b c b c b hippocrates what is biology? - · pdf filewhat is biology? what you’ll learn...
TRANSCRIPT
What isbiologyWhat Yoursquoll LearnChapter 1
Biology The Study of Life
Unit 1 ReviewBioDigest amp Standardized Test Practice
Why Itrsquos ImportantBiologists seek answers to questions about living thingsFor example a biologist might ask how plants such asCalifornia poppies convert sunlight into chemical energythat can be used by the plants to maintain life processesBiologists use many methods to answer their questionsabout life During this course you will gain an under-standing of the questions and answers of biology andhow the answers are learned
105Tsai Lun inventspaper as weknow it today
520 BCGreek philosophers proposethat the universe is composedof four elements earth airfire and water
Understanding the PhotoThis field of flowers represents not only a collectionof living things but also a community These plantsinteract with each other and form a biological com-munity that provides food nesting materials andoxygen for other living things
400 BCHippocratesfounds theprofession ofphysicians
350 BCThe first classificationof 500 species of ani-mals is created
Hippocrates
(t)Ed EcksteinCORBIS (crossover)Carr CliftonMinden Pictures
The following standards are covered in Unit 1B111 B116 B117 B118 B131 B138 B141 B143
Indiana Standards
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1452Gutenberg invents moveabletype allowing mass productionof printed materials
1895 X rays are dis-covered andthe first X rayof the humanbody is taken
2000The first draft ofthe HumanGenome Projectsequencing allhuman genes iscompleted
The first X ray
1687Isaac Newton pub-lishes Principiawhich details the first scientific methods
1863Lincoln delivers theGettysburg Address
1627Francis Baconpublishes workurging that theexperimentalmethod shouldplay a key rolein the develop-ment of scien-tific theories
BettmannCORBIS
xxvi-0001 UO1 BDOL-829900 8404 239 PM Page 1
What Yoursquoll Learn You will identify the charac-
teristics of life You will recognize how scien-
tific methods are used tostudy living things
Why Itrsquos ImportantRecognizing lifersquos characteristicsand the methods used to studylife provides a basis for under-standing the living world
Visit tobull study the entire chapter
onlinebull access Web Links for more
information and activities onbiology
bull review content with theInteractive Tutor and self-check quizzes
Biology The Study of Life
Biology The Study of Life
Even though the moose andplants pictured here appear tobe completely different fromeach other they share certaincharacteristics that make themboth living things Animals and plants as well as otherorganisms such as mushroomsand bacteria all exhibit thebasic characteristics of life
Understandingthe Photo
Roy Toft
2
inbdolglencoecom
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The Science of BiologyPeople have always been curious about living thingsmdashhow many dif-
ferent kinds there are where they live what they are like how they relateto each other and how they behave The concepts principles and theo-ries that allow people to understand the natural environment form thecore of biology the study of life What will you as a young biologistlearn about in your study of biology
A key aspect of biology is simply learning about the different types ofliving things around you With all the facts in biology textbooks youmight think that biologists have answered almost all the questions aboutlife Of course this is not true There are undoubtedly many life formsyet to be discovered many life forms havenrsquot even been named yet letalone studied Life on Earth includes not only the common organismsyou notice every day but also distinctive life forms that have unusualbehaviors
biology from theGreek words biosmeaning ldquoliferdquoand logos mean-ing ldquostudyrdquoBiology is thestudy of life
11 WHAT IS BIOLOGY 3
Characteristics Organism 1 Organism 3Organism 2
Make a Table As you read Chapter 1 list the characteristics of living things in the far left column Choose three organisms that seem different from each other and make notes in each column describing how each organism fulfills the requirements of a living thing
Characteristics of Living Things Make the following Foldable to help you organize information about the characteristics of living things
Fold a vertical sheet of paperin half from top to bottom twice
Fold the paper widthwise into six sections
Unfold lay the paper length-wise and draw lines along the folds
Label your table as shown
STEP 1
STEP 3
STEP 2
STEP 4
SECTION PREVIEWObjectivesRecognize some possiblebenefits from studyingbiologySummarize the character-istics of living things
New Vocabularybiologyorganismorganizationreproductionspeciesgrowthdevelopmentenvironmentstimulusresponsehomeostasisenergyadaptationevolution
11 What is biologyStandard B143 Understand that and describe how organisms are
influenced by a particular combination of living and nonliving components of the environmentIndiana Standards
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65493805
(tl)Steve KaufmanDRK Photo (tr)John GerlachDRK Photo (bl)Norbert WuMo Yung Productions (br)Jeffrey LeporePhoto Researchers
When studying the different typesof living things yoursquoll ask what whyand how questions about life Youmight ask ldquoWhy does this livingthing possess these particular fea-tures How do these features workrdquoThe answers to such questions lead tothe development of general biologicalprinciples and rules As strange assome forms of life may appear to bethere is order in the natural world
Biologists study the interactions of life
One of the most general principlesin biology is that living things do notexist in isolation they are all func-tioning parts in the delicate balance ofnature As you can see in Figure 11living things interact with their envi-ronment and depend upon other liv-ing and nonliving things to aid theirsurvival
4 BIOLOGY THE STUDY OF LIFE
Figure 11Questions about living things can sometimes be answered only byfinding out about their interactions with their surroundings
The seahorse is well hidden in its environment Itsbody shape blends in with the shapes of the seaweedsin which it lives
C The spadefoot toad burrows underground duringextended periods of dry weather and encases itself in awaterproof envelope to prevent water loss
D
Leaves of the insect-eating pitcher plant form a lip linedwith downward-pointing hairs that prevent insects fromescaping Trapped insects fall into a pool of water anddigestive juices at the bottom of the tube
BLeaf-cutter ants feed on fungus They carry bits ofleaves to their nest then chew the bits and formthem into moist balls on which the fungus grows
A
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(t)Bob Daemmrich (b)William J WeberVisuals Unlimited
Biologists Study theDiversity of Life
Many people study biology simplyfor the pleasure of learning about theworld of living things As yoursquove seenthe natural world is filled with exam-ples of living things that can be amus-ing or amazing and that challengeyour thinking Through your study ofbiology you will come to appreciatethe great diversity of life on Earth and the way all living organisms fitinto the dynamic pattern of life on ourplanet
Biologists study the interactionsof the environment
Because no living things includinghumans exist in isolation the studyof biology must include the investi-gation of living interactions Forexample learning about a populationof wild rabbits would require findingout what plants they eat and whatanimals prey on them The study ofone living thing always involves thestudy of the others with which itinteracts
Human existence too is closelyintertwined with the existence ofother organisms living on EarthPlants and animals supply us withfood and with raw materials likewood cotton and oil Plants alsoreplenish the essential oxygen in theair The students in Figure 12 arestudying organisms that live in a localstream Activities like this help pro-vide a thorough understanding of liv-ing things and the intricate web ofnature It is only through such knowl-edge that humans can expect tounderstand how to preserve the healthof our planet
Explain why scientists study an organismrsquos environment
Biologists study problems and propose solutions
The future of biology holds manyexciting promises Biological researchcan lead to advances in medical treat-ment and disease prevention inhumans and in other organisms Itcan reveal ways to help preserveorganisms that are in danger of disap-pearing and solve other problemslike the one described in Figure 13The study of biology will teach youhow humans function and how we fitin with the rest of the natural worldIt will also equip you with the knowl-edge you need to help sustain thisplanetrsquos web of life
11 WHAT IS BIOLOGY 5
Figure 12By understanding theinteractions of livingthings you will be bet-ter able to impact theplanet positively
Figure 13Honeybees and manyother insects are impor-tant to farmers becausethey pollinate the flowersof crop plants such asfruit trees In the 1990spopulations of many pol-linators declined raisingworries about reducedcrop yields
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(t)John SohldenVisuals Unlimited (b)Kjell B SandvedPhoto Researchers
Characteristics of Living Things
Most people feel confident thatthey can tell the difference between aliving thing and a nonliving thingbut sometimes itrsquos not so easy Inidentifying life you might ask ldquoDoesit move Does it grow Does it repro-ducerdquo These are all excellent ques-tions but consider a flame A flamecan move it can grow and it can pro-duce more flames Are flames alive
Biologists have formulated a list ofcharacteristics by which we can recog-nize living things Sometimes nonliv-ing things have one or more of lifersquoscharacteristics but only when some-thing has all of them can it then beconsidered living Anything that pos-sesses all of the characteristics of life isknown as an organism like the plantsshown in Figure 14 All living thingsbull have an orderly structurebull produce offspringbull grow and developbull adjust to changes in the
environmentPractice identifying the characteris-tics of life by carrying out theMiniLab on this page
6 BIOLOGY THE STUDY OF LIFE
Data Table
Prediction Life Characteristics
First None
Second
Third
Figure 14These plants are called Lithops from theGreek lithos meaning ldquostonerdquo Althoughthey donrsquot appear to be so Lithops are justas alive as elephants Both species possess allof the characteristics of life
Mildew
ObservePredicting Whether Mildew Is Alive What is mildew Is it alive We see it ldquogrowingrdquo on plastic shower curtains or on bathroom grout Does it show the character-istics associated with living things
Procedure Copy the data table below
