chapter 5: biological diversity and conservation · chapter assessment, pp. 25-30 mindjogger...

Products Available FromNational Geographic SocietyTo order the following products,call National Geographic Societyat 1-800-368-2728:CD-ROMNGS PictureShow: Earth’sEndangered EnvironmentsVideodiscsGTV: Planetary ManagerGTV: Biodiversity

Index to NationalGeographic MagazineThe following articles may beused for research relating to thischapter:“Making Sense of theMillennium,” by Joel L.Swerdlow, January 1998.“Sanctuary: U. S. NationalWildlife Refuges,” by Douglas H.Chadwick, October 1996.

Teacher’s Corner

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Biological Diversity andConservation

Biological Diversity andConservation

TransparenciesReproducible MastersSection

Vanishing Species

Conservation ofBiodiversity

Section 5.1

Section 5.2

Teacher Classroom Resources

Reinforcement and Study Guide, pp. 19-21Concept Mapping, p. 5Critical Thinking/Problem Solving, p. 5BioLab and MiniLab Worksheets, pp. 21-22Laboratory Manual, pp. 31-34Tech Prep Applications, pp. 5-6Content Mastery, pp. 21-22, 24

Reinforcement and Study Guide, p. 22BioLab and MiniLab Worksheets, p. 23Laboratory Manual, pp. 35-38Content Mastery, pp. 21, 23-24Tech Prep Applications, pp. 7-8 L2

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Section Focus Transparency 10Reteaching Skills Transparencies 7a, 7b, 7c

Section Focus Transparency 11

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Assessment Resources Additional ResourcesSpanish ResourcesEnglish/Spanish AudiocassettesCooperative Learning in the Science ClassroomLesson Plans/Block Scheduling

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Chapter Assessment, pp. 25-30MindJogger VideoquizzesPerformance Assessment in the Biology ClassroomAlternate Assessment in the Science ClassroomComputer Test BankBDOL Interactive CD-ROM, Chapter 5 quiz

Chapter 5 OrganizerChapter 5 Organizer

Activities/FeaturesObjectivesSection

Vanishing SpeciesNational Science EducationStandards UCP.1-3; A.1,A.2; C.4, C.5, C.6; E.1, E.2;F.1-6; G.1-3 (2 sessions, 1 block)

Conservation ofBiodiversityNational Science EducationStandards UCP.1-3; A.1,A.2; C.4, C.5, C.6; E.1, E.2;F.2-6; G.1-3 (3 sessions, 1 block)

1. Explain biodiversity and its importance.2. Relate various threats to the loss of

biodiversity.

3. Describe strategies used in conservationbiology.

4. Relate success in protecting an endan-gered species to the methods used toprotect it.

MiniLab 5-1: Measuring Species Diversity, p. 116Problem-Solving Lab 5-1, p. 119Internet BioLab: Researching Informationon Exotic Pets, p. 130

MiniLab 5-2: Conservation of Soil, p. 126Art Connection: Wildlife Photography ofArt Wolfe, p. 132

Section 5.2

Section 5.1

MATERIALS LIST

BioLabp. 130 Internet access, paper, pencil

MiniLabsp. 116 paper, pencil, calculator(optional)p. 126 beaker, plastic tray, graduatedcylinder, water, lawn soil, lawn soil withgrass

Alternative Labp. 122 self-sealing plastic bags (2),paper towels, small cups (2), labels,water, vinegar, small seeds (40)

Quick Demosp. 121 cardboard, scissors, masking tapep. 122 test tube (2), one-hole stopper,glass tube, distilled water, Alka-Seltzertablet, pH paperp. 129 Ginko biloba leaves

Need Materials? Contact Carolina Biological Supply Company at 1-800-334-5551or at http://www.carolina.com

114A

Refer to pages 4T-5T of the Teacher Guide for an explanation of the National Science Education Standards correlations.

Key to Teaching StrategiesKey to Teaching Strategies

Level 1 activities should be appropriatefor students with learning difficulties.Level 2 activities should be within theability range of all students.Level 3 activities are designed for above-average students.ELL activities should be within the abilityrange of English Language Learners.

Cooperative Learning activitiesare designed for small group work.These strategies represent student prod-ucts that can be placed into a best-workportfolio.These strategies are useful in a blockscheduling format.

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The following multimedia resources are available from Glencoe.

Biology: The Dynamics of LifeCD-ROM

BioQuest: Biodiversity Park

The Infinite VoyageLife in the BalanceCrisis in the AtmosphereSecrets From a Frozen World

The Secret of Life SeriesGone Before You Know It: The Biodiversity Crisis

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http://www.carolina.com

Section

Biological DiversityA rain forest has a greater amount

of biological diversity, or biodiversity,than a cornfield. Biodiversity refersto the variety of life in an area. Thisarea could be Mississippi, Mexico, theSonoran Desert, or the entire planetEarth. The simplest and most com-mon measure of biodiversity is thenumber of species that live in a certainarea. For example, one acre of farm-land may be dominated by only onespecies of plant; one acre of rain forestmay contain 400 species of plants.The cornfield may contain twospecies of beetle, and the rain forestmay have 5000 species of beetles.

Where is biodiversity found?Areas around the world differ in

biodiversity. A hectare of tropicalrain forest in Amazonian Peru mayhave 300 tree species. Yet, onehectare of forest in the United Statesis more likely to have 30 tree speciesor less. Consider the number ofspecies of mammals; Canada has 163species, the United States has 367,and Mexico has 439. These examplesillustrate that terrestrial biodiversitytends to increase as you movetowards the equator. In fact, tropicalregions contain two-thirds of all landspecies on Earth. The richest envi-ronments for biodiversity are allwarm places: tropical rain forests,

5.1 VANISHING SPECIES 115

Imagine yourself standing in acornfield and then standing in arain forest. On this farmland in

Iowa, one species dominates—corn.However, in this temperate rain for-est in Washington State, you can seeand hear hundreds of different species.The rain forest is a richer ecosystem;it is home to more species of organ-isms. The rain forest is morelikely to survive disease,insects, and drought thanthe corn on the farmland.

SECTION PREVIEW

ObjectivesExplain biodiversityand its importance.Relate various threatsto the loss of biodiver-sity

Vocabularybiodiversityextinctionthreatened speciesendangered specieshabitat fragmentationedge effecthabitat degradationacid precipitationozone layerexotic species

5.1 Vanishing Species

A temperate rain forestin Washington (above)and a cornfield in Iowa(inset)

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Section 5.1

BIOLOGY: The Dynamics of Life SECTION FOCUS TRANSPARENCIES

Use with Chapter 5,Section 5.1

Why are animals kept in zoos?

What are some problems of keeping animals in zoos?

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Transparency Protecting Wildlife10 SECTION FOCUS

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From the World Book Encyclopedia.© 1999 World Book, Inc. By permission of the publisher.

PrepareKey ConceptsStudents will explore the conceptof biodiversity and factors thataffect it. They will learn abouthuman-created threats to biodi-versity.

Planning■ Gather cardboard and tape for

the first Quick Demo.■ Gather materials for the sec-

ond Quick Demo.■ Purchase or gather plastic

bags, paper towels, small cups,vinegar, and seeds for theAlternative Lab.

1 FocusBellringer Before presenting the lesson, display Section Focus Trans-parency 10 on the overhead pro-jector and have the studentsanswer the accompanying ques-tions.

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Biological Diversity and Conservation

What You’ll Learn■ You will explain the impor-

tance of biological diversity.■ You will distinguish environ-

mental changes that mayresult in the loss of species.

■ You will describe the work ofconservation biologists.

Why It’s ImportantWhen all the members of aspecies die, that species’ placein the ecosystem is gone for-ever. Knowledge of biologicaldiversity leads to strategies toprotect the permanent loss ofspecies from Earth.

Neighborhood NatureConsider the different animalsthat live in your area. Besideshumans, what are the mostcommon species in your neigh-borhood?

To find outmore about

biological diversity and conser-vation biology, visit the GlencoeScience Web Site.www.glencoe.com/sec/science

5

GETTING STARTEDGETTING STARTED

ChapterChapter

Earth may lose all of its giantpandas (above). Their loss ofhabitat, due to the encroach-ment of humans, has put themin peril. The passenger pigeon(inset), once so common it filledthe skies of North America, washunted to extinction.

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Theme DevelopmentHomeostasis is a major theme ofthis chapter, which correlatesincreases in human populationswith threats to biodiversity.Methods of reducing these threatsare presented.

Chapter 5Chapter 5

MultipleLearningStyles

Look for the following logos for strategies that emphasize different learning modalities.

Visual-Spatial Portfolio, pp. 118,120, 121; Project, p. 119; Meeting

Individual Needs, p. 126; Extension, p. 129

Interpersonal Biology Journal, p. 118; Meeting Individual Needs,

p. 128Linguistic Tying to Previous Know-ledge, p. 118; Enrichment, p. 123;

Extension, p. 124; Portfolio, p. 126;Biology Journal, p. 127

Logical-MathematicalMeeting Individual Needs,

p. 116; Project, p. 117; Quick Demo,p. 121; Reinforcement, p. 123

GETTING STARTED DEMOGETTING STARTED DEMO

Hold up a picture of a scene innature. Ask students to iden-tify common organisms. Havethem identify organisms thatare few in number and thenestimate the number of speciesin the photograph. Explainthat this unit is about species,including how many specieslive in different areas of ourplanet and how we can protectspecies from extinction.

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If time does not permit teach-ing the entire chapter, use theBioDigest at the end of theunit as an overview.

Assessment PlannerAssessment PlannerPortfolio Assessment

Portfolio, TWE, pp. 118, 120, 121, 126Problem-Solving Lab, TWE, p. 119Assessment, TWE, pp. 124, 127, 129

Performance AssessmentMiniLab, SE, pp. 116, 126Assessment, TWE, p. 123Alternative Lab, TWE, pp. 122-123Problem-Solving Lab, TWE, p. 128

BioLab, SE, pp. 130-131BioLab, TWE, pp. 130-131

Knowledge AssessmentMiniLab, TWE, pp. 116, 126Assessment, TWE, p. 121Section Assessment, SE, pp. 124, 129Chapter Assessment, SE, pp. 133-135

Skill AssessmentAlternative Lab, TWE, pp. 122-123

Resource ManagerResource Manager

Section Focus Transparency 10and Master

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http://www.glencoe.com/sec/science

more nutrient-rich soil. However, ifeverything else is the same, the largerthe island the greater the biodiversityit contains. These findings fromisland research have become impor-tant for managing and designingnational parks and protected areas.Such areas have become “islands,”not surrounded by oceans, but sur-rounded by human populations withbuildings and roads.

Importance ofBiodiversity

Compare a parking lot havingnothing but asphalt to your favoriteplace in nature, perhaps a meadow, aforest, or a thriving lake. Which envi-ronment do you think is more pleas-ant? The presence of different formsof life makes our planet beautiful. Youmay go to the natural area to relax orto think. Artists get inspiration fromthese areas for songs, paintings, andliterature. Looking at the beauty ofone of Art Wolfe’s photograph in theArt Connection can help you appreci-ate the beauty biodiversity gives ourworld. Beyond beauty, why is biodi-versity important?

Importance to natureOrganisms are adapted to live

together in communities. Althoughecologists know of many complexrelationships among organisms, manyrelationships are yet to be discovered.Scientists do know that if a species islost from an ecosystem, the loss mayhave consequences for other livingthings. Other organisms suffer whenan organism they feed upon isremoved permanently from a foodchain or food web. A population maysoon exceed the area’s carrying capac-ity if its predators are removed. If thesymbiotic relationships among organ-isms are broken due to the loss of oneof the dependent species, then theother species will soon be affected.

Life depends on life. Animalscould not exist without green plants,many flowering plants could not existwithout animals to pollinate them,and plants need decomposers tobreak dead or decaying material intonutrients they can use. A rain foresttree grows from nutrients in the soilreleased by decomposers. A sloth eatsthe leaves of this tree. Moss grows onthe back of the sloth. Living thingscreate niches for other living things.


