years , more xylem is produced . so the trees I , woody stem is made up , annual rings are wide . In dry years , rings are narrow . I many layers . The layers of xylem form annual rings that can reveal the age of ! 73 the tree and the growing it 01 stem perform ?

has experienced . Interpreting Diagrams Where is the cambium located ?

I , lad ( Protects the cells inside ) . noun 21 The Structure of a Leaf A leaf in food A ' factory . Each structure helps comm water loss the leaf produce food . Xylem The xylem carries . water absorbed by . Widely spaced cells We plant roots allow carbon dioxide up into the teat to reach cells for photosynthesis , and oxygen to into the air . The food when the tiny pores called stomata open , carbon dioxide made du . enters enters the leaf white oxygen the and travels and water vapor move out . throughout the plant . Leaves leaves vary greatly in size and shape . Pine trees , for example , have leaves . Birch trees have flat rounded leaves with jagged edges . Whatever their shape , leaves play an tant role in a plant . The structure of leaves is adapted for capturing the surfs energy and carrying out photosynthesis . The Structure of a Leaf If you were to cut through a leaf and look at the edge under a microscope , you would see the structures in Figure 21 . The leaf top and bottom ers protect the cells inside . Between the layers of cells are veins that contain xylem and phloem . The surface layers of the leaf have stomata , the pores that open and close to control when gases enter and leave the leaf . The Leaf and Photosynthesis The structure of a leaf is ideal for carrying out photosynthesis . The cells that contain the most are located near the leaf upper surface , where they get the most light . Chlorophyll in the traps the suns energy . Fan More on leaves Web Code

Carbon dioxide enters the leaf through open stomata Water , which is absorbed by the plant roots , travels up the stem to the leaf through the xylem . Recall that during photosynthesis , sugar and oxygen are produced from the carbon dioxide and water . Oxygen passes out of the leaf through the open stomata . The sugar enters the phloem and then travels throughout the plant . The many chemical reactions of photosynthesis can be summarized by this equation light energy carbon dioxide water sugar oxygen Controlling Water Loss Because such a large area of a leaf is exposed to the air , water can quickly evaporate , or be lost , from a leaf into the air . The process by which water evaporates from leaves is called transpiration ( tran RAY shun ) A plant can lose a lot of water through transpiration . A plant , for example , can lose almost liters of water on a hot summer day . Without a way to slow down the process of Freon 22 spiration , a plant would sh rivel up and die . Fortunately , plants have ways to slow down transpiration . a ( in la tain ' th st Th ( ne ay a wa ma . wand stomata often close when leaves start to dry out . Figure 22 shows open and closed stomata . How does water get into a leaf ?

section Assessment Relating Cause and Effect What gases enter and exit when the stomata open ?

Vocabulary Skill Academic Words a . Reviewing What process are How ?

does get from a plant leaves to its leaves adapted to cam , om ?

US answer . Relating Cause and Effect How are stomata ( Reviewing Key Concepts adapted to carry out this process ?

Predicting Water lilies live in fresh water , with leaves that on the surface . Where would you expect to the stomata on the leaves of water lilies ?

a . Listing Name three main functions of roots . Explaining How do root hairs aid in the function of roots ?

Inferring Weeds have taken over your garden . While removing the weeds . you notice that the roots grow wry deep . How do you think the ' weeds roots contribute to their success in your garden ?

Identifying What roles do stems play ?

Sequencing List in order the of tissue within a woody stem . moving from the center of the stem to the outermost layer . Plant all With a family member . 90 on a plant walk in your neighborhood . Look for different kinds of seed plants . Describe the adaptations in their roots , stems , and leaves that enable the plants to survive . Chapter 10 385

Design Your Own Lab Eye on Photosynthesis Problem What raw materials and conditions are involved in photosynthesis ?