Predict whether or not mildew is alive Record your prediction in the data table under ldquoFirst Predictionrdquo
Obtain a sample of mildew from your teacher Examine it for life characteristics Make a second prediction andrecord it in the data table along with any observed lifecharacteristics CAUTION Wash hands thoroughly afterhandling the mildew sample Do not handle the sample ifyou are allergic to mildew
$ Following your teacherrsquos directions prepare a wet mountof mildew for viewing under the microscope CAUTIONUse caution when working with a microscope microscopeslides and coverslips
Are there any life characteristics visible through the microscope that you could not see before Make a thirdprediction and include any observed life characteristics
Analysis 1 Describe Which life characteristics did you observe2 Interpret Data Compare your three predictions and
explain how your observations may have changed them3 Observe and Infer Explain the value of using scientific
tools to extend your powers of observation
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Living things are organizedWhen biologists search for signs of
life one of the first things they lookfor is structure Thatrsquos because theyknow that all living things show anorderly structure or organization
The living world is filled withorganisms All of them including theearthworm pictured in Figure 15are composed of one or more cellsEach cell contains the genetic mate-rial or DNA that provides all theinformation needed to control theorganismrsquos life processes
Although living things are verydiversemdashthere may be five to ten mil-lion species perhaps moremdashthey areunified in having cellular organiza-tion Whether an organism is madeup of one cell or billions of cells all ofits parts function together in anorderly living system
Living things make more living things
One of the most obvious of all thecharacteristics of life is reproductionthe production of offspring The litter of mice in Figure 16 is just
one example Organisms donrsquot liveforever For life to continue theymust replace themselves
Reproduction is not essential forthe survival of an individual organismbut it is essential for the continuationof the organismrsquos species (SPEE sheez)A species is a group of organisms thatcan interbreed and produce fertileoffspring in nature If individuals in aspecies never reproduced it wouldmean an end to that speciesrsquo existenceon Earth
Figure 15Like all organisms earth-worms are made up ofcells The cells form struc-tures that carry out essen-tial functions such asfeeding or digestion Theinteraction of these struc-tures and their functionsresult in a single orderlyliving organism
Figure 16A variety of mechanismsfor reproduction haveevolved that ensure thecontinuation of eachspecies Some organismsincluding mice producemany offspring in onelifetime
(t)OSFAnimals Animals (b)Tom McHughPhoto Researchers
7
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(t)Tom BeanDRK Photo (b)John GerlachDRK Photo
Living things change during their lives
An organismrsquos life begins as a singlecell and over time it grows and takeson the characteristics of its speciesGrowth results in an increase in theamount of living material and the for-mation of new structures
All organisms grow with differentparts of the organism growing at dif-ferent rates Organisms made up ofonly one cell may change little duringtheir lives but they do grow On theother hand organisms made up ofnumerous cells go through manychanges during their lifetimes such asthe changes that will take place in theyoung nestlings shown in Figure 17Think about some of the structuralchanges your body has already under-gone since you were born All of thechanges that take place during the lifeof an organism are known as itsdevelopment
Living things adjust to their surroundings
Organisms live in a constantinterface with their surroundings orenvironment which includes theair water weather temperature anyother organisms in the area andmany other factors For examplethe fox in Figure 18 feeds on small
8 BIOLOGY THE STUDY OF LIFE
Figure 17All life begins as a single cellAs cells multiply each organ-ism grows and develops andbegins to take on the charac-teristics that identify it as amember of a particular speciessuch as the owls shown here
Nature PreserveInterpreter
I f you like people as much as youlove nature you can combine
your skills and interests in a careeras a nature preserve interpreter
Skills for the JobInterpreters are also called nat-
uralists ecologists and environmental educators Theymight work for a nature preserve or a state or nationalpark where they give talks conduct tours offer video pre-sentations and teach special programs Some interpretersare required to have a degree in biology botany zoologyforestry environmental science education or a related fieldThey must also be skilled in communicating with others
Many interpreters begin as volunteers who have nodegrees just a love for what they do Over time volun-teers may become interns and eventually be hiredInterpreters often help restore natural habitats and protectexisting ones Part of their job is to make sure visitors donot harm these habitats and to point out the wonders ofthese natural areas
For example many tidepool organisms find protectionfrom too much sunlight by crawling under rocks A natural-ist can explain the importance of replacing rocks exactly asthey were found
For more careers in related fields visitinbdolglencoecomcareers
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(l)John GerlachDRK Photo (r)Tom BrakefieldDRK Photo
animals such as rabbits and miceThe fox responds to the presence ofa rabbit by quietly moving toward itthen pouncing Trees adjust to colddry winter weather by losing theirleaves Anything in an organismrsquosexternal or internal environmentthat causes the organism to react is astimulus A reaction to a stimulus isa response
The ability to respond to stimuli inthe environment is an importantcharacteristic of living things Itrsquos oneof the more obvious ones as wellThatrsquos because many of the structuresand behaviors that you see in organ-isms enable them to adjust to theenvironment Try the BioLab at theend of this chapter to find out moreabout how organisms respond toenvironmental stimuli
Regulation of an organismrsquos inter-nal environment to maintain condi-tions suitable for its survival is calledhomeostasis (hoh mee oh STAY sus)Homeostasis is a characteristic of lifebecause it is a process that occurs in allliving things Living things also useinternal feedback to respond to inter-nal changes For example organismsmust make constant adjustments to
maintain the correct amount of waterand minerals in their cells and theproper internal temperature Withoutthis ability to adjust to internalchanges organisms die
Living things reproduce them-selves grow and develop respond toexternal stimuli and maintain home-ostasis by using energy Energy is theability to cause change Organismsget their energy from food Plantsmake their own food whereas ani-mals fungi and other organisms gettheir food from plants or from organ-isms that consume plants
Living things adapt and evolveAny inherited structure behavior or
internal process that enables an organ-ism to respond to environmental factorsand live to produce offspring is calledan adaptation (a dap TAY shun)
Adaptations are inherited from previous generations There are alwayssome differences in the adaptations of individuals within any population of organisms As the environmentchanges some adaptations are moresuited to the new conditions than others Individuals with more suit-able adaptations are more likely to
11 WHAT IS BIOLOGY 9
Figure 18Living things respond to stimuli and makeadjustments to environmental conditions
Trees that drop their leaves in the fall conserve water andavoid freezing during winter
A
Keen senses of smell and hearing enable a fox to find prey Furallows foxes and othermammals to regulatebody temperatureDescribe What aresome other examplesof how feedback mechanisms help maintain homeostasis
B
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(l)Sam FriedPhoto Researchers (r)Renee LynnPhoto Researchers
survive and reproduce As a resultindividuals with these adaptationsbecome more numerous in the popula-tion Figure 19 shows some examplesof adaptation
The gradual change in a speciesthrough adaptations over time isevolution (e vuh LEW shun) Cluesto the way the present diversity oflife came about may be understoodthrough the study of evolution You
will study how the theory of evolutioncan help answer many of the questionspeople have about living things
As you learn more about Earthrsquosorganisms in this book reflect on thegeneral characteristics of life Ratherthan simply memorizing facts aboutorganisms or the vocabulary termstry to see how these facts and vocabu-lary are related to the characteristicsof living things
Understanding Main Ideas1 What are some important reasons for studying
biology
2 Identify and describe how an organism couldrespond to an external stimulus Describe aresponse to an internal stimulus
3 Why is energy required for living things How do living things obtain energy
4 Describe how biologistsrsquo research contributes toour understanding of the world
Thinking Critically5 Describe how energy and homeostasis are related
in living organisms
6 Observe and Infer Suppose you discover anunidentified object on your way home fromschool What characteristics would you study todetermine whether the object is a living or nonliv-ing thing For more help refer to Observe andInfer in the Skill Handbook
SKILL REVIEWSKILL REVIEW
10 BIOLOGY THE STUDY OF LIFE
Figure 19Living things adapt to their environments in a variety of ways
The desert Ocotillo has leaves onlyduring the rainy season Lacking leavesduring the dry season is an adaptationwhich helps conserve water
A
Manynocturnalanimals suchas this owlpossess largeeyes forefficient visionat night
B
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0003-0010 C01S1 BDOL-829900 8404 440 PM Page 10
MC ChamberlainDRK Photo
12 THE METHODS OF BIOLOGY 11
The Methods of Biology12
Observing and HypothesizingCuriosity is often what motivates biologists to try to answer simple
questions about everyday observations such as why earthworms leavetheir burrows after it rains Earthworms obtain oxygen through theirskin and will drown in waterlogged soil Sometimes answers to questionslike these also provide better understanding of general biological princi-ples and may even lead to practical applications such as the discovery thata certain plant can be used as a medicine The knowledge obtained whenscientists answer one question often generates other questions or provesuseful in solving other problems
The methods biologists useTo answer questions biologists may use many different approaches yet
