Reading Essentials for Biology Glencoe, страница 4

Anything in the environment—air, water, temperature, weather, other organisms—that causes theorganism to react is called a stimulus (plural, stimuli). The organism’s reaction to the stimulus is called a response. An organismalso has the ability to control its internal environment in orderto maintain conditions suitable for survival. For example, anorganism must make constant adjustments to maintain the rightamount of water and minerals in its cells. This ability is calledhomeostasis (hoh mee oh STAY sus). Without the ability to adjustto internal changes, an organism would die.3.

Name three or morethings that make up theenvironment.________________________________________________________________________________________________Copyright © by Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.How do organisms respond to change?Organisms use energy to grow, develop, respond to stimuli,and maintain homeostasis. Energy is the ability to cause change.Organisms get their energy from food.Any behavior, structure, or internal process that allows an organism to make changes in response to environmental factors and livelong enough to reproduce is called an adaptation (a dap TAY shun).For example, the leaves of many desert plants have a thick, waxycoating. This is an adaptation that helps these plants conservewater.

Having large eyes is an adaptation that lets owls see well atnight. The gradual change in a species over time due to adaptations is called evolution (e vuh LEW shun).4. Conclude Some treesdrop their leaves in thefall in response to: (Circleyour choice.)a. higher temperaturesb. lower temperaturesc. more daylight hours◗ After You ReadMini Glossaryadaptation (a dap TAY shun): any structure,behavior, or internal process that enables anorganism to respond to environmental factors and survive to produce offspringbiology: the study of life that seeks to providean understanding of the natural worlddevelopment: the changes that take place duringan organism’s life; one of the characteristicsof all living thingsenergy: the ability to cause changeenvironment: the surroundings to which anorganism must adjust; includes air, water,weather, temperature, organisms, andother factorsREADING ESSENTIALSevolution (e vuh LEW shun): gradual change in aspecies through adaptations over timegrowth: changes in an organism resulting in anincrease in the amount of living materialand the formation of new structures; one ofthe characteristics of all living thingshomeostasis (hoh mee oh STAY sus): an organism’s ability to control its internal environment to maintain conditions suitablefor survivalorganism: anything that possesses all the characteristics of lifeorganization: the orderly structure of cells in anorganism; one of the characteristics of allliving thingsChapter 13NameDateClassSection1.1What is biology?, continuedreproduction: the production of offspring; acharacteristic of all living thingsresponse: an organism’s reaction to a change inits environmentspecies (SPEE sheez): a group of organisms capable of mating with each other and producing offspring who can also reproducestimulus: anything in the environment thatcauses an organism to react1.

Review the terms and their definitions in the Mini Glossary above. Then on the lines below,write a sentence for each of the following words: adaptation, evolution, and homeostasis.____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________2.

Use the web diagram below to help you review what you have read about organisms. List thefour characteristics biologists use to recognize living things.3. Give two examples of ways in which humans depend on other living things.________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________Visit the Glencoe Science Web site at science.glencoe.com to findyour biology book and learn more about what biology is.4Chapter 1READING ESSENTIALSCopyright © by Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.Characteristicsof Living ThingsNameDateClassSection1.2 The Methods of Biology◗ Before You ReadSC.H.1.4.1 The student knows that investigations are conducted to explore new phenomena, to check on previous results, to test how well a theory predicts, and to compare different theories.

Also covers SC.G.1.4.1, SC.H.1.4.3, SC.H.2.4.1, SC.H.3.4.1, SC.H.1.4.7,SC.H.2.4.2, SC.H.3.4.3, SC.H.3.4.6Find the key terms hypothesis and experiment in the Read to Learn section below. Highlight andread the words and their definitions. Then, think of an experiment you might like to conduct. Onthe lines provided, explain the question you hope to answer with your experiment.______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________◗ Read to LearnObserving and HypothesizingCopyright © by Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.Even though biologists and other scientists study many different types of things, they all use the same basic steps.

The common steps they use to do research and answer questions are calledscientific methods. Scientists often figure out questions to askand answer just by observing the world around them.What is a hypothesis?Forming a hypothesis (hi PAHTH us sus) is a researchmethod scientists use often. A hypothesis is an explanation for aquestion or problem that can be tested. For example, imagine thatthe number of birds in an area decreased after snakes came intothe area.

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.