skills Focus observing , controlling variables , designing experiments Materials plants water ( boiled , then cooled ) Container sodium bicarbonate solution test tubes wax pencil lamp ( optional ) Procedure Observing Photosynthesis . Use a wax pencil to label two test tubes and . Fill test tube with sodium bicarbonate solution . Sodium bicarbonate provides a source of carbon dioxide for photosynthesis . Fill the container about three fourths full of sodium bicarbonate solution . Hold your thumb over the mouth of test tube . Turn the test tube over , and lower it to the bottom of the container . Do not let in any air . If , repeat this step so that test tube contains no air pockets . CAUTION Glass test tubes are fragile . Handle the test tubes carefully . Do not touch broken glass . Fill test tube with sodium bicarbonate tion . Place an plant in the tube with the cut stem at the bottom . Put your thumb over the mouth of the test tube , and lower it into the container without letting in any air . Wash your hands . Place the container with the two test tubes in bright light . After a few minutes , examine both test tubes for bubbles . 3866 . if bubbles form in test tube observe the stem to see if it is producing the bubbles . The bubbles are oxygen bubbles . The production of oxygen signals that synthesis is taking place . Leave the setup in bright light for 30 minutes . Observe what happens to any bubbles that form . Record your tions . Is Carbon Dioxide Needed for Photosynthesis ?

Your teacher will provide a supply of water that has been boiled and then cooled . ing removes gases that are dissolved in the water , including carbon dioxide . Based on what you learned in Part , design an experiment to show whether or not carbon dioxide is needed for photosynthesis . Obtain your teacher approval before ing out your experiment . Record all your observations .

PART What Other Conditions Are Needed for Photosynthesis ?

10 . Make a list of other conditions that may affect photosynthesis . For example , think about factors such as light , the size of the plant , and the number of leaves . Choose one factor from your list . Then design an experiment to show how the factor affects photosynthesis . Obtain your approval before carrying out your experiment . Record all your observations . Analyze and conclude . Observing What process produced the you observed in Part ?

In what cell organelle did this process occur ?

Controlling Variables In Part , what was the purpose of test tube ?

Designing Experiments For the experiments you carried out in Parts and , identity the manipulated variable and the responding variable . Explain whether or not your ments were controlled experiments . Drawing Conclusions Based on your results in Part , is carbon dioxide necessary for photosynthesis ?

Posing Questions What question about photosynthesis did you explore in Part ?

What did you learn ?

Communicating In a paragraph , summarize what you learned about photosynthesis from this investigation . Support your with data you collected during your experiments . More to Explore A small animal in a closed container will die , even if it has enough water and food . A small animal in a closed container with a plant , water , and food might live . Use what you have learned from this experiment to explain these facts . 387

009 ( A Standards Focus Students know the between the life cycles and reproduction methods of sexual and asexual organisms . Students know the and processes by which ering plants generate pollen , seeds . and fruit . What are the characteristics of and how do they reproduce ?

What are the characteristics of angiosperms ?

How do reproduce ?

What are the two types of ?

Key Terms gymnosperm cone ovule pollination angiosperm flower sepal petal I stamen pistil ovary fruit monocot dicot For Links on Web Code 3880 , Reproduction in Seed Plants , Standards What Is a Fruit ?

Your teacher will give you three ent fruits that have been cut in half . Use a hand lens to carefully observe the outside of each fruit . For each fruit , record its color , shape , size , and other external features . Record your observations in your notebook . Carefully observe the structures inside the fruit . Record your observations . Think It Over Forming Operational Definitions Based on your observations , how would you define the term fruit ?

Here a question for you What do pine cones and apples have in common ?

The answer is that they are both the parts of seed plants . Pine trees and apple trees are both seed plants . However , they belong to two different groups of seed and angiosperms . Pine trees belong to the group of seed plants known as . A gymnosperm ( nuh ) is a seed plant that produces naked seeds . The seeds of are referred to as naked because they are not enclosed by a protective fruit . All produce naked seeds . In addition , many have or scalelike leaves , and root systems . are the oldest type of seed plant . According to fossil evidence , first appeared on Earth about 360 million years ago . Fossils also indicate that there were many more species of on Earth in the past than there are today . Four groups of exist today .