there are some steps that are common to all approaches The commonsteps that biologists and other scientists use to gather information andanswer questions are collectively known as scientific methods
Scientific methods do not suggest a rigid approach to investigating and solving problems There are no fixed steps to follow yet scientific
SECTION PREVIEWObjectivesCompare different scien-tific methodsDifferentiate amonghypothesis theory andprinciple
Review Vocabularyenvironment an organismrsquos
surroundings (p 8)
New Vocabularyscientific methodshypothesisexperimentcontrolindependent variabledependent variablesafety symboldatatheory
Why does rain bring out the wormsUsing an Analogy Have you noticedthat moss grows only in shady moistlocations Or that earthworms crawl tothe surface after a rain If you have everwondered why moss grows in certainlocations or why earthworms appearafter a rain then you have used methodslike scientists use to develop experi-ments You might examine locationssuch as the one in the photo and makenotes on the environment in whichmoss grows Scientists use many differ-ent methods to answer questions but allscientific inquiries share some commonmethodsExperiment As you read the section useyour new knowledge of scientific methods toplan an investigative procedure to learn whymoss grows only in shady moist locations
Mosses are tiny plants that grow indense clumps
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84993506
Gerry EllisENP Images
hypothesis fromthe Greek wordshypo meaningldquounderrdquo and thesis meaning a ldquoplacingrdquo Ahypothesis is atestable explana-tion of a naturalphenomenon
Figure 110Brown tree snakes(Boiga irregularis) wereintroduced to Guammore than 50 yearsago Since then theirnumbers have increaseddramatically and theyhave severely reducedthe native bird popula-tion of the island
12
investigations generally involve mak-ing observations and collecting rele-vant information as well as using logicalreasoning and imagination to makepredictions and form explanationsScientific methods usually begin withscientists identifying a problem to solveby observing the world around them
The question of brown tree snakes
Have you ever been told that youhave excellent powers of observa-tion This is one trait that isrequired of biologists The story ofthe brown tree snake in Figure 110serves as an example During the1940s this species of snake was acci-dentally introduced to the island ofGuam from the Admiralty Islands inthe Pacific Ocean In 1965 it wasreported in a local newspaper thatthe snake might be considered bene-ficial to the island because it is apredator that feeds on rats miceand other small rodents Rodents areoften considered pests because theycarry disease and contaminate foodsupplies
Shortly after reading the newspaperreport a young biologist walkingthrough the forests of Guam made an
important observation She notedthat there were no bird
songs echoing throughthe forest Looking
into the trees shesaw a brown
tree snake
hanging from a branch After learningthat the bird population of Guam haddeclined rapidly since the introduc-tion of the snake she hypothesizedthat the snake might be eating thebirds A hypothesis (hi PAHTH us sus)is an explanation for a question or aproblem that can be formally testedHypothesizing is one of the methodsmost frequently used by scientists Ascientist who forms a hypothesis mustbe certain that it can be tested Untilthen he or she may propose sugges-tions to explain observations
As you can see from the brown treesnake example a hypothesis is not arandom guess Before a scientistmakes a hypothesis he or she hasdeveloped some idea of what theanswer to a question might be throughpersonal observations extensive read-ing or previous investigations
After stating a hypothesis a scien-tist may continue to make observa-tions and form additional hypothesesto account for the collected dataEventually the scientist may test ahypothesis by conducting an experi-ment The results of the experimentwill help the scientist draw a conclu-sion about whether or not thehypothesis is correct
ExperimentingPeople do not always use the word
experiment in their daily lives in thesame way scientists use it in theirwork As an example you may haveheard someone say that he or she wasgoing to experiment with a cookierecipe Perhaps the person is plan-ning to substitute raisins for choco-late chips use margarine instead ofbutter add cocoa powder reduce theamount of sugar and bake the cook-ies for a longer time This is not anexperiment in the scientific sensebecause there is no way to know what
0011-0018 C01S2 BDOL-829900 8304 200 PM Page 12
(t)The Ohio State UniversityOARDC (b)Tom BrakefieldDRK Photo
effect any one of the changes alonehas on the resulting cookies To a sci-entist an experiment is an investiga-tion that tests a hypothesis by theprocess of collecting informationunder controlled conditions
What is a controlled experiment Some experiments involve two
groups the control group and theexperimental group A control is thepart of an experiment that is thestandard against which results arecompared The control receives noexperimental treatment The experi-mental group is the test group thatreceives experimental treatment
Suppose you wanted to learn howfertilizer affects the growth of differ-ent varieties of soybean plants Yourhypothesis might state that the pres-ence of fertilizer will increase thegrowth rate of each plant variety Anexperimental setup designed to testthis hypothesis is shown in Figure111 Fertilizer is present in the soilof the experimental plants but notthe controls All other conditionsmdashincluding soil light and watermdasharethe same for both groups of plants
Designing an experimentIn a controlled experiment only
one condition is changed at a timeThe condition in an experiment thatis tested is the independent vari-able because it is the only factor thataffects the outcome of the experi-ment In the case of the soybeans the presence of fertilizer is the inde-pendent variable While testing theindependent variable the scientistobserves or measures a second condi-tion that results from the changeThis condition is the dependentvariable because any changes in itdepend on changes made to the inde-pendent variable In the soybeanexperiment the dependent variable
is the growth rate of the plantsControlled experiments are mostoften used in laboratory settings
However not all investigations arecontrolled Suppose you were on agroup of islands in the Pacific that isthe only nesting area for a large sea-bird known as a waved albatrossshown in Figure 112 Watching thenesting birds you observe that thefemale leaves the nest when her mateflies back from a foraging trip Thebirds take turns sitting on the eggs orcaring for the chicks often for twoweeks at a time You might hypothe-size that the birds fly around theisland or that they fly to some distantlocation in search of food To testthese hypotheses you might attach asatellite transmitter to some of thebirds and record their travels
Figure 112The waved albatross isa large bird that nestsmainly on Hood Islandin the GalaacutepagosIslands By tagging thebirds with satellitetransmitters scientistshave learned wherethese birds travel
Figure 111This experiment testedthe effect of fertilizeron the growth of sev-eral varieties of soy-beans For eachexperiment there arethree rows of each variety The center rows are the experi-mental plants Theouter rows are the controls Infer What isthe independentvariable in thisexperiment
12 THE METHODS OF BIOLOGY 13
0011-0018 C01S2 BDOL-829900 8304 201 PM Page 13
An investigation such as this whichhas no control is the type of biolog-ical investigation most often used infieldwork
The design of the procedure that isselected depends on what other inves-tigators have done and what informa-tion the biologist hopes to gainSometimes a biologist will design asecond investigation even while a firstone is being conducted to answer thequestion Try your hand at investiga-tion in the MiniLab on this page
Describe the rolesof a control independent variableand dependent variable
Using toolsTo carry out investigations scien-
tists need tools that enable them torecord information The growth rateof plants and the information fromsatellite transmitters placed on alba-trosses are examples of important infor-mation gained from investigations
Biologists use a variety of tools toobtain information in an investigationCommon tools include beakers testtubes hot plates petri dishes ther-mometers balances metric rulers andgraduated cylinders More complextools include microscopes centrifugesradiation detectors spectrophotome-ters DNA analyzers and gas chro-matographs Figure 113 shows somecomplex tools
Maintaining safety Safety is another important factor
that scientists consider when carryingout investigations Biologists try tominimize hazards to themselves thepeople working around them and theorganisms they are studying
In the investigations in this text-book you will be alerted to possiblesafety hazards by the safety symbolsshown in Table 11 and precautions
KS Studios
14 BIOLOGY THE STUDY OF LIFE
InvestigateTesting for Alcohol Promotional claims for certain over-the-counter prod-ucts may not tell you that one of theingredients is alcohol How can youverify whether or not a certain productcontains alcohol One way is to simplyrely on the information provided on aproduct label or an advertisementAnother way is to investigate and findout for yourself
Procedure
Copy the data table Draw three circles on a glass slide Label them A B and C
CAUTION Put on safety goggles Add one drop of water to circle A one drop of alcohol to
circle B and one drop of alcohol-testing chemical to circlesA B and C CAUTION Rinse immediately with water iftesting chemical gets on skin or clothing
$ Wait 2ndash3 minutes Note in the data table the color of eachliquid and the presence or absence of alcohol
Record the name of the first product to be tested^ Draw a circle on a clean glass slide Add one drop of the
product to the circleamp Add a drop of the alcohol-testing chemical to the circle
Wait 2ndash3 minutes Record the color of the liquid Repeat steps 5ndash7 for each product to be tested CAUTION
Wash your hands with soap and water immediately afterusing the alcohol-testing chemical
( Complete the last column of the data table If alcohol is present the liquid turns green deep green or blue A yellow or orange color means no alcohol is present
Analysis1 Infer Explain the purpose of using the alcohol-testing
chemical with water with a known alcohol and by itself2 Evaluate Which products did contain alcohol No alcohol
Data Table
Color of Liquid Alcohol Present
Circle A
Circle B
Circle C
Product name
Product name
0011-0018 C01S2 BDOL-829900 8304 201 PM Page 14