Figure 5.2Although Iceland(left) is a biggerisland than Maui(right), Maui has agreater biodiversitydue to its warm cli-mate and good soils.Nevertheless, allother things beingequal, the larger theisland the greater itsbiodiversity.

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ReinforcementAsk students to recall the biomesthey studied in Chapter 3. Whichhad the highest biological diversi-ty? tropical rain forest

Chalkboard ActivityWrite the terms number of speciesand number of organisms on theboard. Ask students to explain thedifference. Which is a better indi-cator of biological diversity? num-ber of species

EnrichmentTo establish how biodiversityhelps meet our needs, have stu-dents list 20 things people usethat come from 20 differentplants or animals. L2

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Measuring Species DiversityIndex of diversity (I.D.) is a mathe-matical way of expressing the amount of biodiversity and species distribution in a community. Communities with many different species (a high index of diversity) will be able to withstand environ-mental changes better than communities with only a few species (a low index of diversity).

Procedure ! Copy the data table below.@ Walk a city block or an area designated by your teacher

and record the number of different species of trees pre-sent (you don’t have to know their names, just that theydiffer by species). Record this number in your data table.

# Walk the block or area again. This time, make a list of thetrees by assigning each a number as you walk by it. Placean X under Tree 1 on your list. If Tree 2 is the same speciesas Tree 1, mark an X below it. Continue to mark an Xunder the trees as long as the species is the same as theprevious one. When a different species is observed, markan O under that tree on your list. Continue to mark an Oif the next tree is the same species as the previous. If thenext tree is different, mark an X.

$ Record in your data table: a. the number of “runs.” Runs are represented by a group

of similar symbols in a row. Example—XXXXOOXO wouldbe 4 runs (XXXX = 1 run, OO = 2 runs, X = 3, O = 4).

b. the total number of trees counted.% Calculate the Index of Diversity (I.D.) using the formula in

the data table.

Analysis1. Compare how your tree I.D. might compare with that of a

vacant lot and with that of a grass lawn. Explain youranswer.

2. If humans were concerned about biological diversity,would it be best to have a low or high I.D. for a particularenvironment? Explain your answer.

MiniLab 5-1MiniLab 5-1coral reefs, and large tropical lakes.Learn one way to measure species dis-tribution in the MiniLab on this page.

The study of islands has led toadditional understanding of factorsthat influence biodiversity. Largeislands tend to have a higher biodi-versity than smaller islands, as shownin Figure 5.1. These Caribbeanislands are near each other; however,they differ in the number of speciesthey each contain. For example,Redonda—a small island—has fewerspecies than Saba—a large island.Why do larger islands tend to have agreater biodiversity than smallerislands? The larger islands have morespace and are more likely to have agreater variety of environments andecosystems. In some cases, however,smaller islands can have a larger bio-diversity than larger islands.Compare the huge island of Icelandto the much smaller island of Maui inFigure 5.2. Maui has more biodiver-sity because it is warmer and has

116 BIOLOGICAL DIVERSITY AND CONSERVATION

A tree-lined street

Number of species =

Number of runs =

Number of trees =

Index of diversity =

Data Table

Number of species � number of runsNumber of trees

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Figure 5.1The relative number of species on anisland can be predicted from the size ofthe island. For example, Puerto Rico islarger than Montserrat, and it has morespecies.

Using Numbers

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2 Teach

Purpose Students will survey an area nearschool and calculate an index ofdiversity (I.D.).

Process Skillsapply concepts, collect data, com-pare and contrast, interpret data,observe and infer, organize data,predict, use numbers

Teaching Strategies■ Any plant type can be used.For example, the study could beconducted with flowering plantsor cacti. Simply have studentsfollow a marked path throughany community and record theirobservations.■ If possible, locate and mark offan area that contains about 10trees of different species. Thetrees do not have to be in astraight line but will have to bemarked so they can be numberedin order of observation.■ If you wish, draw a map of thearea to be visited and give copiesto students. Include a birds-eyediagram of the trees and pre-number them.■ If a field trip is not possible,provide students with a map oftrees labeled by species.

Expected ResultsNumbers below one (decimals)indicate a low index of diversity.Numbers over 1 show greaterdiversity. A typical city street mayyield an I.D. of slightly over 1.

Analysis1. A vacant lot might have a

higher I.D. because many dif-ferent species might be pre-sent in a small area. A grasslawn would have a muchlower I.D., perhaps with onlyone species present.

2. A higher I.D. would indicategreater species diversity.Communities with a low I.D.may be prone to speciesextinction if environmentalconditions change.

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MiniLab 5-1MiniLab 5-1

MEETING INDIVIDUAL NEEDS MEETING INDIVIDUAL NEEDS

Learning DisabledLogical-Mathematical The simplestway of calculating biodiversity is to

count the number of species in an area.Have students count the number ofspecies in a fish tank to understand thisconcept. Caution them to count the num-ber of species, not the number of fish.P

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Cultural Diversity

George Washington CarverGeorge Washington Carver (1865–1943) isbest known for establishing crops such ascotton, peanuts, and sweet potatoes inthe southern United States. He showedhow reliance on one crop depletes thesoil of nutrients. Have students researchfarming methods in different cultures andmake models of them.

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P R O J E C TComparing Diversity

Logical-Mathematical Have stu-dents rope off two different areas

of the school grounds, each about 1 yard(1 m) square. Ask them to count all thespecies of plants or insects in or aboveeach area. Then have them compare thenumbers and suggest reasons for any dif-ferences in diversity.

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Knowledge Ask students why a citywith one major industry may suffer if there isa downturn in that industry, whereas a citywith a diverse industrial base will be betterable to withstand an economic downturn.Use the Performance Task Assessment Listfor Making Observations and Inferences inPASC, p. 17. L2

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AssessmentAssessment

CD-ROMBiology: The Dynamicsof Life

BioQuest: Biodiversity ParkDisc 3, 4

VIDEOTAPEThe Secret of Life

Gone Before You Know It: The Biodiversity Crisis


BioLab and MiniLab Work-sheets, p. 21 L2

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Does species extinction correlate with land area?Species are at risk of extinction when their habitats aredestroyed through human action. Is there a better chance forsurvival when the land area is large?

AnalysisA study of land mammals was conducted by a scientist to

determine the effect of land area on species extinction. Hisresearch was confined to a group of South Pacific islands ofIndonesia. The scientist’s basis for determining the initialnumber of species present was based on research conductedby earlier scientists and from fossil evidence.

Thinking Critically1. In general, how does land area correlate with loss of

species?2. What is the relationship between island size and the ini-

tial number of species?3. Hypothesize why the study was conducted on only land

mammals.

Problem-Solving Lab 5-1Problem-Solving Lab 5-1 Interpreting DataLoss of Biodiversity

Have you ever seen a flock of pas-senger pigeons? How about a wood-land caribou, relic leopard frog, orLouisiana prairie vole? Unless youhave seen a photograph or a stuffedmuseum specimen, your answer willbe no. These animals are extinct.Extinction (ek STINGK shun) is thedisappearance of a species when thelast of its members dies. Since 1980,almost 40 species of plants and ani-mals living in the United States havebecome extinct. Although extinctioncan occur as a result of naturalprocesses, humans have been responsi-ble for the extinction of many species.Is there a link between the land areaa species can inhabit and extinction?Find out in the Problem-Solving Lab.

When the population of a speciesbegins declining rapidly, the species issaid to be a threatened species.African elephants, for example, arelisted as a threatened species. In theearly 1970s, the wild elephant popula-tion numbered about three million.Twenty years later, it numbered onlyabout 700 000. Elephants have tradi-tionally been hunted for their ivorytusks, which are used to make jewelryand ornamental carvings. Many coun-tries have banned the importation andsale of ivory, and this has helped slow

IslandPercentof lossExtinctions

Initial numberof species

Area in km2

Borneo

Java

Bali

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39

47

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751 709

126 806

5 443

Table 5.1 Relationship of land area to extinctions

Figure 5.4Several animalspecies in theUnited Statesare threatened.

the decline of the elephant popula-tion. Figure 5.4 shows some threat-ened animal species under protectionin the United States.

Sea otters(Enhydra lutrissubspecies nereis)have been huntedfor centuries fortheir fur.

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Wildlife experts classify logger-head turtles (Caretta caretta),as well as five other sea turtlespecies, as threatened.

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Purpose Students will determine thatreduced land area contributes tothe extinction of species.

Process Skillsthink critically, analyze informa-tion, compare and contrast, drawa conclusion, interpret data, pre-dict, recognize cause and effect,use numbers

Teaching Strategies■ You may wish to ask studentsto locate these island areas on amap.■ Review the procedure for cal-culating percent. Allow studentsto use calculators.

Thinking Critically

1. There is a higher percent ofspecies loss for smaller areas.

2. The larger the island, themore initial species it has.

3. Answers will vary, but stu-dents may mention that it’seasier to trap and observeland mammals, and the initialdata on species numbers maybe more reliable.

Portfolio Have studentswrite a newspaper article describ-ing some possible ways to reducethe number of extinctions of landmammal species on a small islandsuch as Bali. Use the PerformanceTask Assessment List for News-paper Article in PASC, p. 69.

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Problem-Solving Lab 5-1Problem-Solving Lab 5-1

Biodiversity also brings stability toan ecosystem. A pest could destroyall the corn in a farmer’s field, but itwould be far more difficult for aninsect or disease to destroy all indi-viduals of a plant species in a rainforest. These plants would exist inmany parts of the rain forest, makingit more difficult for the insect or dis-ease to spread. Although ecosystemsare stronger due to their biodiversity,losing species may weaken them.One hypothesis suggests species in anecosystem are similar to rivets hold-ing an airplane together. A few rivetsmight break, and nothing will hap-pen, but at some point enough rivetsbreak and the airplane falls apart.

Importance to peopleHumans depend on other organ-

isms for their needs. Oxygen is sup-plied and carbon dioxide is removedfrom the air by diverse species ofplants and algae living in a variety ofecosystems. Biodiversity gives peoplea diverse diet. Beef, chicken, tuna,shrimp, and pork are only a few ofthe meats and fish we eat. Think of

all the plant products that people eat,from almonds to zucchini. When youconsider all the foods eaten by all thepeople in the world, you realize thathundreds of species help nourish thehuman population. Biodiversity canhelp breeders make food crops growbetter. For example, through cross-breeding with a wild plant, a foodcrop can be made pest-resistant ordrought-tolerant. People also rely onthe living world for materials used inclothes, furniture, and buildings.

Biodiversity can also be used toimprove people’s health. Living thingssupply the world pharmacy. Althoughdrug companies may manufacturesynthetic drugs, active compoundsare usually first isolated from livingthings, such as shown in Figure 5.3.The antibiotic penicillin came fromthe mold, Penicillium; the antimalarialdrug quinine came from the bark ofthe cinchona tree. Preserving biodi-versity ensures there will be a largesupply of living things, some of whichmay provide future drugs. Maybe acure for cancer or HIV is contained inthe leaves of a small rain forest plant.


Figure 5.3Diverse living things providemany important medical drugs.

OriginWORDWORD

Extinction From the Latinwords ex, meaning“out,” and stinguere,meaning “toquench.” A speciesbecomes extinctwhen its last organisms die.

Willow bark was the originalsource of aspirin.

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Taxol, a strong anti-cancer drug, wasfirst discovered inthe Pacific yew.

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Rosy periwinkle is the sourceof drugs for Hodgkin’s diseaseand leukemia.

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Concept DevelopmentAsk students to explain how therelationship between organismsand ecosystems is similar to therelationship between people andcities.

Tying to PreviousKnowledge

Linguistic Have studentsdescribe ways that organ-

isms depend upon other organ-isms. food, symbiotic relationships,nutrient cycling

Revealing MisconceptionsStudents may not realize thatmany drugs begin as substancesthat have been isolated from liv-ing things. Point this out usingFigure 5.3.