FIGURE 23 Types of are the oldest seed plants . conifers , and are the only groups that exist today . A About 175 million years ago , the majority of plants were . Today , SY ) grow mainly in tropical and subtropical areas . look like palm trees with cones . A cycad cone can grow as large as a football . Conifers Conifers ( uh ) or plants , are the largest and most diverse group of sperms today . Most conifers , such as pines . sequoias , and , are that keep their leaves . or needles , When needles drop off , they are replaced by new ones . also grew hundreds of millions of years ago . But today , only one species of ginkgo , Ginkgo , exists . It probably survived only because the Chinese and Japanese cared for it in their dens . Today , ginkgo trees are planted along city streets because they can tolerate air pollution . NEE tuh ) live in hot deserts and in tropical rain forests . Some are trees , some are shrubs , and others are vines . The chia shown in Figure 23 grows in the deserts of West Africa and can live for more than years . im ) What are the four types of ?

Ginkgo A Ginkgo biloba The Scoop on Cones In this activity , you will observe the structure of a female cone . Use a hand lens to look closely at the female one . Gently shake the ver a piece of white paper . Observe what happens . Break off one scale from the cone . Examine its base . If the scale contains a seed , remove the seed . With a hand lens , examine the seed from Step or examine a seed that fell on the paper in Step . Wash your hands . Inferring How does the structure of the cone protect the seeds ?

3906 Gymnosperm Life Cycle Most have reproductive structures called cones . Cones are covered with scales . Most produce two types of cones male cones and female cones . Usually , a single plant produces both male and female cones . In some types of , however , individual trees produce either male cones or female cones . A few types of sperms produce no cones at all . In Figure 24 , you can see the male and female cones of a Ponderosa pine . Male cones produce tiny grains of male gametophyte . Pollen contains the cells that will later become sperm cells . Each scale on a male cone produces sands of pollen grains . The female gametophyte develops in structures called . An ovule ( OH ) is a structure that contains an ovum , or egg cell . Female cones contain at least one ovule at the base of each scale . After fertilization occurs , the ovule develops into a seed You can follow the process of gymnosperm reproduction in Figure 24 . First , pollen falls from a male cone onto a female cone . In time , a sperm cell and an egg cell join together in an ovule on the female cone . After fertilization occurs , the seed develops on the scale of the female cone . The transfer of pollen from a male tive structure to a female reproductive structure is called pollination . In , wind often carries the pollen from the male cones to the female cones . The pollen collects in a sticky substance produced by each ovule . Fertilization Once pollination has occurred , the ovule closes and seals in the pollen . The scales also close , and a cell fertilizes an egg cell inside each ovule . The fertilized egg then develops into the embryo part of the seed . Seed Development Female cones remain on the tree while the seeds mature . As the seeds develop , the female cone increases in size . It can take up to two years for the seeds of some to mature . Male cones , however , usually fall off the tree after they have shed their pollen . Seed Dispersal When the seeds are mature , the scales open . The wind shakes the seeds out of the cone and carries them away . Only a few seeds will land in suitable places and grow into new plants . i What structure produces pollen ?

FIGURE 24 The Cycle of a Gymnosperm Ponderosa pines have a typical life cycle for a gymnosperm . Follow the steps of pollination . fertilization , seed development , and dispersal in the pine tree . Interpreting Diagrams Where do the pine seeds develop ?

A pine tree GA A male cone produces pollen grains , which produces male contain cells that will mature into sperm cells . and female cones . Scale on female cone Each scale on In time , a female cone two egg cells has two form inside at its base . each ovule , The wind scatters pollen grains . Some become trapped In a sticky substance The ovule closes , and a pollen grain produces a Wind disperses the pine seeds A seed ovule develops into tube the ' A grows into a seedling reed egg and then into a tree . Se em Other parts of the ovule ' the 999 develop into the seed coat and the seed stored food . Chapter 10 391 produced by the ovule .

FIGURE 25 Rafflesia plants grow in the jungles of Southeast Asia . The giant flowers measure about meter across and weigh about kilograms ! Classifying What kind of seeds do Rafflesia plank seeds or seeds enclosed in fruits ?

392 Angiosperms You probably associate the word with a plant growing in a garden . You certainly would think of something that smells like rotting meat . But that exactly what the corpse , or rafflesia , smells like . belongs to the group of seed plants known . An angiosperm ( AN jee uh ) is a plant . All angiosperms share two important traits . First , they produce . Second , in contrast to , which produce uncovered seeds , angiosperms produce seeds that are enclosed in fruits . Angiosperms live almost everywhere on Earth . They grow in frozen areas in the Arctic , tropical jungles , barren deserts , and at the ocean edge . gigging , Where do live ?