A safety symbol is a symbol thatwarns you about a danger that mayexist from chemicals electricity heator procedures you will use Refer to thesafety symbols at the back of this bookbefore beginning any field investiga-tion or lab activity in this text It is yourresponsibility to maintain the highestsafety standards to protect yourself aswell as your classmates
Data gatheringTo answer their questions about
scientific problems scientists seekinformation from their investigationsInformation obtained from investiga-tions is called data Sometimes thesedata are referred to as experimentalresults
Often data are in numerical formsuch as the distance covered in an alba-trossrsquos trip or the height that soybeanplants grow per day Numerical datamay be measurements of time temper-ature length mass area volume orother factors Numerical data may alsobe counts such as the number of beesthat visit a flower per day or the num-ber of wheat seeds that germinate atdifferent soil temperatures
Sometimes data are expressed inverbal form using words to describe
observations madeduring an investiga-tion Scientists who firstobserved the behavior of pandas inChina obtained data by recordingwhat these animals do in their natu-ral habitat and how they respond totheir environment Learning thatpandas are solitary animals withlarge territories helped scientistsunderstand how to provide bettercare for them in zoos and researchcenters
Having the data from an investiga-tion does not end the scientificprocess See how data collectionrelates to other important aspects ofresearch on pages 1060ndash1061 in theFocus On
(t)Robert Essel NYCCORBIS (b)Gerard MarePetit FormatPhoto Researchers
12 THE METHODS OF BIOLOGY 15
Figure 113Biologists use many tools in their studies
The opticalmicroscopemakes smalldetails visible
B
Gel electrophoresis can be used to produce aDNA fingerprint as shown Comparing DNAreveals how closely related two species are
A
Table 11 Safety Symbols
Sharp Object Safety This symbol appears when a danger of cuts or punctures caused by the use of sharp objects exists
Clothing Protection Safety This symbol appears whensubstances used could stain or burn clothing
Eye Safety This symbol appears when a danger to the eyesexists Safety goggles should be worn when this symbol appears
Chemical Safety This symbol appears when chemicals used can cause burns or are poisonous if absorbed through the skin
0011-0018 C01S2 BDOL-829900 8304 202 PM Page 15
KS Studios
Thinking about what happened Often the thinking that goes into
analyzing data takes the greatestamount of a scientistrsquos time Aftercareful review of the results the sci-entist must come to a conclusionWas the hypothesis supported by thedata Was it not supported Are moredata needed Data from an investiga-tion may be considered confirmedonly if repeating that investigationseveral times yields similar results Toreview how scientific methods areused in investigations see Figure 114on the next page
After analyzing the data scientistsoften have more questions than theyhad before the investigation Theycompare their results and conclusionswith the results of other studies byresearching the published literaturefor more information They alsobegin to think of other experimentsthey might carry out Are all theclaims you hear on TV commercialsbased on data gathered by scientificmethods Find out by conducting theProblem-Solving Lab here
Reporting results Results and conclusions of investi-
gations are reported in scientific jour-nals where they are available forexamination by other scientistsHundreds of scientific journals arepublished weekly or monthly In factscientists usually spend a large part oftheir time reading journal articles tokeep up with new information as it isreported The amount of informationpublished every day in scientific jour-nals is more than any single scientistcould read Fortunately scientists alsohave access to computer databasesthat contain summaries of scientificarticles both old and new
Verifying resultsData and conclusions are shared
with other scientists for an importantreason After results of an investiga-tion have been published other scien-tists can try to verify the results byrepeating the procedure If theyobtain similar results there is evenmore support for the hypothesisWhen a hypothesis is supported bydata from additional investigations itis considered valid and is generallyaccepted by the scientific communityWhen a scientist publishes the resultsof his or her investigation other sci-entists can relate their own work tothe published data
16 BIOLOGY THE STUDY OF LIFE
Analyze InformationAre promotional claims validrdquoOur product is new and improvedrdquo ldquoUse this mouthwash and your mouth will feel clean all dayrdquo Sound familiar TV and radio commercialsconstantly tell us how great certain products are Are these claims always based on facts
Solve the ProblemListen to or view a commercial for a product that addresses a medical problem such as heartburn allergies or bad breath If possible tape the commercial so that you can replay it as often asneeded Record the following information1 What is the major claim made in the commercial2 Is the claim based on experimentation3 What data if any are used to support the claim
Thinking Critically1 Evaluate In general was the promotional claim based
on scientific methods Explain your answer2 Evaluate In general are promotional claims made in
advertisements based on experimental evidence Explainyour answer
3 Experiment Plan an investigative procedure that could beconducted to establish promotional claims made for the product in your advertisement
0011-0018 C01S2 BDOL-829900 8304 202 PM Page 16
(t)S
cien
ce V
UV
isua
ls U
nlim
ited
(b)
KS
Stu
dios
Scientific MethodsFigure 114Scientific methods are used by scientists to answer questions and solveproblems The development of the cell theory one of the most usefultheories in biological science illustrates how the methods of science workIn 1665 Robert Hooke first observed cells in cork He made the drawing onthe right showing what he saw Critical Thinking What is the function ofother scientists in the scientific process
Observing The first step toward scientific discovery often takes placewhen a scientist observes something no one has noticed before After Hookersquosdiscovery other scientists observed cells in a variety of organisms
Making a hypothesis A hypothesis is a testable explanation or answer to a ques-tion In 1824 Reneacute Dutrochet hypothesized that cells are the basic unit of life
Collecting data Investigations and experiments test a hypothesis Data must be thor-oughly analyzed to determine whether the hypothesis was supported or disproved Fromthe results a conclusion can be formed Over the years scientists who used microscopes toexamine organisms found that cells are always present
Publishing results Results of an investigation are useful only if they are made avail-able to other scientists for a peer review Many scientists published their observations ofcells in the scientific literature Scientists will analyze the procedure examine the evidenceidentify faulty reasoning point out statements that go beyond the evidence and suggestalternative explanations for the same observations
Forming a theory A theory is a hypothesis that is supported by a large bodyof scientific evidence By 1839 many scientific observations supported thehypothesis that cells are fundamental to lifeThe hypothesis became a theory
Developing new hypotheses Anew theory may prompt scientists toask new questions or form additionalhypotheses In 1833 Robert Brownhypothesized that the nucleus is animportant control center of the cell
Revising the theoryTheories are revised as newinformation is gathered Thecell theory gave biologists astart for exploring the basicstructure and function ofall life Important discover-ies including the discov-ery of DNA have resulted
GG
FF
EE
DD
CC
BB
AA
Cork cells as drawnby Robert Hooke
0011-0018 C01S2 BDOL-829900 8304 203 PM Page 17
Gregory G DimijianPhoto Researchers
For example biologists studyingthe behavior of elephants in Africapublished their observations Otherscientists who were studying ele-phant communication used that datato help determine which of the ele-phantsrsquo behaviors are related to com-munication Further investigationsshowed that female elephants emitcertain sounds in order to attractmates and that some of the sounds
produced by bull elephants warnother males away from receptivefemales as described in Figure 115
Theories and lawsPeople use the word theory in
everyday life very differently from theway scientists use this word in theirwork You may have heard someonesay that he or she has a theory that aparticular football team will win theSuper Bowl this year What the per-son really means is that he or shebelieves one team will play better forsome reason Much more evidence isneeded to support a scientific theory
In science a hypothesis that is sup-ported by many separate observationsand investigations usually over a longperiod of time becomes a theory Atheory is an explanation of a naturalphenomenon that is supported by alarge body of scientific evidenceobtained from many different investi-gations and observations A theoryresults from continual verificationand refinement of a hypothesis
In addition to theories scientistsalso recognize certain natural lawsthat are generally known to be trueThe fact that a dropped apple falls to Earth is an illustration of the law of gravity
Understanding Main Ideas1 Suppose you observed that bees prefer a yellow
flower that produces more nectar over a purpleflower that produces less nectar List two separatehypotheses that you might make about bees andflowers
2 Describe a controlled experiment you couldperform to determine whether ants are moreattracted to butter or to honey
3 What is the difference between a theory and ahypothesis
4 Why do some investigations require a control
Thinking Critically5 Describe a way that a baker might conduct
a controlled experiment with a cookie recipe
6 Interpret Scientific Illustrations Review Figure 114 What happens when a hypothesis is not supported How does the strength of a scientific theory compare to the strength of a hypothesis For more help refer to Interpret Scientific Illustrations in the SkillHandbook
SKILL REVIEWSKILL REVIEW
Figure 115Investigations haveshown that male ele-phants communicatewith other males usingthreat postures andlow-frequency vibra-tions that warn rivalmales away
18 BIOLOGY THE STUDY OF LIFE inbdolglencoecomself_check_quiz
0011-0018 C01S2 BDOL-829900 8404 443 PM Page 18
Aaron Haupt
13SECTION PREVIEWObjectivesCompare and contrastquantitative and qualitativeinformationExplain why science andtechnology cannot solveall problems
Review Vocabularyexperiment procedure
that tests a hypothesis by collecting informa-tion (p 13)
New Vocabularyethicstechnology
13 THE NATURE OF BIOLOGY 19
