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A scientist might make the hypothesis that the snakeswere the reason the number of birds decreased.A scientist who forms a hypothesis must be certain that it canbe tested. Before testing a hypothesis, scientists make observations and do research. The results of the experiment will help thescientist answer whether or not the hypothesis is supported.Make Flash Cards Makingflash cards is a good way tolearn chapter material. Foreach paragraph, think of aquestion your teacher mightask on a test.
Write the question on one side of the flashcard. Then write the answer onthe other side. Quiz yourselfuntil you know the answers.1. What is a hypothesis?________________________Experimenting________________________To a scientist, an experiment is a test of a hypothesis by collecting information under controlled conditions.________________________READING ESSENTIALSChapter 15NameDateClassSection1.2The Methods of Biology, continued2.
What are the twogroups in a controlledexperiment?________________________________________________Controlled experiments involve two groups—the controlgroup and the experimental or test group. The control is thepart of an experiment that represents the standard conditions.In other words, the control receives no experimental treatment.The experimental group is the test group that receives experimental treatment.For instance, imagine an experiment to learn how fertilizeraffects plant growth. Fertilizer would be used in the experimentalgroup but not in the control group. All other conditions—soil, light, and water—would be the samefor both groups.In this experiment, using fertilizer is the independent variable.
The independent variable isthe one condition in an experiment that is tested.How much the plants grow is the dependent variable. The dependent variable is the conditionthat changes because of a change in the independent variable.Safety is another important factor that scientiststhink about when carrying out investigations andexperiments.
It is important to know about dangersthat may exist from doing an experiment beforeyou begin it. Anyone doing an experiment has aresponsibility to follow safety procedures. Theymust keep themselves and others out of danger.How are theories formed?3. Who is responsible formaking sure that safetyprocedures are followedwhen conducting anexperiment?________________________________________________________________________6Chapter 1The information gathered from experiments is called data.A scientist carefully reviews or analyzes experimental results todecide if the data supports the hypothesis. Scientists repeat theirexperiments in order to gather more data. Data are consideredreliable only when repeating the experiment several times produces similar results.Scientists also compare the results of their experiments with theresults of other studies.
They research published information inscientific journals and computer databases. It is important to havedetails of an experiment presented in scientific journals and databases so scientists can compare their results with those of similarstudies. It lets other scientists test the results by repeating theexperiment. If many scientists get the same results, it helps supportthe hypothesis. A hypothesis that is supported by many differentinvestigations and observations becomes a theory.READING ESSENTIALSCopyright © by Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.What is a controlled experiment?NameDateClassSection1.2The Methods of Biology, continued◗ After You ReadMini Glossarycontrol: in an experiment, the standard againstwhich results are compareddata: information gathered from an experimentdependent variable: the condition in an experiment that results from the changes made tothe independent variableexperiment: an investigation that tests a hypothesis by collecting information under controlled conditionsindependent variable: in an experiment, thecondition that is tested because it affectsthe outcome of the experimentscientific methods: common steps that scientistsuse to do research and answer questionstheory: an explanation of a natural phenomenonor event that is supported by a large bodyof scientific evidence obtained from manydifferent investigations and observationshypothesis (hi PAHTH us sus): an explanation for aquestion or problem that can be tested1.
Review the terms and their definitions in the Mini Glossary above. Write a sentence using atleast two of the terms.________________________________________________________________________________________________________________________________________________________________________Copyright © by Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.2. Use the pyramid diagram to help you review what you have read. Arrange the steps used inscientific research in the order that they usually take place. Place the letter next to each stepin the right order in the pyramid.a. Conduct experiments4.b. Form a hypothesisc.
Observe and identify a problem to solve3.d. Study results data to see if hypothesis is supported2.1.3. Choose one of the question headings in the Read to Learn section. Write the question in thespace below. Then, write your answer to that question on the lines that follow.Question:Answer:________________________________________________________________________________________________________________________________________________________________________Visit the Glencoe Science Web site at science.glencoe.com to findyour book and learn more about the methods of biology.READING ESSENTIALSChapter 17NameDateClassSection1.3 The Nature of Biology◗ Before You ReadSC.H.2.4.2 The student knows that scientists control conditions in order to obtainevidence, but when that is not possible for practical or ethical reasons, they try toobserve a wide range of natural occurrences to discern patterns.
Also coversSC.H.1.4.1, SC.H.1.4.7, SC.H.2.4.1, SC.H.3.4.3, SC.H.3.4.2, SC.H.3.4.6In this section, you will learn how biologists use scientific research to study the natural world andmake important discoveries. Think of any important discoveries in the field of biology that youalready know about. Give as many examples as you can on the lines below.____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________◗ Read to LearnIn Your OwnWords Highlight the mainidea in each paragraph.
Stopafter every paragraph and putwhat you just read into yourown words.Scientific information can usually be broken down into twomain types—quantitative or qualitative. In quantitative research,results are compared by using numbers. Imagine an experimentto see when different materials begin to melt. The temperatureat which wax, iron, and glass each begins to melt is different.Temperatures often are measured in degrees, which are numberson a scale. These temperatures are a type of quantitative data inquantitative research.Qualitative research is based on observation.
It is also calleddescriptive research because it describes scientists’ observationswhen they do their research. If a scientist wanted to figure outhow a beaver builds a dam, numbers would not be very helpful.The scientist would observe the beaver and see how the dam isbuilt. Then the scientist would describe, in detail, all the steps thebeaver takes to build the dam.Science and Society1. What are the twomain types of scientificresearch?________________________________________________8Chapter 1Scientific research often provides society with important information. What we learn from scientific research cannot be definedas good or bad. Ethics must play a role in deciding how the information will be used.
Ethics are the moral principles and valuesheld by humans. Ethics are how we decide what is right or wrong,good or bad. Suppose scientists develop a new vaccine to cure adisease, but they can only produce 1000 doses each year. Ethicshelp society decide who should receive those doses. Society as awhole must take responsibility for making sure that scientific discoveries are used in an ethical way.READING ESSENTIALSCopyright © by Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.Kinds of InformationNameDateClassSection1.3The Nature of Biology, continuedSome scientific study is done only to learn new things.
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