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PortfolioPortfolio

Diagramming DependenceVisual-Spatial Ask students to drawa realistic food web in which the

removal of one organism could adverselyaffect at least five other organisms.P

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BIOLOGY JOURNAL BIOLOGY JOURNAL

An Alphabet of BiodiversityInterpersonal Have students workin groups to create an alphabet of

biodiversity. For letters A through Z, theywill write one organism that people useand then describe its use, such as for food,shelter, or clothing. For example: Apple—food.

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P R O J E C TFinding Answers

Visual-Spatial Have studentschoose an extinct organism and

research possible reasons for its extinc-tion. Create a classroom bulletin board onextinction.

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VIDEODISCSTV: BiodiversityImportance of Diversity

Unit 1, Side 1, 2 min. 5 sec.

!7lj.18."


Concept Mapping, p. 5

Tech Prep Applications, p. 5L2

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becoming virtual islands. Habitatfragmentation is the separation ofwilderness areas from other wilder-ness areas. Habitat fragmentationpresents problems for many organ-isms. Recall how the study of islandsrevealed that the smaller the island,the fewer species it supports.Fragmented areas are like islands,and the smaller the fragment, the lessbiodiversity it will support.

Biotic issuesHabitat fragmentation, as shown

in Figure 5.7, presents problems fororganisms that need large areas togather food. Large predators cannotobtain enough food if they arerestricted to a small area. Someorganisms, such as zebra and wilde-beest, migrate with the seasons toensure a constant grass supply. Iftheir range is restricted, they willstarve. Habitat fragmentation alsomakes it difficult for species to re-establish themselves in an area.Imagine a small fragment of forestwhere a species of salamander lives. Afast burning fire destroys the treesand all the salamanders. In nonfrag-mented land, when new trees grow,new salamanders would eventuallymove back into the land. However, in

the fragmented land, there is nomigratory route for the salamandersto reestablish their population.

Abiotic issuesAnother problem with habitat

fragmentation is that it can changethe climate of the area. Consider atropical rain forest. Recall that thearea under the canopy is moist andshady. Now suppose loggers come inand cut everything down, except for aplot of land equal in size to a footballfield. The once shady, moist area isnow exposed from the sides to sun-light and winds. The area dries out,and organisms that evolved in rain


Figure 5.6 Coral reefs are rich inbiodiversity. Removalof coral results in aloss of habitat forreef organisms.

Figure 5.7Wildlife areas thatbecome surroundedby human develop-ment result in habitatfragmentation.

EnrichmentHave students find out how stripmining for coal differs from themore traditional deep-tunnelmining. Also ask them toresearch how companies attemptto restore mined land to a usablenatural setting.

Knowledge Ask studentsto explain which type of organ-isms tend to be most affected byhabitat fragmentation. largepredators and organisms thatmigrate L2

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A species is considered to be anendangered species when its num-bers become so low that extinction ispossible. In Africa, the black rhinoc-eros has become an endangeredspecies. Poachers hunt and kill theseanimals for their horns. Rhinoceroshorns are composed of fused hairrather than bone or ivory. In theMiddle East, the horns are carvedinto handles for ceremonial daggers.In parts of Asia, some people believepowdered horn is an herbal medicine.Figure 5.5 shows just two endan-gered species in the United States.Unfortunately, there are many more.

Threats to BiodiversityComplex interactions among

species make ecosystems unique andspecies are usually well adapted totheir habitats. Changes to habitats canthreaten organisms with extinction. Aspopulations of people increase, theimpact from their growth and devel-opment is altering the face of Earthand pushing many other species to thebrink of extinction.

Habitat lossThe biggest threat to biodiversity is

habitat loss. When a rain forest is madeinto a cattle pasture, a meadow madeinto a mall parking lot, or a swampdrained for housing, habitats are lost.With their habitats gone, the essentialsof life are lost for species dependentupon these habitats, and species disap-pear. In tropical rain forests, the Earth’srichest source of biodiversity, an areathe size of Florida is cut or burnedevery year. Coral reefs, such as shownin Figure 5.6, are also very rich inbiodiversity. Water and temperaturechanges can damage coral reefs. Peopleremove large sections of coral reef for avariety of reasons. In some areas, coralis mined for building materials. Coralreef is often collected for souvenirsand aquarium decorations. Throughhabitat loss, as well as pollution anddisease, many species that live in coralreefs are in danger of extinction.

Habitat fragmentationAs roads cut across wilderness

areas, and as building projects expandinto new areas, many habitats are


Figure 5.5In the United States,scientists have developed programsdesigned to saveendangered species.

Florida manatees (Trichechus manatus),sometimes called "sea cows," are endan-gered due to loss of habitat and injuryfrom barges and motorboats.

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Urban growth hasdestroyed much of theCalifornia condor’s habi-tat. To protect the species,the few remainingCalifornia condors(Gymnogyps californi-anus) were captured andplaced in reserves.

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Revealing MisconceptionsWhile biologists suspect thathumans have increased the rate ofnatural extinctions, help studentsrealize that extinction is a naturalprocess. Dinosaurs were extinctbefore people evolved. Extinctionand evolution often go hand-in-hand.

Concept DevelopmentAsk students to explain ways thatpeople alter habitats. Try to iden-tify whether the changes affectthe biotic or abiotic factors of thathabitat. For example, cuttingtrees can have biotic affects suchas reducing the food supply forcertain animals. It can also haveabiotic effects, such as increasingthe amount of sunlight thatreaches an area.

PortfolioPortfolio

Observing Habitat DestructionVisual-Spatial Have students recordany direct evidence they observe of

habitat destruction brought on byhumans. Ask them to describe how theconditions they observe might be con-tributing to the reduction in numbers ofsome native plant or animal species.P

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Quick DemoQuick Demo

Logical-MathematicalCut out a cardboard

square to represent a nationalpark. Put strips of maskingtape along each edge to repre-sent edge effect. Now cut thecardboard in half and tell stu-dents that a road has justdivided the park. For each halfof the park, put masking tapeon the newly created edge.Ask students to explain whyroads create more edgeeffects.

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PortfolioPortfolio

Measuring Solid WasteGeneration

Visual-Spatial Have students pre-pare a table to illustrate the solid

waste generated by their families per day,week, month, year, and decade. Use 1.8kg of waste per person per day. Week =12.6 kg; month = 54 kg; year = 657 kg;decade = 6570 kg.

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VIDEODISCGTV: PlanetaryManager

Side 1: Vanishing Act

STV: BiodiversityLoss of DiversityUnit 1, Side 1, 6 min. 20 sec.

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VIDEODISCGTV: Planetary ManagerSide 2: Shall We Gather at the River?

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VIDEODISCThe Infinite VoyageLife in the Balance

Rondonia: Home of a Dying RainForest (Ch. 3) 4 min.

Southern California’s Chaparral:Extinction by Development (Ch. 6) 9 min.

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!7_jJ"The Infinite Voyage Crisis in theAtmosphere: Chlorofluorocar-bons and Their Effect on theOzone Layer (Ch. 5) 4 min.

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one shown in Figure 5.9. As thealgae die, they sink and decay,removing needed oxygen from thewater. Silt from eroded soils can also enter water and clog the gills offishes. In coral reefs, silt can coverthe coral and prevent sufficient lightfrom reaching the photosyntheticorganisms within the coral polyps.Detergents, heavy metals, and indus-trial chemicals in runoff can causesickness and death in aquatic organ-isms. Abandoned drift nets in oceanscan entangle and kill dolphins,whales, and other sea life.

Land pollutionHow much garbage does your

family produce every day? Trash, orsolid waste, is made up of the cans,bottles, paper, plastic, metals, dirt,and spoiled food that people throwaway every day. The averageAmerican produces about 1.8 kg ofsolid waste daily. That’s a total of

about 657 kg of waste per person peryear. Does it ever decompose?Although some of it might, most ofour trash becomes part of the billionsof tons of solid waste that are buriedin landfills all over the world. As youmight expect, these landfills destroywildlife habitats by taking up spaceand polluting the immediate area.

The use of pesticides and otherchemicals can also lead to habitatdegradation. For many years, DDTwas commonly sprayed on crops tocontrol insects and sprayed on waterto kill mosquito larvae. Birds that fedon insects, fish, and other small ani-mals exposed to DDT were observedto have high levels of DDT in theirbodies. The DDT was passed on tothe predators that ate these birds.Because of the DDT in their bodies,some species of predators, such as theAmerican bald eagle and the pere-grine falcon, tended to lay eggs withvery thin shells that cracked easily,

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Figure 5.9Cattle manure con-tains nitrogen andother nutrients thatmake it valuable as aplant fertilizer. Buttoo much of a goodthing can cause pollu-tion problems.

The cattle on this feedlot produce morewaste than the decom-posers in the soil canhandle. If the waste isnot contained, it canbe washed into nearbystreams by rainfall.

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The large amounts of nitro-gen in runoff from a feed lotstimulate the rapid growth ofalgae in waterways down-stream. This lush growth ofalgae consumes all or most ofthe oxygen in the water,making it impossible forinsects, fishes, and other ani-mals to survive.

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ReinforcementLogical-Mathematical Havestudents prepare a circle

graph showing the percentage byweight of urban solid waste.Provide these data: paper/card-board 41%; yard waste 18%;food waste 9%; metal 9%; glass8%; plastic 7%; wood 3%; rub-ber/leather 3%; cloth 1%; andother 1%.

EnrichmentLinguistic Rachel Carson’sbook Silent Spring was

important in creating awarenessof problems resulting from theuse of DDT. Have students readall or part of this book and/orresearch Carson’s life.

Performance Assessmentin the Biology Classroom, p. 55,Finding Out Why a Pond Is Dying.Have students carry out this act-ivity to determine how pollutantsaffect pond ecosystems.

3 AssessCheck for UnderstandingAsk students to explain how thefollowing could lead to a loss ofspecies.

a. habitat lossb. habitat fragmentationc. acid raind. introduction of exotics

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and the word vinegar.5. Prepare a data table to record your

observations. Record the number ofseeds that germinate during the nextfour days. Germinating seeds show aroot growing from the seed.

Expected ResultsSeeds soaked in water will germinate, butmost of those soaked in vinegar will not.

Analysis1. Compare the number of germinated

seeds after four days. How do thewater-soaked and vinegar-soakedseeds compare? There is less germina-tion of the vinegar-soaked seeds.

2. Vinegar is an acid. Explain how acidprecipitation might affect seed germi-nation. Acid precipitation could delayor prevent seed germination.

Skill Design an experiment thatdetermines the tolerance limit for mus-tard seed germination in vinegar.Conduct the experiment if time permits.Use the Performance Task AssessmentList for Designing an Experiment inPASC, p. 23. L2

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forest conditions can no longer sur-vive at the edges. The different con-ditions along the boundaries of anecosystem are called an edge effect.

Habitat degradationAnother threat to biodiversity is

habitat degradation, the damage toa habitat by pollution. Three types ofpollution are air, water, and land pol-lution. Air pollution can have nega-tive effects on living organisms, suchas causing breathing problems andirritating membranes in the eyes andnose. Although pollutants can enterthe atmosphere in many ways—including volcanic eruptions and for-est fires—the burning of fossil fuels isthe greatest source of air pollution.

Acid precipitation—rain, snow,sleet, and fog with low pH values—isresponsible for the deterioration offorests and lakes. Sulfur dioxide fromcoal-burning factories and nitrogenoxides from automobile exhaustscombine with water vapor in the airto form acidic droplets of watervapor. When the acidic droplets of

water fall from the sky as precipita-tion, the moisture leaches calcium,potassium, and other valuable nutri-ents from the soil. This loss of nutri-ents can lead to the death of trees.Acid precipitation also damages planttissues and interferes with plantgrowth. Many trees in the forests ofthe United States are dying becauseof acid rain and fog, as shown inFigure 5.8. Acid precipitation alsohas severe effects on lake ecosystems.Acid precipitation falling into a lake,or entering it as runoff from streams,causes the pH of the lake water to fallbelow normal. The excess acidity cancause the death of plants, animals,and other organisms.