Two Ways to Describe ThingsUsing Prior Knowledge How would youdescribe your homeroom class Wouldyou mention how many classmates youhave Or would you describe them asgood students Would you tellsomeone how many boys or howmany girls comprise the classPerhaps you would narrate howyour classmates carried out anexperiment Most information youcould give would be either quanti-tative or qualitative Quantitativeinformation uses numbers or meas-urements while qualitative informa-tion expresses qualities and behaviorOrganize Information Make a list of waysyou could describe your class Divide the list into two categories Quantitative and Qualitative
Kinds of InformationYou have learned that scientists use a variety of methods to test their
hypotheses about the natural world Scientific information can usually beclassified into one of two main types quantitative or qualitative
Quantitative informationBiologists sometimes conduct controlled experiments that result in
counts or measurementsmdashthat is numerical data These kinds of experi-ments occur in quantitative research The data are analyzed by compar-ing numerical values
Quantitative data may be used to make a graph or table Graphs andtables communicate large amounts of data in a form that is easy to under-stand Suppose for example that a biologist is studying the effects of cli-mate on freshwater life He or she may count the number of microscopicorganisms called Paramecium that survive at a given temperature Thisstudy is an example of quantitative research
The data obtained from the Paramecium study is presented as a graphin Figure 116 You can practice using graphs by carrying out theProblem-Solving Lab on the next page
This group of students can bedescribed with quantitative orqualitative information
The Nature of Biology
0019-0029 C01S3 BDOL-829900 8304 213 PM Page 19
BDOL-13
null
4322486
Measuring in the International System
It is important that scientificresearch be understandable to scien-tists around the world For examplewhat if scientists in the UnitedStates reported quantitative data ininches feet yards ounces poundspints quarts and gallons People inmany other countries would havetrouble understanding these databecause they are unfamiliar with theEnglish system of measurementInstead scientists always reportmeasurements in a form of the met-ric system called the InternationalSystem of Measurement commonlyknown as SI
One advantage of SI is that thereare only a few basic units and nearlyall measurements can be expressed inthese units or combinations of themThe greatest advantage is that SI likethe metric system is a decimal sys-tem Measurements can be expressedin multiples of tens or tenths of abasic unit by applying a standard setof prefixes to the unit In biology themetric units you will encounter mostoften are meter (length) gram (mass)
M AbbeyPhoto Researchers
Num
ber o
f par
amec
ia s
urvi
ving
Temperature
Paramecium Survival RatesFigure 116This graph shows how many parameciamdashmicroscopic organismsmdashsurvive as the tem-perature increases Infer What type ofinformation is represented by thegraph
ParameciumLM Magnification 65
20 BIOLOGY THE STUDY OF LIFE
Make and Use GraphsWhat can be learnedfrom a graph One wayto express information is topresent it in the form of agraph The amount of infor-mation available from agraph depends on thenature of the graph itself
Solve the ProblemStudy the graph at rightAnswer the questions that follow and note the type ofinformation that can and cannot be answered fromthe graph itself
Thinking Critically1 Observe Is there ever a
year in high school when all students are enrolled in physical education Explain your answer
2 Infer Is there a relationship between the number of students enrolled in physical education and their year ofhigh school Explain your answer
3 Observe Can you tell which states in the country have thelargest number of students enrolled in physical education
4 Infer Based on the graph can you explain why so few students take physical education in their senior year
US Students Enrolled in Physical Education
09 10 11 12
20
40
60
80
100
Grade
Perc
ent
MaleFemale
0019-0029 C01S3 BDOL-829900 8304 214 PM Page 20
(l)Art Wolfe (r)Luiz C MarigoPeter Arnold Inc
liter (volume) second (time) andCelsius degree (temperature) For athorough review of measurement inSI see Math and Problem-SolvingSkills in the Skill Handbook
Explain why scientists use the SI system
Qualitative information Do you think the behavior of the
animals shown in Figure 117 wouldbe easier to explain with numbers or with written descriptions of whatthe animals did Observational datamdashthat is written descriptions ofwhat scientists observemdashare oftenjust as important in the solution of a scientific problem as numerical data
When biologists use purely obser-vational data they are using qualitativeinformation Qualitative informationis useful because some phenomenaarenrsquot easily expressed as quantita-tive information For example thealbatross example on page 13 cannoteasily be illustrated with numbersPractice your investigative skills inthe MiniLab on the next page
Science and SocietyThe road to scientific discovery
includes making observations for-mulating hypotheses performing
investigations collecting and analyz-ing data drawing conclusions andreporting results in scientific jour-nals No matter what methods scien-tists choose their research oftenprovides society with importantinformation that can be put to prac-tical use
Maybe you have heard peopleblame scientists for the existence ofnuclear bombs or controversialdrugs To comprehend the nature ofscience in general and biology inparticular people must understandthat knowledge gained through scientific research is never inherentlygood or bad Notions of good andbad arise out of human social ethi-cal and moral concerns Ethicsrefers to the moral principles andvalues held by humans Scientistsmight not consider all the possibleapplications for the products of theirresearch when planning their inves-tigations Society as a whole musttake responsibility for the ethical useof scientific discoveries
Can science answer all questions
Some questions are simply not inthe realm of science Such questionsmay involve decisions regarding goodversus evil ugly versus beautiful orsimilar judgments There are also sci-entific questions that cannot be
13 THE NATURE OF BIOLOGY 21
Figure 117What kinds of information aregained by observing these animals
Penguins cannot fly They use theirwings for swimming in the oceansof the southern hemisphere
A
technology fromthe Greek wordstechne meaningan ldquoart or skillrdquoand logos mean-ing ldquostudyrdquo Tech-nology is theapplication of sci-ence in our dailylives
Toucans live in therain forests ofSouth America
B
0019-0029 C01S3 BDOL-829900 8304 215 PM Page 21
tested using scientific methodsHowever this does not mean thatthese questions are unimportant
Consider a particular questionthat is not testable Some peopleassert that if a black cat crosses yourpath you will have bad luck On thesurface that hypothesis appears tobe one that you could test But whatis bad luck and how long would youhave to wait for the bad luck tooccur How would you distinguishbetween bad luck caused by theblack cat and bad luck that occurs atrandom Once you examine thequestion you can see there is no wayto test it scientifically because youcannot devise a controlled experi-ment that would yield valid data
Can technology solve all problems
Science attempts to explain howand why things happen Scientificstudy that is carried out mainly forthe sake of knowledgemdashwith noimmediate interest in applying theresults to daily livingmdashis called purescience
However much of pure scienceeventually does have an impact onpeoplersquos lives Have you everthought about what it was like to livein the world before the developmentof water treatment plants vaccina-tions antibiotics or high-yieldingcrops These and other life-savingdevelopments such as the brain scanshown in Figure 118 are indirectresults of research done by scientistsin many different fields over hun-dreds of years
Other scientists work in researchthat has obvious and immediateapplications Technology (tek NAH
luh jee) is the application of scien-tific research to societyrsquos needs andproblems It is concerned with mak-ing improvements in human life and
22 BIOLOGY THE STUDY OF LIFEWill amp Deni McIntyrePhoto Researchers
Figure 118Technology allowsdoctors to developand use bettertools to diagnosemedical problems
Observe and InferHatching Dinosaurs Candy ldquodinosaur eggsrdquo can be found in specially marked packages of oatmeal You will conduct aninvestigation to determine what causes these pretend eggs to hatch
Procedure
Copy the data table above Observe the dinosaur eggs provided and record their
characteristics in your table Place an egg in each of two containers$ Form a hypothesis about the water temperature that will
cause the eggs to hatch Pour hot water into one container and cold water in the
other CAUTION Be careful with hot water Stir for oneminute Record your observations
Analysis1 Analyze Data Was your hypothesis supported How
would you revise it using the new information2 Experiment Design an experiment that would test either
heat or moisture as the variable What kind of quantita-tive data will you gather What will be your control Howmany trials will you run and how many eggs will you testIf time permits conduct your experiment
Data Table
Before Hot Water Cold WaterTreatment Treatment Treatment
Appearance after one minute
0019-0029 C01S3 BDOL-829900 8304 216 PM Page 22
Richard Hamilton SmithCORBIS
the world around us Technologyhas helped increase the productionof food reduced the amount ofmanual labor needed to make prod-ucts and raise crops and aided in thereduction of wastes and environ-mental pollution
The advance of technology hasbenefited humans in numerous waysbut it has also resulted in some seri-ous problems For example fertilizeris often used to boost the productionof food crops such as the cornshown in Figure 119 If more fertil-izer is applied than the plants areable to use the excess fertilizer canflow into streams or even oceansExcess nitrogen has been shown tocause problems with some coral reefsby promoting the growth of algae
Science and technology will neveranswer all of the questions we asknor will they solve all of our prob-lems However during your study ofbiology you will have many of yourquestions answered and you willexplore many new concepts As youlearn more about living thingsremember that you are a part of theliving world and you can use theprocesses of science to ask andanswer questions about that world
Understanding Main Ideas1 Why is it important that scientific investigations
be repeated What happens when other scientistsachieve different results when repeating an investigation