The Structure of Flowers Flowers come in all sorts of shapes , sizes , and colors . But , despite their differences , all have the same . A is the reproductive structure of an angiosperm . Figure 26 shows the parts of a typical . As you read about the parts , keep in mind that some lack one or more of the parts . For example , some have male structures , but no female reproductive structures . Other lack petals . Sepals and Petals When a is still a bud , it is enclosed by structures called sepals ( SEE ) Sepals protect the developing and are often green in color . When the sepals fold back , they reveal the colorful , petals . The petals are generally the most colorful parts of a . The shape , size , and number of petals vary greatly from to . Stamens the petals are the flower male and female reproductive structures . The stamens ( STAY ) are the male reproductive structures . Locate the stamens inside the in Figure 26 . The thin stalk of the stamen is called the . Pollen is produced in the anther , at the top of the . The connects the anther to the base of the , which is called the receptacle .

! are the female The Structure of a . of A of Like flowers lily contains both i sticky 559 , gender mu dyed in male and female reproductive structures . Me , and , and . Stamens Stamens are the male reproductive parts of . stamen Pollen is produced In the amber . at the top of the filament . Sepals are the smell , 11 sepals , the Receptacle most colorful ports of ' developing a flower . are attracted by the petals colors . Go The female parts , or ( PIS ) are found in the center of most . Some have two or more others have only one . The sticky tip of the pistil is called the Visit Web Code stigma . A slender tube , called a style , connects the stigma to a hollow structure at the base of the . This hollow structure is the ovary , which protects the seeds as they develop . An ovary contains one or more . Pollinators The colors and shapes of most petals and the scents produced by most attract insects and other animals . These organisms carry pollen from one to another . include birds , bats , and insects such as bees and . The you read about at the beginning of the tion is pollinated by . The are attracted by the strong , smell . What are the male and female parts of a flower ?

ones mam Angiosperm Life Cycle This bee is getting dusted with You can follow the life cycle of an angiosperm in Figure yellow 05 it drinks nectar First , pollen falls on a stigma . In time , the sperm from the flower . Observing On you observe pollen grains ?

develops into the embryo part of the seed . Pollination A is pollinated when a grain of pollen falls on the stigma . Like . some angiosperms are pollinated . But most angiosperms rely on birds , bats . or insects for pollination . Nectar , a food . is located deep inside a . When an animal enters a to obtain the nectar . it against the and becomes coated with pollen . Some of the pollen can drop onto the stigma as the I , mal leaves the . The pollen can also be brushed onto the stigma of the next the animal visits Fertilization If the pollen falls on the stigma of a similar plant , fertilization can occur . A pollen grain produces a pollen tube that grows through the style into the ovule , within the ovary at the base of the . The pollen tube provides a path for the sperm of the pollen tube down to the egg cell . A sperm cell then joins with an egg cell , and the zygote begins to develop into the seed embryo . Other parts of the ovule develop into the rest of the seed . Fruit Development and Seed Dispersal As the seed develops after fertilization , the ovary changes into a ripened ovary and other structures that enclose one or more seeds . Apples and cherries are fruits . So are many foods you usually call vegetables , such as tomatoes and squash . Fruits are the means by which angiosperm seeds are dispersed . Animals Ficus 28 that eat fruits help to disperse their seeds . Fruits The seeds of are a ! i What part develops Into a fruit ?

enclosed in fruits , which protect and help disperse the seeds . 3940 29 The Life Cycle of an Angiosperm All angiosperms have a similar life cycle . Follow the steps of pollination , fertilization , seed development , and dispersal in this apple tree . Interpreting What plant part does the ovule develop into ?

apple tree The cells in the anther produces flowers . produce pollen grains . Pollen grains are trapped on the stigma Inside the ovary , an egg cell is produced in each ovule . I Pollen tube Sperm cells , The pollen grain produces a seed grows pollen tube that grows into into a new plant . the ovule . A sperm cell moves through the pollen tube and fertilizes the egg cell . The ovary and other The ovule develops into a seed . structures develop into The fertilized egg becomes the a fruit that encloses seed embryo . Other parts of the seeds . The fruit the ovule develop into the seed helps in seed dispersal . coat and the seed stored food . Chapter 10 395

tissue . and the number 30 and and differ in the number of , the pattern of veins and vascular of petals . Interpreting Tables Comparing and One cotyledon Two How do monocot and dicot leaves differ ?