The atmosphere contains a sort ofsunscreen—known as the ozonelayer—that helps to protect livingorganisms on Earth’s surface fromreceiving damaging or lethal doses ofultraviolet radiation. The chemicalformula for ozone is O3, meaning itcontains three oxygen atoms.Chlorofluorocarbons, or CFCs, aresynthetic chemicals that break downthe ozone layer. CFCs are used ascoolants in refrigerators and air condi-tioners, and in the production of poly-styrene. Some scientists have hypoth-esized that the loss of the ozone layer,and the resulting increased ultravioletradiation, may partially explain whymore frogs and toads are born withdeformities, and why many amphibianpopulations are declining.

Water pollutionWater pollution degrades aquatic

habitats in streams, rivers, lakes, andoceans. A variety of pollutants canaffect aquatic life. Excess fertilizersand animal wastes from farms areoften carried by rain into streams andlakes. The sudden availability ofnutrients causes algal blooms, theexcessive growth of algae, such as the


Figure 5.8Acid precipitationand acid fog arebelieved to be majorcontributors of thisdamage to trees inMount Mitchell,North Carolina.

Revealing MisconceptionsStudents may think that tap waterhas a pH of 7, but tap water isusually slightly acidic. Illustratethis point by using pH paper totest the tap water in your area.Explain that the pH of tap watercan be affected by chlorine orother additives used in waterpurification and by contaminantsin the pipes.

Alternative LabAcids and Seed Germination

Purpose Students will observe the effect of acid pre-cipitation on seed germination.

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Materials self-sealing plastic bags, paper toweling,small cups, labels, water, vinegar, small seedsProcedureGive the following directions to students.

1. Place 20 seeds in a small, labeled cup ofwater and 20 seeds in a small, labeledcup of vinegar. CAUTION: Wear goggleswhile handling and pouring vinegar.Wash your hands after working withseeds.

2. Allow the seeds to remain in the liq-uids overnight.

3. The next day, remove seeds from thewater. Wrap the seeds in a papertowel. Moisten the towel with waterand slide it into a self-sealing plasticbag. Label the bag with your name,date, and the word water.

4. Repeat step 3 for the seeds in vinegar.Moisten the towel with vinegar andlabel the bag with your name, date,122


Determine the pH of a testtube of distilled water usingpH paper. Add an Alka-Seltzertablet to the water. Place astopper that has a plastic tubeextending into the test tube.Allow the gas generated in thetube (carbon dioxide) to bub-ble through another tube ofdistilled water. Check the pH ofthe tube that received the gas.Explain that this shows waterand carbon dioxide joining toform carbonic acid.

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Laboratory Manual, pp. 31-38

Critical Thinking/ProblemSolving, p. 5

Reteaching Skills Transpar-encies 7a-7c and Masters

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killing the chicks inside. The popula-tions of these species showed sharpdeclines. These observations led tothe banning of DDT, and helpedmore people become aware of con-servation biology issues.

Introduction of exoticsPeople, either on purpose or by

accident, sometimes introduce a newspecies into an ecosystem. This cancause problems for the native species.When people brought goats to SantaCatalina Island, located off the coastof California, 48 native species ofplants soon disappeared from the localenvironment. Building the Erie canalin the nineteenth century made it pos-sible for the sea lamprey to swim into

the Great Lakes. The sea lampreyresembles an eel, with a round clampfor a mouth. It swims up to a fish,clamps onto its body, and sucks thefluids out of the fish using its sharpteeth and tongue. The lamprey hastotally eliminated certain fish speciesfrom some lakes. Exotic species, suchas the goat and the lamprey, areorganisms that are not native to a par-ticular area. Other examples of exoticspecies are shown in Figure 5.10.When exotic species are introducedinto an area, these species can grow atan exponential rate due to a lack ofcompetitors and a lack of predators.They may take over niches of nativespecies, and can eventually replace thenative species completely.

Section AssessmentSection Assessment

Understanding Main Ideas1. What are two causes for a species to become

threatened or endangered?2. How does acid precipitation kill trees?3. What is an edge effect?4. How do exotic species affect populations of

native species?

Thinking Critically5. Suggest reasons why warm tropical areas have

more biodiversity than cooler areas.

6. Designing an Experiment Thinning of theozone layer allows increased ultraviolet radiationfrom the sun to penetrate Earth’s atmosphere.Your hypothesis is that increased ultraviolet radi-ation results in higher mortality rates for frogs.Design an experiment to test your hypothesis.Remember to set up a control group. For morehelp, refer to Practicing Scientific Methods in theSkill Handbook.

SKILL REVIEWSKILL REVIEW

Figure 5.10Exotic speciescan cause manyproblems whenintroduced intonew ecosystems.


Zebra mussels were intro-duced into the Great Lakesfrom the ballast of ships.These fast-growing musselsfilter food from the water,blocking many food chains.

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Kudzu was introduced into theU.S. from Russia and Japan as anornamental and to reduce soilerosion. It grows and reproducesrapidly, smothering areas ofnative plants.

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ReteachHave students explain the rela-tionship between the words ineach of the following pairs.

a. island size—biodiversityb. threatened species—endan-

gered speciesc. exotic species—native speciesd. algae blooms—fertilizers

ExtensionLinguistic The introductionof exotic species can also

cause problems for people. Askstudents to research the introduc-tion of an exotic species and pre-pare a five-minute presentationto share what they learn.

Portfolio Have studentsprovide a written definition ofbiodiversity and reasons why weshould protect it.

4 CloseActivityHave students name conditions or practices that increase prob-lems associated with pollutionand endangered species.

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Section AssessmentSection AssessmentSection Assessment1. Answers may include habitat loss,

degradation, or fragmentation; intro-duction of exotic species; or excessivehunting or collecting.

2. by destroying their leaves or needlesthrough acid fog and precipitation orby changing the soil pH, which causesleaching of nutrients

3. different conditions along the bound-aries of a natural area

4. The exotics can out-compete the nativespecies for food or shelter. Or theexotic species may eat a native species.

5. Possible reasons: They have longergrowing seasons, greater biomass, anda longer time since their last ice age.

6. The control and experimental groupsof frogs should both include adequatenumbers. The experimental group willbe exposed to a greater amount ofultraviolet radiation. Mortality rates ofthe groups will be compared.

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Content Mastery, p. 22Reinforcement and Study

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Section

5.2 CONSERVATION OF BIODIVERSITY 125

Strategies ofConservation Biology

Conservation biology is a newfield that studies methods and imple-ments plans to protect biodiversity.Effective conservation strategies arebased on principles of ecology. Thesestrategies include natural resourceconservation and species conserva-tion. Learn about soil conservation inthe MiniLab on the next page.

Many species are in danger due tothe actions of humans, so workingwith people is an important part ofconservation biology. Conservationbiologists not only focus on ecology,but also seek to understand law, poli-tics, sociology, and economics to findeffective strategies for conservingEarth’s biodiversity.

Legal protections of species In response to concern about

extinction, President Nixon signedthe U.S. Endangered Species Act intolaw in 1973. This law made it illegalto harm any species on the endan-gered or threatened species lists.Further, the law made it illegal forfederal agencies to fund any projectthat would harm organisms on theselists. Harm includes changing anecosystem where endangered orthreatened species live. This law hasbeen partially responsible for recover-ies in the populations of the Americanbald eagle, the American alligator,and the brown pelican. Other coun-tries have enacted similar laws.International agreements also protectendangered or threatened species.For example, the Convention on

The loss of species from Earth is apermanent tragedy. Fortunately,people are working to protect

species from extinction. One strategy is tobring organisms back into areas wherethey once lived, as is being done inYellowstone National Park withgray wolves. Organisms areendangered for a variety ofreasons, and perhapsthrough a variety ofstrategies, these organ-isms can be protected.

5.2 Conservation ofBiodiversity

The graywolf

SECTION PREVIEW

ObjectivesDescribe strategiesused in conservationbiology.Relate success in pro-tecting an endangeredspecies to the methodsused to protect it.

Vocabularyconservation biologysustainable usehabitat corridorsreintroduction

programscaptivity

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Section 5.2

PrepareKey ConceptsStudents will learn how conserva-tion biology strategies are used toprevent the loss of species.Throughout the section, studentswill learn success stories in con-servation biology.

Planning■ Gather soil, trays, beakers, and

water for the MiniLab.■ Gather ginkgo leaves for the

Quick Demo.■ Arrange access to the Internet

for the BioLab.

1 FocusBellringer Before presenting the lesson, display Section Focus Trans-parency 11 on the overhead pro-jector and have the studentsanswer the accompanying ques-tions.

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BIOLOGY: The Dynamics of Life SECTION FOCUS TRANSPARENCIES

Use with Chapter 5,Section 5.2

How is the gardener’s activity helpful?

How might the activity be harmful?

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VIDEODISCSTV: BiodiversityPreserving Diversity (in its entirety)

Unit 2, Side 1, 12 min. 10 sec.

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Section Focus Transparency 11and Master

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to let people use the resources ofwilderness areas in ways that will notdamage the ecosystem. For example,in some tropical rain forests in theAmazon, people harvest Brazil nuts, asshown in Figure 5.12, to eat and tosell. This practice gives people theopportunity to earn a living, and ithelps them appreciate the value ofpreserving the area. When local peo-ple benefit from a natural area,through jobs or resources, they aremore likely to cooperate with thearea’s preservation. For this reason,the preferred choice of people hired toprotect natural areas are local people.

If a conservation group hadenough money to buy 1000 acres offorest to set aside for protection,what would be their best strategy?Should they buy one big 1000-acreplot or ten 100-acre plots? Recall theresearch concerning number ofspecies on islands of different sizes.In general, larger islands have morespecies than smaller islands.Therefore, to best protect the biodi-versity of an area, the conservationgroup should generally buy one largeplot of land. However, if the ten plotsprotected a variety of ecosystems,


Figure 5.12Allowing sustainable use of wildlife areasprovides additional motivation for localpeople to protect these areas. The sale ofBrazil nuts, sustainably harvested from rainforests in the Amazon, provides income forpeople living in and near rain forests.

Figure 5.11Yellowstone NationalPark was the firstnational park in theUnited States. It ishome to a wide vari-ety of life.

they may be a better choice for con-serving biodiversity. Each decisionneeds to be made on a case-by-casebasis. There are general guidelines,however. It is usually better to buyland that is connected to other pro-tected areas so bigger “islands” arecreated. It is also a good idea to con-nect protected areas with corridors.Habitat corridors are natural stripsthat allow the migration of organismsfrom one area to another. Corridorscan help overcome some of the prob-lems of habitat fragmentation.

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Concept DevelopmentPoint out that sustainable useoften leads to conflicts. Somepeople want access to more of aresource, while others may thinkthat too much of a resource isbeing used. Ask students if theythink deer hunting should beallowed. If yes, should there belimits on how many deer are shot?How will these limits be estab-lished? Will everybody be happywith these limits?

Portfolio Explain how set-ting up a park in a communitymight protect the habitat of localanimals. How might a new parkthreaten an existing habitat?


Conservation of Soil Soil is an important natural resourceand should be conserved. How does one conserve soil? As astart, we should be aware of factors that promote or speedup its unnecessary loss or erosion.

Procedure! Copy the data table below.

@ Measure 200 mL ofwater in a beaker.

# Fill a plastic tray withsoil as shown in thediagram.

$ Pour the water ontothe soil, tilting the trayand placing a dishunderneath the end ofit as indicated in thediagram.

% Wait several minutes for all water and soil to drain intothe dish.