2 Compare and contrast quantitative and qualita-tive Explain how both types of information areimportant to biological studies
3 Why is science considered to be a combination ofinformation and process
4 Why is technology not the solution to all scientificproblems
Thinking Critically5 Biomedical research has led to the development of
technology that can keep ill or incapacitatedpatients alive How does this technology addressthe question of when such measures should beused on patients
6 Make and Use Graphs Look at the graph inFigure 116 Why do you think that the high-temperature side of the graph drops off more sharplythan the low-temperature side For more help referto Make and Use Graphs in the Skill Handbook
SKILL REVIEWSKILL REVIEW
13 THE NATURE OF BIOLOGY 23
Figure 119Technology allows farmers to use fertilizers that increase their crop pro-duction in order to meet the worldrsquos food needs Crop yields from thisfield of corn are maximized with the use of improved plant breeds andfertilizer in order to feed the worldrsquos growing population
inbdolglencoecomself_check_quiz
0019-0029 C01S3 BDOL-829900 8404 450 PM Page 23
Before YouBegin
Seeing different life formsand even interacting withthem is pretty much partof a typical day Petting adog swatting at a fly cut-ting the grass and talkingto your friends are com-mon examples But haveyou ever asked yourselfthe question ldquoWhat do allof these different lifeforms have in commonrdquo
24 BIOLOGY THE STUDY OF LIFE
Collecting Biological Data
ProblemWhat life characteristics can be observed in a pill bug
ObjectivesIn this BioLab you will Observe whether life characteristics are
present in a pill bug Measure the length of a pill bug Experiment to determine if a pill bug
responds to changes in its environment Use the Internet to collect and compare
data from other students
Materialspill bugs Armadillidium rulerwatch or classroom clock internet connectioncontainer glass or plastic pencil with dull point
Safety PrecautionsCAUTION Always wear goggles in the lab
Skill HandbookIf you need help with this lab refer to the Skill Handbook
1 Make copies of the data table andgraph outlines
2 Obtain a pill bug from your teacherand place it in a small container
3 Observe your pill bug to determine if it has an orderly structure Recordyour observations in the data table
4 Using millimeters measure andrecord the length of your pill bug inthe data table
5 Using your data and data from yourclassmates complete the graph ldquoPillBug Length Classroom Datardquo
PROCEDUREPROCEDURE
PREPARATIONPREPARATION
Time in SecondsTrial
Response to Environment
Orderly structure
Pill bug length in mm
1
2
3
4
5
Total
Average time
Organization and Growth and Development
Data Table
James H RobinsonPhoto Researchers
0019-0029 C01S3 BDOL-829900 8304 218 PM Page 24
ANALYZE AND CONCLUDEANALYZE AND CONCLUDE
13 THE NATURE OF BIOLOGY 25
6 Go to to post your data
7 Gently touch the underside of the pill bug with a dull pencil point CAUTION Use care to avoidinjuring the pill bug
8 Note its response and time in seconds how long the animalremains curled up Record the time in the data table as Trial 1
9 Repeat steps 7ndash8 four more times recording each trial in the data table
10 Calculate the average length of time your pill bug remains curled up
11 Post your data at
12 Wash your hands after working with pill bugs Return the pill bug to your teacher and suggest ways to release or reuse the bugs wisely
CLEANUP AND DISPOSAL
Length in millimeters1
10987654321
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Num
ber o
f pill
bug
s
Pill Bug Length Classroom Data
Length in millimeters1
100908070605040302010
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Num
ber o
f pill
bug
s
Pill Bug Length Internet Data
Response time in minutes2
100908070605040302010
4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40
Num
ber o
f pill
bug
s
Average Pill Bug Response Time Internet Data
inbdolglencoecom
inbdolglencoecominternet_lab
internet_lab
ANALYZE AND CONCLUDEANALYZE AND CONCLUDE
1 Think Critically Define the term ldquoorderlystructurerdquo Explain how this trait also pertainsto nonliving things
2 Use the Internet Explain how data from theclassroom and Internet graphs support theidea that pill bugs grow and develop
3 Interpret Data What was the most commonlength of time pill bugs remained curled inresponse to being touched
4 Draw a Conclusion Explain how theresponse to being touched is an adaptation
5 Experiment How might you design anexperiment to determine whether or not pillbugs reproduce
6 How might you collect oranalyze data to better define a living organismERROR ANALYSIS
inbdolglencoecominternet_lab
Find this BioLab using the link below andpost your data in the data table provided forthis activity Using the additional data fromother students on the Internet analyze thecombined data and complete your graphs
0019-0029 C01S3 BDOL-829900 8404 451 PM Page 25
26 BIOLOGY THE STUDY OF LIFE
The produce section of the supermarket has twobins of leafy lettuce that look very much alike
One is labeled ldquoorganicrdquo and has a higher priceMore and more consumers are willing to payextra for organically grown fruits vegetablesmeats and dairy products What are they payingthat extra money for
The term ldquoorganicrdquo usually refers to foodsthat are produced without the use of chemicalpesticides herbicides or fertilizers Organicfarmers use nonchemical methods to controlpests and encourage crop growth Beneficialinsects such as ladybugs and Trichogrammawasps are brought in to feed on aphids cater-pillars and other damaging insects Instead ofapplying herbicides organic farmers pull weedsby hand or by machine In place of fertilizersthey use composting and crop rotation toenrich the soil Organic farming is very laborintensive so organic foods are usually moreexpensive than those produced by conventionalmethods
Perspectives People usually buy organic prod-ucts because they want to be sure theyrsquore gettingnutritious food with no chemical residues Butthere are differences of opinion about how muchbetter organic food actually is and even whichfoods should be called organic
Is organic food healthier Agricultural chemicals can leave residues on food and contami-nate drinking water supplies Since exposure tosome chemicals is known to cause health prob-lems including cancer many consumers thinkthat organic foods are healthier Chemical pestcontrols kill beneficial organisms as well asunwanted pests and can adversely affect thehealth of other animals especially those thatfeed on insects Organic pest control methodsusually target specific pests and have little effecton beneficial organisms
Organic Food Is it healthier
(t)Jeff GreenbergVisuals Unlimited (b)KS Studios
Produce from an organic farm
Conventionally grownfood Low cost higher yield Chemicalfertilizers and pesticides make it possible togrow larger crops at lower cost which makesmore food available to more people Makingsure everyone can afford an adequate supply offruits and vegetables may be more importantthan the risk of disease posed by agriculturalchemicals
Not everyone agrees about what is organic andwhat isnrsquot Should genetically engineered plantor animal foods be considered organic Whatabout herbs or meats preserved by irradiationor lettuce and tomatoes fertilized with sewagesludge
inbdolglencoecombiology_society
Analyze the Issue Use resources to investigate your statersquos standards for labeling food products as ldquoorganicrdquo Look for research that shows that organically grown food is safer than conventionallygrown food Describe your findings in your sciencejournal
To find out more about organic food visit
0019-0029 C01S3 BDOL-829900 8404 453 PM Page 26
Section 11
(t)Steve E RossPhoto Researchers (c)Gerry EllisENP Images (b)Luiz C MarigoPeter Arnold Inc
Section 12
Section 13
Key Concepts Biology is the organized study of living
things and their interactions with theirnatural and physical environments
All living things have four characteristics incommon organization reproductiongrowth and development and the ability toadjust to the environment
Vocabularyadaptation (p 9)biology (p 3)development (p 8)energy (p 9)environment (p 8)evolution (p 10)growth (p 8)homeostasis (p 9)organism (p 6)organization (p 7)reproduction (p 7)response (p 9)species (p 7)stimulus (p 9)
What isbiology
Key Concepts Biologists use controlled experiments to
obtain data that either do or do not sup-port a hypothesis By publishing the resultsand conclusions of an experiment a scien-tist allows others to try to verify theresults Repeated verification over timeleads to the development of a theory
Scientific methods are used by scientists toanswer questions or solve problemsScientific methods include observing mak-ing a hypothesis collecting data publish-ing results forming a theory developingnew hypotheses and revising the theory
Vocabularycontrol (p 13)data (p 15)dependent variable
(p 13)experiment (p 13)hypothesis (p 12)independent variable
(p 13)safety symbol (p 15)scientific methods (p 11)theory (p 18)
Key Concepts Biologists do their work in laboratories
and in the field They collect both quanti-tative and qualitative data from theirexperiments and investigations
Scientists conduct investigations toincrease knowledge about the naturalworld Scientific results may help solvesome problems but not all
Vocabularyethics (p 21)technology (p 22)
The Methods ofBiology
The Nature ofBiology
CHAPTER 1 ASSESSMENT 27
STUDY GUIDESTUDY GUIDE
To help you review thecharacteristics of living things use theOrganizational Study Fold on page 3
inbdolglencoecomvocabulary_puzzlemaker
0019-0029 C01S3 BDOL-829900 8404 454 PM Page 27
Carolyn A McKeonePhoto Researchers
28 CHAPTER 1 ASSESSMENT
Review the Chapter 1 vocabulary words listed inthe Study Guide on page 27 Match the wordswith the definitions below
1 the application of scientific research to soci-etyrsquos needs and problems
2 any structure behavior or internal processthat enables an organism to respond to environmental factors and live to produceoffspring
3 anything that possesses all the characteristicsof life
4 a group of organisms that can interbreedand produce fertile offspring in nature
5 an explanation for a question or problemthat can be tested
6 Which of the following is not an appropriatequestion for science to considerA How many seals can a killer whale con-
sume in a dayB Which type of orchid flower is most
beautifulC What birds prefer seeds as a food sourceD When do hoofed mammals in Africa
migrate northward7 Similar-looking organisms such as the dogs
shown below that can interbreed and pro-duce fertile offspring are called ________A a living system C organizationB an adaptation D a species
8 If data from repeated experiments do notsupport the hypothesis what is the scientistrsquosnext stepA Declare the experiment unsuccessfulB Revise the hypothesisC Repeat the experimentD Overturn the theory