Branching veins Parallel veins Bundles of Bundles of vascular tissue vascular tissue scattered arranged in throughout stem a ring Multiples Is a flower with petals a monocot ?

To answer this question . you need to mine if is a multiple of . A number is a multiple of if there is a nonzero whole number that , when multiplied by , gives you that number . In this case , is a multiple of because you can multiply ( a nonzero whole number ) by to get . Therefore , a with petals is a monocot . other multiples of include and 12 . Practice Problem Which of these numbers are multiples of ?

10 , 12 , 16 Flower parts in threes Flower parts in fours or fives Types of Angiosperms Angiosperms are divided into two major groups and . Cot is short for cotyledon . Recall that in some seeds , the cotyledon , or seed leaf , provides food for the embryo . Mano means one and di means are angiosperms that have only one seed leaf . on the other hand , produce seeds with two seed leaves . In Figure 30 , you can compare the characteristics of and . Grasses , including corn , wheat , and rice , and plants such as lilies and tulips are . The of a monocot usually have either three petals or a multiple of three petals . usually have long , slender leaves with veins that run parallel to one another like train rails . The bundles of vascular tissue in monocot stems are usually scattered throughout the stem . include plants such as roses and violets , as well as dandelions . Both oak and maple trees are , as are food plants such as beans and apples . The of often have either four or petals or multiples of these numbers . The leaves are usually wide , with veins that branch many times . Dicot stems usually have bundles of vascular tissue arranged in a ring . Reading How do the petals of and differ in ' number ?

Seed Plants in Everyday Life Products from seed plants are all around you . sperms , especially conifers , provide useful products such as paper and the lumber used to build homes . Conifers are also used to produce turpentine , the rayon in clothes , and the rosin used by baseball pitchers , gymnasts , and musicians . Angiosperms are an important source of food , clothing , and medicine for other organisms . animals eat various parts of plants , including stems , leaves , buds , and . People eat vegetables , fruits . and cereals , all of which are angiosperms . People also make clothing and many other products from angiosperms . For example , cotton come from ton plants The sap of rubber trees is used to make , 31 her for tires and other products . The wood of maple , cotton sous cherry . and oak trees is often used to make furniture . such as Comm Plants . provide many important products . Reading What are two products made from Cotton seeds , which develop in fruits ' 57 called , are covered with fibers that are manufactured into cotton fabric . Assessment Target Reading Skill Sequencing Events Use Name the two major groups of your sequence diagram to help answer Question angiosperms . Reviewing Key . Comparing and Contrasting How do the . seeds , leaves . stems , and of these a . Listing What characteristics do all MO groups differ ?

sperms share ?

What other characteristics do classifying A plan leaves have parallel many have ?

Describing What is a cone ?

What role do ) cones play in gymnosperm reproduction ?

Sequencing describe the steps in the reproduction of a gymnosperm . a . Reviewing What two characteristics do an a Share ?

Multiples Which of the following numbers Identifying What is the function of an are multiples of 37 of the numbers angiosperm ?

are multiples of ?

a . Reviewing On what part of a must pollen land for pollination to occur ?

12 15 ' he in . Multiples Suppose you found a flower with ?

a 12 petals . Would you know from the number of petals whether the flower is a monocot or a dicot ?

Explain . Chapter 10 391 A Close Look at Flowers . Problem What is the function of a flower , and what roles do its different parts play ?

Skills Focus observing , inferring , measuring Materials paper towels scalpel plastic dropper tape hand lens water microscope metric ruler slide lens paper large flower Procedure The Outer Parts of the Flower . Tape four paper towel sheets on your work area . obtain a flower from your teacher . While handling the flower gently , observe its shape and color . Use the ruler to measure it . Notice whether the petals have any spots or other markings . Does the flower have a scent ?

Record your observations with sketches and descriptions . Observe the sepals . How many are there ?