^ Pour the soil and water from the dish into a graduatedcylinder. Wait several minutes for the soil and water to set-tle. Measure the volume of soil and water that washed oreroded into the dish. Record these values in your data table.

& Repeat steps 2-6, only this time place a section of soil inwhich grass is growing onto the tray. CAUTION: Alwayswash your hands with soap and water after workingwith soil.

Analysis1. What part of the experiment simulated soil erosion?2. Based on this experiment, explain why farmers usually

plant unused fields with some type of crop cover.

MiniLab 5-2MiniLab 5-2 Experimenting

International Trade in EndangeredSpecies (CITES) has established listsof species for which internationaltrade is prohibited or controlled. Thisagreement has been endorsed bymore than 120 countries.

Preserving habitatsAnother conservation biology

approach focuses on protectingwhole communities and wholeecosystems as the best way to con-serve species. An effective way to dothis is by creating nature preserves.The United States established its firstnational park—Yellowstone NationalPark—in 1872. You might look atYellowstone, Figure 5.11, and thinkof bear, elk, bison, and moose; how-ever, the park was created to preservethe unique geology of the area, notits biodiversity. Back in 1872, bear,bison, moose, and elk were widelydistributed across the United Statesas far east as Pennsylvania. As thehuman population in Americaexpanded, large parks such asYellowstone preserved habitats andprevented the extinction of manyspecies.

Establishing parks and other pro-tected areas can be an effective wayto preserve an ecosystem and thecommunities of species that livethere. Yet, only 6 percent of Earth’sland surface is protected in this way.Although this is only a small fractionof our planet’s land, these areas con-tain a large amount of biodiversity.For example, in Zaire, Africa, only3.9 percent of the land is protected,but 89 percent of Zaire’s bird speciesare found there. Because the biggestthreat to biodiversity is habitat loss,preserving land is an effective meansof preserving species.

Saying an area is protected does notautomatically make all species safe.Parks and protected areas often hirepeople, such as rangers, to manage theparks and ensure the protection oforganisms. In some areas, access bypeople is restricted. In other lands,people can harvest food or obtainmaterials but this use is managed. Thephilosophy of sustainable use strives


Source of sample

Volume oferoded soil

Volume of collected water

Volume oforiginal water

Bare soil

Soil with grass

Data Table

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2 Teach

Purpose Students will determine that soilerosion is reduced on land areaswith vegetation compared withland areas with no vegetation.

Process Skillscompare and contrast, draw aconclusion, interpret data, mea-sure in SI, recognize cause andeffect, formulate a model

Safety PrecautionsHave students wear a lab apronand safety goggles.

Teaching Strategies■ Obtain soil with grass growingin it from a lawn area (with per-mission) or purchase sod from agarden store.■ Try to keep the volume of soilequal in both trays. Water shouldbe poured slowly.■ Review the use of a graduatedcylinder for reading volumes.Remind students to allow the soilto settle after they pour it intothe cylinder. ■ You may wish to conduct thisactivity as a demonstration.

Expected ResultsThere will be less measured soilerosion when vegetation is pre-sent than when soil is bare.

Analysis1. water and soil draining into

the dish2. to reduce soil erosion

Knowledge Pull a smallplant from the ground and havestudents examine the root systemand the soil clinging to it. Havethem explain how roots reducesoil erosion. Use the PerformanceTask Assessment List for MakingObservations and Inferences inPASC, p. 17. L1

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MiniLab 5-2MiniLab 5-2

PortfolioPortfolio

Preserving Natural HabitatsLinguistic Have students research anational park. Ask them to record in

their portfolios the date it was estab-lished, its location, and common plantsand animals in the park.

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Hearing ImpairedVisual-Spatial Photocopy a map ofa country and a map of the same

region that shows protected areas. Giveboth maps to students. Have them color inthe protected areas on the unmarkedmap. Ask them to estimate what percentof the country’s land is protected.P

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Organized ConservationLinguistic Have studentsresearch a conservation group

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Use of Natural AreasHave students find out how natural areasin their region are identified and pro-tected. Who maintains them? What skillsand equipment are required to maintainthem? L2

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VIDEODISCThe Infinite VoyageSecrets from a Frozen

World, Global Awareness: Preserving the Environment (Ch. 9) 4 min.

The Infinite Voyage Life in the Balance, Biodiversity:Battling Extinction in the CostaRican Dry Forest (Ch. 7) 11 min. 30 sec.

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was banned, 50 birds were takenfrom Florida and put on Grand TerreIsland in Louisiana. The populationgrew and spread, and today over7000 brown pelicans live in the area.

Sometimes all the organisms inwild areas are gone, and the onlymembers of the species are in zoos.An organism that is held by people issaid to be in captivity. The ginkgotree, Figure 5.14, is an example of aspecies surviving extinction because itwas kept by people. The ginkgo is anancient tree; all similar speciesbecame extinct long ago. However,Chinese monks planted the ginkgotree around their temples. By keepingthese trees in “captivity,” they pre-vented the tree from becomingextinct. Ginkgos now add beauty tomodern cities. The ginkgo shows thatnot only can a species be protected,but that a protected species may beuseful to people.

The best place to keep plants is intheir natural ecosystems in the wild.If they must be kept in captivity, aneconomical way to do this is to storetheir seeds. Seeds can be cooled andstored for long periods of time. Byestablishing seed banks for threat-ened and endangered plants, thesespecies can be reintroduced if theybecome extinct.

Figure 5.14The ginkgo treewould probably beextinct if not for thecare given to it byChinese monks. It is abeautiful tree thatsurvives pollutionwell, making it agood tree for urbanlandscapes.

Section AssessmentSection Assessment

Understanding Main Ideas1. Contrast the fields of conservation biology and

ecology.2. Describe the U.S. Endangered Species Act. When

did it become law, and how does it help protector preserve endangered species?

3. What are the difficulties with reintroduction programs using captive-born animals?

4. Choose one species that you have read about,either here or in your library, and explain howconservation strategies lead to its recovery.

Thinking Critically5. Why is it necessary for a conservation biologist to

understand economics?

6. Recognizing Cause and Effect For a wildlifearea near you, what would be one use of thearea that fits into the philosophy of sustainableuse? What is one use that would damage theecosystem? For more help, refer to ThinkingCritically in the Skill Handbook.

SKILL REVIEWSKILL REVIEW

Reintroductions of captive animalsis more difficult than for plants.Keeping animals in captivity, withenough space, adequate care, andproper food, is expensive. Animalskept in captivity may lose the neces-sary behaviors to survive and repro-duce in the wild. Despite the difficul-ties involved, some species held incaptivity, such as the Arabian oryxand the California condor, have beensuccessfully reintroduced to theirnative habitats after becoming extinctin the wild.


3 AssessCheck for UnderstandingHave students explain which con-servation biology strategy they feelis the most important and why.

ReteachHave students list the three con-servation biology strategies inthis section. For each strategy,they should describe one organ-ism that was helped.

ExtensionVisual-Spatial Have studentscreate endangered species

posters. Each poster should havea picture, a description of theorganism’s niche, and what couldbe done to help the organism.

Portfolio Have studentswrite a letter to a local newspaperexpressing their views about pre-serving endangered species.

4 CloseDiscussionHold a class discussion aboutways that individuals can helpconserve biodiversity. Discussprograms and projects that can beundertaken by groups and com-munities to meet the same goal.

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Reintroduction programsThe year is 1992 in Wyoming. A

wildlife manager carries a cage with ablack-footed ferret, as shown inFigure 5.13. She opens the cagedoor, and the ferret cautiously steps


Is everyone pleased with conser-vation efforts? There havebeen many attempts to breedwild animals or move wildlifefrom one area to another. Thegoal is to preserve wildlifespecies if they appear to be indanger of extinction. Theseprograms may result from theEndangered Species Act. How dogroups with opposing interests oropinions view these programs?

AnalysisCase 1: In March 1998, the U.S. Fish and Wildlife Service

reintroduced 11 captive-bred Mexican gray wolves (Canuslupus baileyi) into parts of Arizona. They had been extinctfrom the area for 20 years. By law, ranchers are not allowedto kill native wolves. However, reintroduced wolves receivedspecial legal status under the Endangered Species Act andcan be killed by ranchers only if they threaten livestock.

Case 2: Gray wolves (Canus lupus) had been extirpatedfrom Yellowstone National Park since 1926. In 1995, the firstgroup of gray wolves was captured in Canada and introducedto Yellowstone National Park, nearly 30 years after beinglisted as endangered in the lower 48 states. Despite a pro-gram to compensate ranchers for livestock losses to wolves,legal pressure was mounted to have the wolves removed as athreat to livestock. In December 1997, a United States districtcourt ruled that the wolves should be removed from thepark. However, a nonprofit group called Defenders ofWildlife has appealed the decision and the fate of the wolvesremains with the courts.

Thinking Critically1. Should supporters of the Endangered Species Act be

pleased with the special legal status in Case 1? Explain.2. In Case 1, ranchers pointed out that they cannot tell rein-

troduced species from native wolves. Is their concern justi-fied? Explain your answer.

3. In Case 2, what is the main reason for the oppositionagainst wolves in the park? Explain your answer.

Problem-Solving Lab 5-2Problem-Solving Lab 5-2 Thinking Critically

Figure 5.13A black-footed ferret is reintroduced intoits native habitat in Wyoming. The care-giver wears a mask to reduce the chancesshe will transmit a human disease to theferret.

A gray wolf

out onto the land. Black-footed fer-rets used to live here, but the popula-tion declined steadily. Farmers hadpoisoned prairie dog colonies, think-ing that the prairie dogs were com-peting with their livestock for food.Prairie dogs are one of the ferret’smain foods. Black-footed ferret sur-vivors were captured and bred. Someof the ferrets that were released backto the land survived to reproduce.Reintroduction programs, such asthis one, release organisms into anarea where their species once lived.Form your own opinions about theseprograms by reading the Problem-Solving Lab. The factors that lead tothe decline of the organisms must beremoved if the reintroduction is to bea success. For example, the prairiedog population must be healthy forthe ferrets to survive.

The most successful reintroduc-tions occur when organisms are takenfrom an area and transported to anew suitable habitat. The brown peli-can was once common along theshores of the Gulf of Mexico. DDTcaused this bird’s eggs to break, andthe brown pelican completely disap-peared from these areas. After DDT

128

Purpose Students will explore opinionsregarding the preservation of cer-tain endangered species.

Process Skillsthink critically, analyze informa-tion, communicate, draw a con-clusion, recognize cause andeffect

Teaching Strategies■ You may wish to have teams ofvolunteers debate the issuesexplained in this lab.■ Remind students to showrespect for others’ opinions.

Thinking Critically

1. No. Ranchers may think thatany wolf they see is threaten-ing their livestock and kill it.

2. Yes. The native wolves prob-ably evolved from the rein-troduced species and mightlook similar to them.

3. They are killing ranchers’livestock.

Performance Have volun-teers give persuasive speeches toconvince “decision-makers” tocontinue reintroducing wolves orto end the program. Use thePerformance Assessment List forInvestigating an Issue Contro-versy in PASC, p. 65. L2

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Problem-Solving Lab 5-2Problem-Solving Lab 5-2

Revealing MisconceptionsStudents may not realize thatreintroduction is successful onlywhen the problems affecting thereintroduced species have beencorrected. For example, if urbansprawl led to the disappearance ofjaguars, reintroduced jaguarswould probably still not haveenough land to meet their needs.


Learning DisabledInterpersonal Organize studentsinto groups and have each group

draw a large protected area and a systemof several small protected areas. Thenhave the groups explain the advantagesand disadvantages of each.

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Section AssessmentSection AssessmentSection Assessment1. Conservation biology focuses on pro-

tecting biodiversity. Ecology is the studyof interactions in nature.

2. This 1973 law made it illegal to harmorganisms on the threatened or endan-gered species lists.

3. Captive-born animals are expensive to

raise and may lose their wild behaviors.4. Students might describe the California

condor being helped by reintroductionprograms or elephants being helped bybans on selling ivory.