9 The single factor that is altered in anexperiment is the ________A controlB dependent variableC hypothesisD independent variable
10 Open Ended Describe how the human bodyshows the life characteristic of organization
11 Open Ended Scientists use quantitative datato derive mathematical models termed bio-metrics Research two definitions and uses ofbiometrics in todayrsquos society
12 Describe Explain the relationships among an organismrsquos environment adaptations andevolution
13 Interpret An experiment involves heatingchemicals in a test tube over a flame Whichof the safety symbols shown above should beused in the experiment Which symbol fromthe Skill Handbook is needed above butmissing from this table
14 Recently mem-bers of Congress have debated the issue ofhuman cloning Visit to investigate this debate Write an essayexpressing your opinion Use reasoningbased on your understanding of the debateto support your opinion Present your opin-ion in a debate with members of your class
REAL WORLD BIOCHALLENGE
Table 11 Safety Symbols
Sharp Object Safety This symbol appears when a danger ofcuts or punctures caused by the use of sharp objects exists
Clothing Protection Safety This symbol appears whensubstances used could stain or burn clothing
Eye Safety This symbol appears when a danger to the eyes exists Safety goggles should be worn when this symbol appears
Chemical Safety This symbol appears when chemicals used can cause burns or are poisonous if absorbed through the skin
inbdolglencoecom
inbdolglencoecomchapter_test
0019-0029 C01S3 BDOL-829900 8404 454 PM Page 28
CHAPTER 1 ASSESSMENT 29
Constructed ResponseGrid In
Record your answers on your answer document
21 Open Ended Why does a panel of doctors lawyers clergy and others sometimes convene todetermine if an experimental operation should be allowed on human patients
22 Open Ended Consider the following items a flame bubbles blown from a bubble wand and aballoon released into the air Describe characteristics of each that might indicate life and thosethat indicate they are not alive
inbdolglencoecomstandardized_test
Multiple Choice
A team of students measured the number of seedsthat germinated over ten days in a control group at18degC and in an experimental group at 25degC Theygraphed their data as shown above Study thegraph and answer questions 15ndash18
15 Which of the following best represents thehypothesis testedA Black seeds are bestB Seeds germinate faster at warmer
temperaturesC Fertilization of seeds requires heatD Seeds germinate when freezing
16 When did the experiment endA day 3 C day 7B day 6 D day 10
17 Which of the following was the independentvariableA kind of seedsB number germinatingC temperatureD time
18 Which of the following was the dependentvariableA kind of seedsB number germinatingC temperatureD time
Use the drawing below to answer question 19
19 In scientific investigations it is important tocollect data and make measurements with precision A graduatedcylinder is often used to measure volumes ofliquids accurately andprecisely The surface of many liquids in a graduated cylinder forms a curved surfacecalled a meniscus Whatis the volume of fluid inthe graduated cylinder shown on the rightA 79 mL C 81 mLB 80 mL D 75 mL
20 Which of the following statements is true ofa theoryA A theory is considered true and never
changesB A theory makes predictions about
unknown phenomenaC A theory is the same thing as a hypothesisD A theory is the usual outcome of an
experiment
Seed
s g
erm
inat
ed
Day
10
0
20
30
40
50
1 2 3 4 5 6 7 8 9 10
The Effect of Temperature on Germination
Experimental group
Control groupx x
x
x
x xx x x x
0019-0029 C01S3 BDOL-829900 8404 455 PM Page 29
What is biologyLiving things abound almost everywhere
on Earthmdashin deep ocean trenches atop the highest mountains in dry deserts and in wet tropical forests Biology is the study of living organisms and the interactions among them Biologists use a variety of scientific methods to study the details of life
30 BIODIGEST UNIT 1 REVIEW
Characteristics of LifeBiologists have formulated a list of characteris-
tics by which we can recognize living things
OrganizationAll living things are organized into cells
Organisms may be composed of one cell or manycells Cells are like rooms in a building You canthink of a many-celled organism as a building con-taining many rooms Groups of rooms in differentareas of the building are used for different pur-poses These areas are analogous to the tissuesorgans and body systems of plants and animals
HomeostasisA stable internal environment is necessary for
life Organisms maintain this stability throughhomeostasis which is a process that requires thecontrolled use of energy in cells Plants obtainenergy by converting light water and carbondioxide into food Other organisms obtain theirenergy indirectly from plants
Response to a StimulusLiving things respond to changes in their exter-
nal environment Any change such as a rise intemperature or the presence of food is a stimulus
Growth and DevelopmentWhen living things grow their cells enlarge and
divide As organisms age other changes also takeplace Development consists of the changes in anorganism that take place over time
ReproductionLiving things reproduce by transmitting their
hereditary information from one generation tothe next
Scientific MethodsScientists employ a variety of scientific methods
to investigate questions and solve problems Notall investigations will use all methods and theorder in which they are used will vary
ObservationCuriosity leads scientists to make observations
that raise questions about natural phenomena
HypothesisA statement that can be tested and presents a
possible solution to a question is a hypothesis
ExperimentAfter making a hypothesis the next step is to
test it An experiment is a formal method of test-ing a hypothesis In a controlled experiment twogroups are tested and all conditions except oneare kept the same for both groups The single con-dition that changes is the independent variableThe condition caused by the change in the inde-pendent variable is called the dependent variable
TheoryWhen a hypothesis has been confirmed by
many experiments it may become a theoryTheories explain natural phenomena
Arthur C TwomeyPhoto Researchers
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UNIT 1 STANDARDIZED TEST PRACTICE 31
Multiple Choice
1 The basic unit of organization of living thingsis a(n) ________A atom C cellB organism D organ
2 Storing and periodically releasing energyobtained from food is an example of ________A evolution C responseB homeostasis D growth
3 A hypothesis that is supported many times maybecome a(n) ________A experiment C theoryB conclusion D observation
4 All of the procedures scientists use to answerquestions are ________A life characteristics C researchB scientific methods D hypotheses
5 The environment includes ________A air water and weatherB response to a stimulusC adaptationsD evolution
6 Which of the following is NOT a testablehypothesisA Fertilizer A will make the KW variety of
green bean produce more beansB Smart people like the same musicC Vitamin C relieves cold symptomsD There is more than one species of African
elephant
Use the lab procedure below to answer questions 7 and 8
7 Which plot is the control groupA the first plot with traditional pesticideB the second plot with the new pesticideC the third plot with no pesticideD there is no control group
8 What could be concluded if the plot treated with the new pesticide has damage similar to the control plotA The experiment is a failureB The new pesticide may not be effectiveC The control plot was problematicD The new pesticide should be used
Constructed ResponseGrid In
Record your answers on your answer document
9 Open Ended List the characteristics youwould check to see if a pine tree is a livingthing Give an example that shows how thetree exhibits each characteristic
10 Open Ended Compare the characteristics oflife with the flames of a fire How are they sim-ilar and different
11 Open Ended Why do most experiments have acontrol Describe an experiment that does nothave a control
12 Open Ended Evaluate the impact that scientificresearch has on society
A group of scientists wishes to see if usinga new environmentally friendly pesticideis effective in preventing insect damageto soybeans Three different soybeanplots are planted The first plot containssoybeans treated with the traditional pes-ticide The second plot is treated with thenew environmentally friendly pesticideThe third plot is left untreated
Maximize Your ScoreAsk how your test will be scored In order to doyour best you need to know if there is a penaltyfor guessing and if so how much of a penalty Ifthere is no random-guessing penalty at all youshould always fill in an answer
End-of-Course Assessment Practice
inbdolglencoecomstandardized_test
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- Biology The Dynamics of LifemdashIndiana Edition
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- Contents in Brief
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- The Indiana Biology Handbook
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- Correlations to Indianas Academic Standards
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- Indianas Academic Standards to Biology The Dynamics of Life
- Biology The Dynamics of Life to Indianas Academic Standards
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- How to Master the Academic Standards
- End-of-Course Assessment Practice Countdown
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- Table of Contents
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- Unit 1 What is biology
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- Chapter 1 Biology The Study of Life
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- Section 11 What is biology
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- MiniLab 11 Predicting Whether Mildew Is Alive
- Careers in Biology Nature Preserve Interpreter
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- Section 12 The Methods of Biology
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- MiniLab 12 Testing for Alcohol
- Problem-Solving Lab 11
- Inside Story Scientific Methods
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- Section 13 The Nature of Biology
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- Problem-Solving Lab 12
- MiniLab 13 Hatching Dinosaurs
- Internet BioLab Collecting Biological Data
- Biology and Society Organic Food Is it healthier
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- Chapter 1 Assessment
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- BioDigest What is biology
- Unit 1 Standardized Test Practice
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- Unit 2 Ecology