How do they relate to the rest of the flower ?

Hint The sepals are often green , but not always . Record your observations . Use a scalpel to carefully cut off the sepals without damaging the structures beneath them . CAUTION Scalpels are sharp . Cut in a direction away from yourself and others . Observe the petals . How many are there ?

Are all the petals the same , or are they different ?

Record your observations . 39 ! The Male Part of the Flower Carefully pull off the petals to examine the male part of the flower . Try not to damage the structures beneath the petals . Observe the stamens . How many are there ?

How are they shaped ?

How tall are they ?

Record your observations . Use a scalpel to carefully cut the stamens away from the rest of the flower without damaging the structures beneath them . Lay the stamens on the paper towel . Obtain a clean slide and . Hold a stamen over the slide , and gently tap some pollen grains from the anther onto the slide . Add a drop of water to the pollen . Then place the over the water and pollen . Observe the pollen under both the objective and the objective of a microscope . Draw and label a pollen grain .

The Female Part of the Flower to . Use a scalpel to cut the pistil away from the rest of the . Measure the height of the pistil . Examine its shape . Observe the top of the pistil . if that surface will stick to and lift a tiny piece of lens paper . Record your observations . 11 . Lay the pistil onthe paper towel . Holding it at its base , use a scalpel to cut the til in half at its widest point , as shown in the diagram below . Cut away from your . How many compartment do you see ?

How many do you see ?

Record your observations . Analyze and conclude . Observing Based on your observations , describe how the sepals , petals , stamens , and of a are arranged . Inferring How are the sepals , petals , stamens , and pistil involved in the function of this ?

Measuring Based on your measurement of the heights of the pistil and stamens , how do you think the flower you examined is pollinated ?

Use additional observations to support your answer . Classifying Did you any patterns in the number of sepals , petals , stamens , or other structures in your ?

if so , that pattern . Is your flower a monocot or a dicot ?

Communicating Write a paragraph ing all you can learn about a plant by ing one of its . Use your observations in this lab to support your conclusions . More to Explore Some kinds of flowers do not have all the parts found in the in this lab . Obtain a different flower . Find out which parts that has , and which parts . if any , are missing . Obtain your teacher permission before carrying out your investigation .

Chapter 10 The Plant Kingdom Key Concepts Nearly all plants are autotrophs . All plants are multicellular with cell walls . land plants must have ways to obtain water and other nutrients from their surroundings , retain water , transport materials in their bodies , support their bodies , and reproduce . Scientists informally group plants as nonvascular plants and vascular plants . Plants have complex life cycles that include the sporophyte stage and the gametophyte stage . Key Terms cuticle vascular plant vascular tissue sporophyte zygote gametophyte nonvascular plant Plants Without Seeds Key Concepts Mosses , and are growing plants that live in moist areas where they can absorb water and other nutrients . Ferns , and club mosses have true vascular tissue and do not produce seeds . They reproduce by releasing spores . Key Terms rhizoid 45 Characteristics of Seed Plants Key Concepts Seed plants have vascular tissue and use pollen and seeds to reproduce . If a seed lands in an area where conditions are favorable , it can begin to develop into a plant . frond Key Terms phloem embryo xylem cotyledon pollen germination seed 4000 Study Guide . The structure of plants enables them to obtain water and nutrients . I Idea food , grow . develop , and reproduce . Roots , Stems , and Leaves Key Concepts , Roots anchor a plant , absorb water and minerals , and sometimes store food . The stem carries substances between the plants roots and leaves . The stem also provides support for the plant and holds up the leaves so they are exposed to the sun . A leaf structure is adapted for capturing the sun energy and carrying out photosynthesis . Key Terms root cap Cambium transpiration Reproduction in Seed Plants Key Concepts . All produce naked seeds . In addition , many have or scalelike leaves . and roots . During gymnosperm reproduction , pollen falls from a male cone onto a female cone . In time , sperm and egg cells join in an ovule on the female cone . All angiosperms produce and fruits . All function in reproduction . During angiosperm reproduction . pollen falls on a flower stigma . In time , sperm and egg cells join in the ovule . are divided into two major groups and . Key Terms gymnosperm petal cone stamen ovule pistil pollination ovary angiosperm fruit monocot sepal dicot