5. Wildlife areas are often destroyed for economic reasons, so providing

economic reasons for their preservationis an important conservation strategy.

6. Hunting and nut collecting are exam-ples of sustainable use. Damage couldinclude building a mall or cutting treesfor lumber.

129

Resource ManagerResource ManagerContent Mastery, pp. 21, 23-24Reinforcement and Study Guide,

p. 22Tech Prep Applications, p. 7 L2

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Ginkgo leaves are distinctive.Bring in a few leaves so studentscan identify the tree.

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1. Defining Operationally What ismeant by the term domesticated?

2. Using the Internet Look at thefindings posted by other students.Which of the animals researchedwould make the best pet? Whichwould not be a wise choice?Why?

3. Interpreting Data What do youconsider the most importantinformation gained from yourresearch that:a. supports keeping your exotic

pet choice?b. does not support keeping your

exotic pet choice?4. Thinking Critically What posi-

tive contribution might be madeto the cause of conservation whenkeeping an exotic pet? Explain.

5. Thinking Critically How cankeeping exotic pets be a negativeinfluence on conservation biologyefforts?

6. Analyzing Information Whatare some reasons why zoos ratherthan individuals are better able tohandle exotic animals?

ANALYZE AND CONCLUDEANALYZE AND CONCLUDE

Sharing Your DataSharing Your Data

Find this BioLab on theGlencoe Science Web Site

at www.glencoe.com/sec/science. Post yourfindings in the data table provided for thisactivity. Use additional data from other students on the Internet to answer thequestions for this BioLab.

Exotic pet choice

Scientific name

Natural habitat (where found in nature)

Adult size

Dietary needs

Special health problems

Source of medical care, if needed

Safety issues for humans

Size of cage area needed

Special environmental needs

Social needs

Cost of purchase

Cost of maintaining (monthly estimate)

Care issues (high/low maintenance)

Additional information

Additional sources

Data Table

Category Response

A ferret

Iguanas

INTERNETINTERNET

131

W hat would it be like to own a pet like a snake or a ferret? Soundglamorous? Maybe it’s a lot of hard work for the owner and

maybe it’s not so fair to the pet. Use the Internet as a research tool tolocate information on exotic pets. Consider any animal as exotic if it isnot commonly domesticated and is not native to your area.

INTERNETINTERNET

■ Use the Internet to collect and com-pare information from other stu-dents.

■ Conclude if the animal you have chosen would or would not make agood pet.

Materials access to the Internet

PREPARATIONPREPARATION

1. Copy the data table and use it as aguide for the information to beresearched.

2. Pick an exotic pet from the fol-lowing list of choices: hedgehog,snake, ferret, large cat such astiger or panther, monkey, ape,iguana, tropical bird.

3. Go to the Glencoe Science WebSite to find links that will provideyou with information for thisBioLab. Note: You are not limitedto the pet suggestions provided. If a different organism appeals toyou, research it instead.

4. Record your findings in the datatable.

PROCEDUREPROCEDURE


Researching Information on Exotic Pets

Problem How can you use the Internet to

gather information on keeping an exotic animal as a pet?

ObjectivesIn this BioLab, you will: ■ Select one animal that is considered

an exotic pet.

A hedgehog

A rhesus monkey

Scarletmacaw

INTERNETINTERNET

Time Allotment If conducted at home, the activitywill require a 15-minute orienta-tion in class. If computers withInternet access are used in class,the activity will take one to twoperiods.

Process Skillsacquire information, collect data,compare and contrast, draw aconclusion, think critically, defineoperationally

Alternative Materials■ Use current magazines if

Internet access is not available.■ Arrange for a guest lecturer,

such as a veterinarian. Ask thespeaker to discuss the issue andprovide specific informationfor students to record in theirdata tables.

1. Domesticated means bred foran extended period of time incaptivity.

2. Answers will depend on theinformation students located.

ANALYZE AND CONCLUDEANALYZE AND CONCLUDE

PREPARATIONPREPARATION

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PROCEDUREPROCEDURE

Teaching Strategies■ Students with home computers andaccess to the Internet should be encouragedto complete this activity at home. Studentslacking access to computers can gain theinformation needed through articles in cur-rent periodicals.■ If necessary, review how to research atopic.

TroubleshootingStudents may need to be directed to narrowtheir searches or ignore certain web sites.

Data and ConclusionsStudent data and conclusions will differ,depending on the animals they researched,the web sites they visited, and other refer-ences they used.

3. a. Answers may include thatexotic pets are interesting,have a good market forresale, attract attention,and are challenging to raise.

b.Answers may include thatthese animals are expensiveand difficult to feed andcare for, including findingveterinarian services.

4. Answers may include thatkeeping these pets allows forpossible breeding, thus help-ing to save an endangeredspecies.

5. Students may note that buy-ing these pets endangersspecies even more by encour-aging black-market trade.

6. Zoos can better meet the ani-mals’ needs for food, shelter,and medical care.

Performance Ask volun-teers to debate this issue. Onegroup should support the keepingof exotic pets, and the othergroup should be opposed to theidea. Use the Performance TaskAssessment List for Investigatingan Issue Controversy in PASC,p. 65. L2

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Sharing Your DataSharing Your Data

To navigate tothe Inter-net

BioLabs, choose the Biology: TheDynamics of Life icon at theGlencoe Science Web Site. Clickon the student icon, then theBioLabs icon. Have studentsdetermine whether capture,breeding, and release programshave been successful for certainspecies of endangered animals.L2

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Chapter 5 AssessmentChapter 5 Assessment

SUMMARYSUMMARY

Section 5.1

Section 5.2

Main Ideas■ Biodiversity refers to the variety of life in an

area.■ The most common measure of biodiversity

is the number of species in an area.■ Extinctions occur when the last members of

species die.■ Human actions have resulted in habitat loss,

fragmentation, and degradation that hasaccelerated the rate of extinctions.

Vocabularyacid precipitation (p. 122)biodiversity (p. 115)edge effect (p. 122)endangered species (p. 120)exotic species (p. 124)extinction (p. 119)habitat degradation (p. 122)habitat fragmentation

(p. 121)ozone layer (p. 122)threatened species (p. 119)

Main Ideas■ Conservation biology is the study and imple-

mentation of methods to preserve Earth’sbiodiversity.

■ Legal protection of species and habitatpreservation have provided effective strate-gies in conservation biology.

■ Larger protected areas generally havegreater biodiversity than smaller protectedareas.

■ Animal reintroduction programs have beenmore successful when the reintroducedorganisms come from the wild rather thanfrom captivity.

Vocabularycaptivity (p. 129)conservation biology

(p. 125)habitat corridors (p. 127)reintroduction programs

(p. 128)sustainable use (p. 126)

CHAPTER 5 ASSESSMENT 133

1. In a study, aquatic ecologists counted thenumber of species in equal volumes of water.Where would you expect them to find thesmallest number of species? a. Lake Victoria, a very large tropical lake in

East Africab. the Great Barrier Reef, a coral reef off the

coast of Australiac. Lake Champlain, a large lake between

New York and Vermontd. coral reefs in the Red Sea, between Israel

and Egypt

UNDERSTANDING MAIN IDEASUNDERSTANDING MAIN IDEAS 2. The water hyacinth is from South America.People brought it to the waterways of Floridawhere it is growing out of control, killingnative water plants, and blocking the water-ways. The water hyacinth is a(n) ________species.a. threatened c. exoticb. extinct d. endangered

3. A protected wildlife area allows local hunters to shoot deer when their populationrises above a certain level. This is an exampleof ________.a. habitat degradation c. habitat lossb. habitat fragmentation d. sustainable use

VanishingSpecies

Conservationof Biodiversity

133


Resource ManagerResource ManagerChapter Assessment, pp. 25-30MindJogger VideoquizzesComputer Test BankBDOL Interactive CD-ROM, Chapter 5

quiz

Main IdeasSummary statements can be used bystudents to review the major con-cepts of the chapter.

Using the VocabularyTo reinforce chapter vocabulary, usethe Content Mastery Booklet andthe activities in the Interactive Tutorfor Biology: The Dynamics of Life onthe Glencoe Science Web Site.www.glencoe.com/sec/science

1. c2. c3. d

UNDERSTANDING MAIN IDEASUNDERSTANDING MAIN IDEAS

All ChapterAssessment

questions and answers have beenvalidated for accuracy and suitabil-ity by The Princeton Review.

Art Wolfe received a degree in fine arts from the University of Washington where he was

trained as a painter. He applied his knowledge of art and painting to become one of the

world’s best wildlife photographers. With morethan 1 million images to his credit, Wolfe’s photographs of Earth and its inhabitants

capture the best nature has to offer.

Although he has captured many an awesomelandscape on film, photographer Art Wolfe

is probably most well-known for his images ofwildlife. These include just about every organismfrom A to Z. Wolfe, for example, has traveled toAntarctica to photograph playful Adélie penguinsas they waddle across the ice sheet. Journeys tothe northern hemisphere brought Wolfe intocontact with brown bears, mule deer, and wolves.Treks to Africa have allowed the photographer tocapture the intricate patterns and symmetry ofzebras, both alone and in herds.

Capturing the moment Wolfe generally hasfour goals in mind when out on a shoot. One ofthe goals is to get as close as possible to his sub-ject. This, according to the artist, allows him tofreeze the instant of contact between himself andhis subject. Another of Wolfe’s goals is to try tocapture an animal in its natural surroundings.Says Wolfe of one of his images of a black bear, “ . . . habitat is as important as the animal.” Wolfe’sthird goal—to capture patterns in nature—is per-haps fueled by his knowledge of art and his admi-ration of the German artist, Martin Escher. Aphotograph of a herd of zebras taken from abovethe herd exemplifies this particular goal. His lastgoal while out on a shoot is to try to capture ananimal’s behavior. Among Wolfe’s photographsillustrating this goal are brown bears sparring ina cold Alaskan river, a Northern gannet meticu-lously constructing its nest, a snowy owl chickpracticing a fierce stare, and mule deer foragingin a grassy field somewhere in Montana.

Preserving nature for posterity Wolfe’s work has been seen by wide audiences. His photographs help people appreciate the naturalworld and want to protect it. In 1998, the NorthAmerican Nature Photography Associationawarded Wolfe its prestigious OutstandingPhotographer of the Year Award. That year,Wolfe also received the first Rachel CarsonAward presented by the National AudubonSociety for his work in calling attention to animals and habitats that are in danger of disappearing forever.


ConnectionArtArt

Connection Wildlife Photographyof Art Wolfe

Why is it important for wildlife to be pho-tographed by Art Wolfe and others?

To find out more about endan-gered species, visit the Glencoe

Science Web Site. www.glencoe.com/sec/science

CONNECTION TO BIOLOGYCONNECTION TO BIOLOGY

Snowy owl chick

132

PurposeStudents will learn about arenowned photographer and hisunique way of “preserving” nature—in photographs.

Teaching Strategies■ Obtain some of Wolfe’s booksfrom a library and encourage theclass to study the photographs.Have students each choose afavorite photograph and explaintheir choice. Challenge studentsto classify several photographswith respect to Wolfe’s goalswhile he is on location.■ Have students search the webto find a current list of endan-gered species. Have them identifywhich of Wolfe’s subjects areendangered.

Connection to BiologyWildlife photographs captureinteresting phenomena of natureas well as document what mightnot exist in the future.

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Connection

Internet Address Book

Note Internet addresses that you find useful in the spacebelow for quick reference. VIDEOTAPE

MindJogger VideoquizzesChapter 5: Biological Diversity andConservationHave students work in groups as they playthe videoquiz game to review key chapterconcepts.




CHAPTER 5 ASSESSMENT 135

20. ________ ________ release organisms into anarea where the species was once found.