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- Chapter 2 Principles of Ecology
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- Section 21 Organisms and Their Environment
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- MiniLab 21 Salt Tolerance of Seeds
- Problem-Solving Lab 21
- Careers in Biology Science Reporter
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- Section 22 Nutrition and Energy Flow
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- Problem-Solving Lab 22
- Physical Science Connection Conservation of Energy
- Physical Science Connection Conservation of Mass
- MiniLab 22 Detecting Carbon Dioxide
- Inside Story The Carbon Cycle
- Design Your Own BioLab How can one population affect another
- Biology and Society The EvergladesmdashRestoring an Ecosystem
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- Chapter 2 Assessment
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- Chapter 3 Communities and Biomes
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- Section 31 Communities
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- MiniLab 31 Looking at Lichens
- Problem-Solving Lab 31
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- Section 32 Biomes
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- Physical Science Connection Salinity and Density of a Solution
- Problem-Solving Lab 32
- MiniLab 32 Marine Plankton
- Inside Story A Tropical Rain Forest
- Investigate BioLab Succession in a Jar
- Connection to Literature Our National Parks by John Muir
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- Chapter 3 Assessment
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- Chapter 4 Population Biology
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- Section 41 Population Dynamics
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- MiniLab 41 Fruit Fly Population Growth
- Inside Story Population Growth
- Problem-Solving Lab 41
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- Section 42 Human Population
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- Problem-Solving Lab 42
- MiniLab 42 Doubling Time
- Investigate BioLab How can you determine the size of an animal population
- Connection to Chemistry Polymers for People
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- Chapter 4 Assessment
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- Chapter 5 Biological Diversity and Conservation
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- Section 51 Vanishing Species
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- MiniLab 51 Field Investigation
- Problem-Solving Lab 51
- Physical Science Connection Environmental Impact of Generating Electricity
- Physical Science Connection Wave Energy
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- Section 52 Conservation of Biodiversity
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- MiniLab 52 Conservation of Soil
- Problem-Solving Lab 52
- Internet BioLab Researching Information on Exotic Pets
- Connection to Art Photographing Life
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- Chapter 5 Assessment
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- BioDigest Ecology
- Unit 2 Standardized Test Practice
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- Unit 3 The Life of a Cell
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- Chapter 6 The Chemistry of Life
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- Section 61 Atoms and Their Interactions
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- Problem-Solving Lab 61
- Physical Science Connection Chemical Bonding and the Periodic Table
- Physical Science Connection Conservation of Mass in Chemical Reactions
- Careers in Biology WeedPest Control Technician
- MiniLab 61 Determine pH
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- Section 62 Water and Diffusion
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- Physical Science Connection The Structure of Water Molecules
- Physical Science Connection Density of Liquids
- Problem-Solving Lab 62
- MiniLab 62 Investigate the Rate of Diffusion
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- Section 63 Life Substances
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- Inside Story Action of Enzymes
- Design Your Own BioLab Does temperature affect an enzyme reaction
- BioTechnology The Good News and the Bad News About Cholesterol
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- Chapter 6 Assessment
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- Chapter 7 A View of the Cell
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- Section 71 The Discovery of Cells
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- Physical Science Connection Lenses and the Refraction of Light
- MiniLab 71 Measuring Objects Under a Microscope
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- Section 72 The Plasma Membrane
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- Problem-Solving Lab 71
- Physical Science Connection Solubility and the Nature of Solute and Solvent
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- Section 73 Eukaryotic Cell Structure
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- Problem-Solving Lab 72
- MiniLab 72 Cell Organelles
- Physical Science Connection Conservation of Energy
- Inside Story Comparing Animal and Plant Cells
- Investigate BioLab Observing and Comparing Different Cell Types
- Connection to Literature The Lives of a Cell by Lewis Thomas
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- Chapter 7 Assessment
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- Chapter 8 Cellular Transport and the Cell Cycle
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- Section 81 Cellular Transport
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- MiniLab 81 Cell Membrane Simulation
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- Section 82 Cell Growth and Reproduction
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- Problem-Solving Lab 81
- Problem-Solving Lab 82
- Inside Story Chromosome Structure
- MiniLab 82 Seeing Asters
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- Section 83 Control of the Cell Cycle
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- Problem-Solving Lab 83
- Investigate BioLab Where is mitosis most common
- Connection to Health Skin Cancer
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- Chapter 8 Assessment
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- Chapter 9 Energy in a Cell
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- Section 91 The Need for Energy
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- Problem-Solving Lab 91
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- Section 92 Photosynthesis Trapping the Suns Energy
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- MiniLab 91 Separating Pigments
- MiniLab 92 Use Isotopes to Understand Photosynthesis
- Inside Story The Calvin Cycle
- Biotechnology Careers Biochemist
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- Section 93 Getting Energy to Make ATP
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- Inside Story The Citric Acid Cycle
- Problem-Solving Lab 92
- MiniLab 93 Determine if Apple Juice Ferments
- Internet BioLab What factors influence photosynthesis
- Connection to Chemistry Plant Pigments
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- Chapter 9 Assessment
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- BioDigest The Life of a Cell
- Unit 3 Standardized Test Practice
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- Unit 4 Genetics
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- Chapter 10 Mendel and Meiosis
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- Section 101 Mendels Laws of Heredity
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- MiniLab 101 Looking at Pollen
- Problem-Solving Lab 101
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- Section 102 Meiosis
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- Problem-Solving Lab 102
- MiniLab 102 Modeling Crossing Over
- Inside Story Chromosome Mapping
- Internet BioLab How can phenotypes and genotypes of plants be determined
- Connection to Math A Solution from Ratios
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- Chapter 10 Assessment
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- Chapter 11 DNA and Genes
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- Section 111 DNA The Molecule of Heredity
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- Problem-Solving Lab 111
- Inside Story Copying DNA
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- Section 112 From DNA to Protein
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- Problem-Solving Lab 112
- MiniLab 111 Transcribe and Translate
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- Section 113 Genetic Changes
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- Physical Science Connection Gamma Radiation as a Wave
- Careers in Biology Genetic Counselor
- Problem-Solving Lab 113
- MiniLab 112 Gene Mutations and Proteins
- Investigate BioLab RNA Transcription
- BioTechnology Scanning Probe Microscopes
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- Chapter 11 Assessment
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- Chapter 12 Patterns of Heredity and Human Genetics
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- Section 121 Mendelian Inheritance of Human Traits
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- MiniLab 121 Illustrating a Pedigree
- Problem-Solving Lab 121
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- Section 122 When Heredity Follows Different Rules
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- Problem-Solving Lab 122
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- Section 123 Complex Inheritance of Human Traits
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- Inside Story The ABO Blood Group
- Problem-Solving Lab 123
- MiniLab 122 Detecting Colors and Patterns in Eyes
- Design Your Own BioLab What is the pattern of cytoplasmic inheritance
- Connection to Social Studies Queen Victoria and Royal Hemophilia
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- Chapter 12 Assessment
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- Chapter 13 Genetic Technology
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- Section 131 Applied Genetics
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- Problem-Solving Lab 131
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- Section 132 Recombinant DNA Technology
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- MiniLab 131 Matching Restriction Enzymes to Cleavage Sites
- Inside Story Gel Electrophoresis
- Problem-Solving Lab 132
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