Review and Assessment , Target Reading Skill To review part of Section , copy the sequence diagram at right , which shows the main events in the life cycle of angiosperms . flowers I For Visit Web Code Angiosperm Life Cycle Seeds develop within fruit , Reviewing Key Terms Choose the letter of the best answer . The waxy , waterproof layer that covers leaves is called the zygote . cuticle . frond . cambium . You see a fuzzy , green moss growing at the base of a tree . To which generation does this familiar structure belong ?

frond rhizoid sporophyte . The leaves of ferns are called . fronds . cuticles . The process by which a seed sprouts is called pollination . fertilization . dispersal . germination . Which of the following is the male part of a flower ?

pistil stamen petal Complete the following sentences so that your answers clearly explain the key terms . Water from the soil can reach the highest branches of a tall tree because the tree has vascular tissue , which is . The rootlike of a moss plant are structures that serve to . On a hot day , a plant can dry out due to transpiration , the process by which . After fertilization . an ovule develops into a seed , which is 10 . For fertilization to occur , pollen must reach the pistil , which is Writing in Science ed , i Chapter 10 401

Review and Assessment Checking Concepts 11 . What are three plant organs ?

12 . Name one adaptation that distinguishes plants from algae . in what ways do mosses and club mosses differ from each other ?

in what ways are they similar ?

14 . Describe four different ways that seeds can be dispersed . Explain the role that stomata play in leaves . 16 . Describe the structure of a female cone . What role does a fruit play in an angiosperm life cycle ?

Thinking Critically 18 . Comparing and Contrasting How does the sporophyte generation of a plant differ from the gametophyte generation ?

19 . Applying Concepts A friend tells you that he has seen moss plants that are about meters tall . Is your friend correct ?

Explain . 20 . Relating Cause and Effect When a strip of bark is removed all the way around the trunk of a tree , the tree dies . Explain why . 21 . Predicting Pesticides are designed to kill harmful insects . Sometimes . however , pesticides kill helpful insects as well . What could this have on angiosperms ?

22 . Classifying Which of the plants below is a monocot ?

Which is a dicot ?

Explain your conclusions . 4020 Math Practice 23 . Multiples Use what you know about multiples to which flower is a and which is a dicot a with nine petals a with eight petals . Explain . Applying Skills Use the data in the graph below to answer Questions . A scientist measured in an ash tree over an period . She also measured how much water the tree roots took up in the same period . and wan uptake Rate ( grams per hour ) 24 . Interpreting Data At what time is the rate of transpiration highest ?

At what time is the rate of water uptake highest ?

25 . Inferring Why do you think the transpiration rate increases and decreases as it does during the period ?

25 . Drawing Conclusions Based on the graph . what is one conclusion you can reach about the pattern of water loss and gain in the ash tree ?

Standards Investigation Performance Assessment Design a poster that shows the results of your investigation . You may wish to use a cycle diagram to show the main events in the plants life . What new did you learn about seed plants by doing this investigation ?

Standards Practice at Choose the letter of the best answer . Based on the diagram below , which of the . The diagram below shows the parts of a . following statements about a plant life cycle In which part is pollen produced ?

is true ?

A part A part A Plants spend part of their lives producing part spores . part Flam Spend the . Which would a student expect to when sperm and egg cells examining a dicot ?

A zygote develops into the A one cotyledon stage of the plant parts in multiples of threes an of the above ' stems with bundles of vascular tissue . You examine plant cells under a microscope arranged in a ring and notice many green round bodies within the leaves with parallel veins cells . The green structures are most likely . Which of the following statements is true about Involved and A directing the cells A Both and an ios photosynthesis . gy pe , produce . and produce , while making ' angiosperms produce cones . Which statement below best explains why Most have broad leaves , while mosses and can not grow tall ?

do not A They have no rootlike structures . Angiosperm seeds are enclosed within Taller plants in their surroundings release fruits . While gymnosperm seeds are not . chemicals that slow down their growth . They can not take in enough oxygen from their surroundings . They do not have true vascular tissue . BIG Idea . Describe three adaptations that plants have for living on land . Explain why each adaptation is important for a plant to survive on land . 10 403