21. Why is habitat loss such a big threat to biodi-versity?

22. How do habitat corridors help overcomesome problems with habitat fragmentation?

23. Would building a road across a wildernessarea, without building on the land, help pre-serve wild habitats? Explain your answer.

24. Recognizing Cause and Effect Using theidea of carrying capacity, design a plan forsustainable use of trout in a midwestern lakeby fishers.

25. Forming a Hypothesis Suggest reasons whylarge carnivores have a greater chance ofbecoming extinct than other organisms.Provide examples.

26. Concept Mapping Complete the conceptmap by using the following vocabulary terms:biodiversity, conservation biology, habitatdegradation, extinctions.

THINKING CRITICALLYTHINKING CRITICALLY

APPLYING MAIN IDEASAPPLYING MAIN IDEAS

ASSESSING KNOWLEDGE & SKILLSASSESSING KNOWLEDGE & SKILLS

Making and Using Graphs The graphbelow shows extinction rates for birds andmammals since 1600.

Use the graph to answer the following ques-tions.1. In what interval were there more extinc-

tions for mammals than for birds?a. 1600–1649 c. 1750–1799b. 1650–1699 d. 1850–1859

2. In what interval were there the mostmammal extinctions?a. 1600–1649 c. 1850–1999b. 1650–1699 d. 1900–1949

3. Approximately how many birds becameextinct in the interval 1650–1699?a. 7 c. 15b. 10 d. 20

4. Approximately how many birds becameextinct during the interval from1600–1949?a. 37 c. 115b. 70 d. 300

5. Predicting How many species of birdsand how many species of mammals doyou predict became extinct in the years1959–1999?

For additional review, use the assessmentoptions for this chapter found on the Biology: TheDynamics of Life Interactive CD-ROM and on theGlencoe Science Web Site.www.glencoe.com/sec/science

CD-ROM

1600-1649

1650-1699

1700-1749

1750-1799

1800-1849

1850-1899

1900-1949

40

30

20

10

Num

ber

of s

peci

es g

oing

ext

inct

Extinctions of Birds and Mammals

Birds

Mammals

decreases with

2.

1.

may result in

3.

4.

is protected by

135

21. Loss of habitat results in lessarea in which organisms can tryto meet their needs. As habitatsshrink, they support fewerspecies.

22. They allow the movement oforganisms between areas sothey can better meet theirneeds.

23. No, because the road wouldcause an edge effect and dividethe area into two smaller areas.

24. Any plan that limits the catch-ing of trout is acceptable. Plansinclude allowing harvesting of alimited number of trout, of cer-tain size trout, or only in certainseasons.

25. Reasonable hypotheses includethat carnivores need a greaterrange to obtain their prey sincethey are at a higher trophiclevel, that they depend on thehealthy existence of a largernumber of organisms, and thattheir large size makes themmore likely to be killed by peo-ple.

26. 1. Biodiversity; 2. Conservationbiology; 3. Habitat degradation;4. Extinctions

THINKING CRITICALLYTHINKING CRITICALLY

APPLYING MAIN IDEASAPPLYING MAIN IDEAS


1. a2. d3. b4. c5. Students might predict

an increase over the1900-1949 numbers, per-haps 45-50 species ofbirds and 40-45 species ofmammals.


4. If a researcher found that a higher incidenceof eye damage in kangaroos was due toincreased ultraviolet radiation hitting theEarth, which pollutant would most likely besuspected as the cause?a. sulfur dioxide c. ozoneb. chloroflourocarbons d. nitrogen dioxide

5. The California condor was extinct in thewild. Later they were bred in captivity andreleased in their old habitat. This is an exam-ple of: a. corridorsb. sustainable usec. an exotic speciesd. a reintroduction program

6. The federally funded project of building atelescope in Arizona was stopped because anendangered species was found on the land. This probably occurred due to:a. the Convention on International Trade in

Endangered Speciesb. reintroduction programsc. habitat fragmentationd. the U.S. Endangered Species Act

7. Two species of animals, Prezwalski’s horse and Pere David’s deer, no longer exist in the wild; they exist only in zoos. These species:a. would be classified as

a threatened speciesb. are making a

comebackc. exist only in captivityd. are extinct

8. A national park has four ways to have roadscross the park. Which method would pro-duce the least habitat fragmentation?

9. DDT was effective in killing insects.However, which organism was endangeredmost by its use?a. passenger pigeon c. elephantb. American bald eagle d. sea lamprey

10. The biggest threat to global biodiversity is:a. habitat degradation c. habitat lossb. habitat fragmentation d. exotic species

11. A branch of biology that seeks to preserve theworld’s biodiversity is ________ ________.

12. Allowing people to remove resources from aprotected area as long as damage is not doneto the ecosystem is an example of the philos-ophy of ________ ________.

13. The variety of life in an area is its ________.The number of ________ in the area usuallyprovides a measure of this.

14. Water pollution is an example of habitat________.

15. If Venus fly trap plants were planted in theirnative habitat, this could be part of a(n)________ program.

16. Rats came to Hawaii on European boats;their populations grew very quickly. The ratsare an example of a(n) ________ ________.

17. In Costa Rica, a thin strip of land links twoprotected wildlife areas. This is an example ofa(n) ________ ________.

18. The insecticide DDT caused the Americanbald eagle and peregrine falcon eggs to________, killing the chicks.

19. When a population of organisms falls drasti-cally, that species may become a(n) ________species. If its population falls almost to thepoint of extinction it is said to be a(n)________ species.

134 CHAPTER 5 ASSESSMENT

TEST–TAKING TIPTEST–TAKING TIP

Stumbling Is Not Falling Every once in a while you’ll hit a question that will completely throw you. It happens. You readthe question eight times over, and you still can’t understand it. Eliminate, guess, and thenmove on.

a. b. c. d.

134

4. b5. d6. d7. c8. b9. b

10. c11. conservation biology12. sustainable use13. biodiversity, species14. degradation15. reintroduction16. exotic species17. habitat corridor18. crack19. threatened, endangered20. Reintroduction programs



The water cycle, featuring evaporation fromlakes and oceans, condensation to produceclouds, and precipitation, provides an under-standing of how water flows through an ecosys-tem. Nitrogen and carbon also cycle throughecosystems. In the carbon cycle, plants producenutrients from carbon dioxide in the atmosphere.When these nutrients are broken down forenergy, carbon dioxide returns to the atmosphere.

Biotic FactorsThe ways organisms affect each other are

called biotic factors. Within a population of onespecies, parents nurture their young, and organ-isms compete for food or mates. Within a com-munity of species, organisms compete for needs,predators kill prey, and diseases spread.

Food for LifeOne of the most important ecological charac-

teristics of organisms is how they meet theirnutritional needs. Unlike animals that must eatother organisms to obtain their energy, plantsusually make their own food using the energyfrom the sun.

Autotrophs and HeterotrophsOrganisms that make their own food, such as

plants and algae, are called autotrophs.Organisms that cannot make their food must con-sume other organisms. These organisms are calledheterotrophs. Heterotrophs that consume onlyplants are called herbivores. Heterotrophs thatconsume only animals are called carnivores.Omnivores consume both plants and animals.

Energy FlowLife on Earth depends on energy from the

sun. Plants use this light energy to make food.Animals eat plants or other animals for food.

The path the nutrients and energy take canbe shown in a food chain such as:

rose ➔ aphid ➔ lady bugThis shows that the aphid eats the rose and

obtains its nutrients and energy. The ladybug eatsthe aphid and obtains its nutrients and energy.This food chain is a simple representation.Feeding relationships are often more complexand are represented with a food web.

Ecology

Commensalism In commensalism, onespecies benefits, while the other species is neitherhelped nor hurt. A cling fish hiding in the spines ofa sea urchin is commensalism. The cling fish hides inthe spines of the sea urchin to hide from predatorsbecause the sea urchin’s sting deters many organ-isms. The cling fish benefits from the relationship,but the sea urchin is not harmed.

Parasitism Another form of symbiosis is par-asitism, which exists when a smaller parasite gets itsnutrition from a larger host. The relationship bene-fits the parasite, and is harmful to the host.Examples of parasitism include mistletoe on a treeand a tapeworm in the intestines of a human.

137

BIODIGESTBIODIGEST

A tree is parasitized by mistletoe.

In photosynthesis, plants use nonlivingmaterials, including water, carbon dioxide,and light energy, to produce nutrients.

137

2 TeachReinforcement

Interpersonal Organize stu-dents into pairs. See how

many pairs can list five auto-trophs, five herbivores, five carni-vores, and five omnivores. L2

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BIODIGESTBIODIGEST

EcosystemsThe relationships among living things and how

the nonliving environment affects life are the keyaspects of ecology. An ecosystem is composed ofall the interactions among organisms and theirenvironment that occur within a defined space.

Abiotic InfluencesAround the world there are many types of

biomes, such as rain forests and grasslands. Thenonliving parts of the environment, called abioticfactors, influence life. For example, temperatureand precipitation influence the type of life in aterrestrial biome.

FOCUS ON ADAPTATIONSFOCUS ON ADAPTATIONS

Relationships formed betweenorganisms are important biotic fac-

tors in an environment. Adaptations,which can be physical structures orbehaviors, enable organisms to profitfrom relationships. In symbiosis, theclose relationship between two species,at least one species profits. There arethree categories of symbiosis thatdepend on whether the other speciesprofits, suffers, or is unaffected by therelationship.

Mutualism In mutualism, both speciesbenefit from their relationship. For example,bees have a mutualistic relationship withflowers. As the bee eats nectar from theflower, pollen becomes attached to the bee.The bee moves to another flower, and someof the pollen from the first flower pollinatesthe second flower. The bee gets food, andthe flower is able to reproduce.

Symbiosis

136

EcologyA n organism’s environment is the source for all its

needs and all its threats. Living things dependon their environments for food, water, and shelter. Yet,environments may contain things that can injure orkill organisms, such as diseases or predators. Ecology is the study of organisms in their environments.

For a preview of the ecology unit, study this BioDigest before you read the chapters.After you have studied the ecology chapters, you can use the BioDigest to review the unit.

BIODIGESTBIODIGEST

This coral reef’s survivalstrategies include methodsof obtaining needs andavoiding dangers.

Hot temperatures and littleprecipitation are abiotic factorsin this desert biome.

Bees pollinateflowers, andin return beesobtain nectar.

Cling fish hide in the spines of a sea urchin.

136

National Science Education StandardsUCP.I, UCP.3, UCP.4, C.3, C.4,C.5, C.6, F.2, F.4, F.5

PreparePurposeThis BioDigest can be used as anoverview for ecology. If time islimited, you may wish to use thisunit summary in place of thechapters in the Ecology unit.

Key ConceptsStudents learn about abiotic andbiotic factors in ecosystems. Theyare introduced to trophic levels,population growth, succession,and biodiversity.

1 FocusBellringer Before presenting the lesson,write the term food chain on thechalkboard. Then write theseterms with connecting arrows:rose ⇒ aphid ⇒ ladybug. Ask stu-dents what they think the arrowsshow. how one organism consumes ordepends on another; the movement ofmatter and energy

BIODIGESTBIODIGEST

MultipleLearningStyles

Look for the following logos for strategies that emphasize different learning modalities.

Kinesthetic Meeting IndividualNeeds, p. 138; Biology Journal,

p. 140Visual-Spatial Quick Demo, p. 137; Tech Prep, p. 139;

Interpersonal Reinforcement,p. 137Linguistic Portfolio, p. 138;Concept Development, p. 139;

Project, p. 140


Visual-Spatial Bring inand display a lichen.

Explain that this is an exampleof the symbiotic relationshipcalled mutualism. A species offungus and alga worktogether to form the lichenand allow it to survive on dry,barren rocks.

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Skill Have students make adiagram showing the flow ofwater in an ecosystem. L2

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Exploration: World BiomesDisc 1Video: SymbiosisDisc 1 Assessment PlannerAssessment Planner

Portfolio AssessmentPortfolio, TWE, p. 138

Performance AssessmentAssessment, TWE, p. 140

Knowledge AssessmentBioDigest Assessment, SE, p. 141

Skill AssessmentAssessment, TWE, p. 137

VIDEODISCBiology: The Dynamicsof Life

Symbiosis (Ch. 5)Disc 1, Side 1, 37 sec.


BioQuest: Antarctic Food WebDisc 1

!7^É"

Population SizeA population is defined as the number of

organisms of one species living in an area. Thesize of a population is influenced by the environ-ment. For example, a lack of food could limit thenumber of organisms. Other limiting factors inpopulation growth are water, shelter, and space.As population size increases, competition forsome needed items intensifies.

Carrying CapacityThe maximum population size an environ-

ment can support is called its carrying capacity. If the population size rises above the carryingcapacity, organisms die because they cannot meetall their needs.

Exponential GrowthIf a population had no predators, and the

organisms were able to satisfy their needs, popu-lation size would grow quickly. This fast growth iscalled exponential growth. This exponentialgrowth cannot continue forever; at some point,some need will be scarce and become a limitingfactor in the population’s growth.

Ecology

In Soil After land is disturbed,such as after a fierce forest fire, pio-neer species appear. Most pioneerplants produce many small seeds thatare dispersed over wide areas, so thatwhen land is disturbed, the seeds willbe there, ready to grow. Anothercharacteristic of pioneer species isthey tend to grow and reproducequickly. When a fresh patch of soil isdisturbed, pioneer species sprout,grow quickly, and produce many newseeds to colonize other areas. Finally,pioneer species tend to like much sunand they tend to be robust.

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BIODIGESTBIODIGEST

Dandelions are effective pioneerspecies because they grow fastand disperse many seeds.

Trees provide shade, whichfavors the growth of ferns.

Animals often die due todisease or lack of food

if population sizeexceeds carry-

ing capacity.

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Revealing MisconceptionsHelp students realize that a popu-lation refers to the number of or-ganisms of one species in a givenarea.

Concept DevelopmentLinguistic Ask students todescribe some needs that an

organism might not be able tomeet if its population rises toohigh.

EnrichmentExplain that exponential growthresults in a J-shaped curve.Exponential growth that levelsoff as a population rises to its carrying capacity results in an S-shaped curve.

Revealing MisconceptionsMake sure that students realizethat, although humans haveincreased the rates of extinctionfor other species, some extinc-tions are a natural process. Forexample, dinosaurs were extinctbefore humans walked on Earth.

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BIODIGESTBIODIGESTTrophic Levels

Nutrients and energy move from autotroph to herbivore to carnivore. Each of these layers iscalled a trophic level. If a forest area were ropedoff and three piles created—autotrophs, herbi-vores, and carnivores, the autotroph pile wouldbe larger than the herbivore pile, which wouldbe larger than the carnivore pile. The mass ofthe piles indicates the biological mass, or bio-mass, of the three trophic levels. The mass of autotrophs is usually about ten times themass of the herbivores, and the mass of the herbivores is about ten times the mass of the carnivores.

In a stable ecosystem, the biomass of plants must be greater than the bio-mass of herbivores. If the herbivoreswere more abundant then the plants,all the plants would be consumedand the herbivores would die.Likewise, if carnivores outnumbered herbi-vores, there would not be enoughfood for the carnivores.

FOCUS ON ADAPTATIONSFOCUS ON ADAPTATIONS

The first organisms to colonizenew areas are pioneer species.

Rocky areas, such as land recentlycovered by a lava flow, have differ-ent pioneer species than areas thatalready have soil. Rocky areas areusually first colonized by lichens.

On Rock Lichens are made oftwo organisms, a species of fungusand a species of photosyntheticalgae or bacteria. The fungus holds

its photosynthetic partner betweenthick fiber layers, allowing justenough light to penetrate to allowphotosynthesis without drying outthe lichen. The fungus provides atough case and the photosyntheticpartner supplies nutrition. Throughthis mutualistic relationship, lichensare able to survive in the harshestof climates such as high on moun-tains, in cold arctic regions, and inhot deserts.

Pioneer Species

Ecology

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As lichens grow, theybreak down rocksand produce soil.

Biomass of a 100m x 100m squaresection of deciduous forest.

VITAL STATISTICSVITAL STATISTICS

Vital StatisticsEnergy in a 100 x 100 m section of forest: Producers—24,055,000 kilocaloriesHerbivores—2,515,000 kilocaloriesCarnivores—235,000 kilocalories

Populations may bekept below theircarrying capacitydue to predation.

Carnivores

Herbivores

Producers

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EnrichmentAsk students to describe charac-teristics of effective predators.Then ask them to describe effec-tive prey. You might point outthat one interesting difference inmammals is that predators, suchas cheetahs, have eyes on thefront of their heads, while prey,such as antelopes, tend to haveeyes on the sides of their heads.

BIODIGESTBIODIGEST

PortfolioPortfolio

Describing PioneersLinguistic Ask students to writehow pioneer species on rock are dif-

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Visually ImpairedKinesthetic Cut three segments of 2 � 4 inch (5 � 10 cm) lumber,

10 inches (25 cm), 8 inches (20 cm), and 6 inches (15 cm) long. The first plank repre-sents the producers, the second the herbi-vores, and the third the carnivores. Havestudents manipulate the segments to under-stand a biomass pyramid.

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Encouraging PioneersVisual-Spatial In the schoolyard or anearby vacant lot, remove all plants

from a patch of soil that is about 1 yard (1 m) square. Have students draw picturesof the first plants that begin to grow inthe empty space.

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Knowledge Ask studentsto explain why there are moreherbivores than there are carni-vores. L2

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Exploration: Pyramid of EnergyDisc 1


Animation: Carrying CapacityDisc 1

VIDEODISCBiology: The Dynamicsof Life

Carrying Capacity (Ch. 13)Disc 1, Side 1, 17 sec.

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Ecology

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BIODIGEST ASSESSMENTBIODIGEST ASSESSMENT

Understanding Main Ideas1. A species of fluke called Schistoma lives

and obtains nutrients from cells in thehuman bladder. It produces about 300 to 3 000 eggs per day. This is an example of: a. mutualism c. commensalismb. parasitism d. extinction

2. Evaporation, condensation, and precipita-tion are all part of the ________ cycle.a. carbon c. nitrogenb. water d. biomass

3. Which of the following is an abiotic factorin an ecosystem?a. amount of light receivedb. number of predatorsc. the biomass of the aread. the number of endangered species

4. You observe an animal. It "oinks," eatsplants, and eats insects. It is probably:a. a producer c. an autotrophb. a herbivore d. an omnivore

5. You are on land that has very warm temperatures and little rain. This biome is most likely a:a. deciduous forest c. desertb. tropical rain forest d. grassland

6. You sample an area and find the biomassof the producers is 3 143 kilograms andthe biomass of carnivores is 37 kilograms.Which number is the best estimate for thebiomass of herbivores in the same area?a. 4.1 kilograms c. 39 kilogramsb. 299 kilograms d. 32 128 kilograms

7. You played in a meadow as a child. Whenyou visit the area again as an adult, it is aforest. Which of the following accounts forthe change?a. extinction of speciesb. ecological successionc. pyramid of biomassd. carrying capacity

Thinking Critically1. Describe how a specific abiotic factor and

a specific biotic factor could affect the lifeof a deer.

2. Explain the difference between commen-salism and mutualism.

3. Is a lichen more of a heterotroph or moreof an autotroph? Explain your answer.

4. What eventually happens to a populationexperiencing exponential growth? Why?

Biodiversityadds beautyto our planet.The livingworld alsoprovides oxy-gen and foodand materialsfor clothes,drugs, andbuildings.

BiodiversityIn succession, the species living in an ecosys-

tem change over time. Earth’s biosphere, the partof our planet that supports life, has experiencedchanges over time. As new forms of life evolved,other species became extinct.

Some ecosystems took millions of years toform. Millions of different organisms evolved tolive in these areas. They are rich in biologicaldiversity, or biodiversity. The most common mea-sure of biodiversity is the number of species thatlive in an area.

Earth’s biodiversity is facing a new crisis dueto a new dominant animal—people. As land isconverted for human use, organisms lose theirhabitat and the likelihood of extinctions increases.

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4 CloseActivityHave students make conceptmaps of these groups of terms.

a. parasitism, symbiosis, mutu-alism, commensalism

b. carrying capacity, populationsize, exponential growth

BIODIGESTBIODIGEST

BIODIGEST ASSESSMENTBIODIGEST ASSESSMENT

1. b 3. a 5. c 7. b2. b 4. d 6. b

Thinking Critically1. Answers will vary. Abiotic factors could

include temperature, precipitation, andsunlight. Biotic factors could include plants,predators, and parasites.

2. In commensalism, one organism benefitsand the other is neither helped nor hurt. Inmutualism, both organisms benefit.

3. Since lichens don’t consume other organ-isms, they are more autotrophic than het-erotrophic.

4. Growth slows as the population reaches itscarrying capacity.

Succession: Changes in a Community

What would happen if a farmer decided toquit farming a plot of land? No doubt, one of thefirst things to grow in the land would be thosepesky weeds that the farmer had been fightingfor years. These weeds are pioneer species, thefirst organisms to thrive in the new environment.

Changing SpeciesAfter the weeds take hold, other plants

appear, including annual flowers, grasses, andthen bushes. These provide shade, so now when atree seed germinates, it receives protection fromthe hot, drying sun. As the tree saplings grow,they block the sun from theplants underneath. The pioneerplants and the annual flowers,without the strong light theyneed, begin to die back. The

changes that take place are called ecological suc-cession. As species appear, they change theecosystem and help create conditions suitable forother organisms.

Ecology

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The most dramatic exam-ples of extinctions are thedinosaurs. When theylived on Earth, they werethe dominant animals, andnow they are all extinct.

The California condoris one of many speciesthreatened withextinction.

VITAL STATISTICSVITAL STATISTICS

Extinction EstimatesShallow water mussels of the Tennessee RiverShoal—44 of original 68 species are extinct.Plant species extinct in the United States—200Plant species in the United States in danger ofextinction—680Current loss from tropical rain forests—27,000species a year

After theextinction ofthe dinosaurs,mammals, suchas this woolymammoth,thrived.

Polacanthus

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3 AssessCheck for UnderstandingAsk students to compare andcontrast these terms.

a. autotrophs—heterotrophsb. population size—carrying

capacityc. pioneer species—succession

ReteachRemind students that populationis the number of organisms of aspecies in a given area. Have themcontrast population with biodi-versity—the number of species ina given area.

ExtensionAsk students to describe naturalconditions that could lead to suc-cession. volcanoes, floods, fires

Performance Ask studentsto research in groups and findnominees for the “toughest” pio-neer species. Have them presentarguments, in pro-wrestling styleposters, about why their nomineeis the toughest. L2

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BIODIGESTBIODIGEST


Preserving PioneersKinesthetic Encourage students tocreate a leaf press of one or two

common weeds in your area. Have themput these into their portfolios and explainwhy the weeds are good pioneer soilspecies.

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P R O J E C TChecking Theories

Linguistic Have students hypothe-size why a specific organism became

extinct and research whether most scien-tists agree with their hypotheses.P

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VIDEODISCSTV: BiodiversityDestroying Diversity

Unit 1, Side 1, 12 min. 15 sec.Destroying Diversity (in its entirety)

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VIDEODISCSTV: BiodiversityPreserving Diversity

Unit 2, Side 1, 12 min. 10 sec.Preserving Diversity (in its entirety)

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VIDEOTAPEThe Secret of Life

Gone Before You Know It: The Biodiversity Crisis


Content Mastery, pp. 25-28

Reinforcement and StudyGuide, pp. 23-24 L2

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chapter 5: biological diversity and conservation · chapter assessment, pp. 25-30 mindjogger...

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