Chapter 1:Chapter 1: The Study of Life The Study of Life

Biology, Fournier, McGraw, Biology, Fournier, McGraw, Reissfelder, LanceReissfelder, Lance

1.1 Introduction to Biology1.1 Introduction to Biology

Objectives:Objectives: Define biologyDefine biology Identify possible benefits from Identify possible benefits from

studying biologystudying biology Summarize the characteristics of Summarize the characteristics of

living thingsliving thingsMain idea:Main idea: All living things share the characteristics of All living things share the characteristics of

lifelife

BiologyBiology

The science of lifeThe science of life When people study living things or When people study living things or

pose questions about the pose questions about the environment, they are learning about environment, they are learning about biologybiology

Life flourishes on Earth, and a curiosity Life flourishes on Earth, and a curiosity about life is a major reason why some about life is a major reason why some people study biology people study biology

BiologistBiologist

The people who study biologyThe people who study biology They study the structure and function They study the structure and function

of living things, their history, of living things, their history, interactions among environments, and interactions among environments, and many other aspects of life.many other aspects of life.

What do Biologists do?What do Biologists do?

They make discoveries and see explanations They make discoveries and see explanations by performing laboratory and field by performing laboratory and field investigationsinvestigations– Study the diversity of lifeStudy the diversity of life– Research diseaseResearch disease– Develop technologiesDevelop technologies

Technology-the application of scientific knowledge to Technology-the application of scientific knowledge to solve human needs and to extend human capabilitiessolve human needs and to extend human capabilities

– Improve agricultureImprove agriculture– Preserve the environmentPreserve the environment

The Characteristics of LifeThe Characteristics of Life

Biologists concluded that all living things have Biologists concluded that all living things have certain characteristics. An certain characteristics. An organismorganism is anything is anything that has or once had all the characteristics of life.that has or once had all the characteristics of life.

Characteristics of Living OrganismsCharacteristics of Living Organisms– Made of one or more cellsMade of one or more cells– Displays organizationDisplays organization– Grows and developsGrows and develops– ReproducesReproduces– Responds to stimuliResponds to stimuli– Requires energyRequires energy– Maintains homeostasisMaintains homeostasis– Adaptations evolve over timeAdaptations evolve over time

Made of one or more cellsMade of one or more cells

All organisms are made of one or more All organisms are made of one or more cellscells

The The cellcell is the basic unit of life is the basic unit of life A bacterium is A bacterium is unicellularunicellular – it has just – it has just

one cellone cell Humans and plants are Humans and plants are multicellularmulticellular – –

they have many cells they have many cells

Displays organizationDisplays organization

The levels of The levels of organization organization (arranged in (arranged in an orderly way) in biological systems an orderly way) in biological systems begin with atoms and molecules and begin with atoms and molecules and increase in complexityincrease in complexity

Each organized structure in an Each organized structure in an organism has a specific functionorganism has a specific function– Specialized cells – Tissues – Organs - Specialized cells – Tissues – Organs -

Organ System - OrganismOrgan System - Organism

Grows and developsGrows and develops

GrowthGrowth results in an increase in mass results in an increase in mass in an organism, and in many in an organism, and in many organisms, the formation of new cells organisms, the formation of new cells and new structuresand new structures

DevelopmentDevelopment results in different results in different abilities. It is the process of natural abilities. It is the process of natural changes that take place during the life changes that take place during the life of an organismof an organism

ReproducesReproduces

Organisms Organisms reproducereproduce – produce – produce offspring and pass along traits from one offspring and pass along traits from one generation to the nextgeneration to the next

If a species is to continue to exist, then If a species is to continue to exist, then members of that species must members of that species must reproducereproduce

SpeciesSpecies – a group of organisms that can – a group of organisms that can breed with one another and produce breed with one another and produce fertile offspringfertile offspring

Responds to stimuliResponds to stimuli An organism’s An organism’s external external

environmentenvironment includes all things includes all things that surrounds it, such as air, that surrounds it, such as air, water, soil, rocks, and other water, soil, rocks, and other organisms.organisms.

An organism’s An organism’s internal internal environmentenvironment is all things inside is all things inside itit

A A stimulusstimulus (plural, stimuli) is (plural, stimuli) is anything that is part of either anything that is part of either environment and causes some environment and causes some sort of reaction by the organismsort of reaction by the organism

A A responseresponse is the reaction to is the reaction to stimulus stimulus

Being able to respond to the Being able to respond to the environment is critical for an environment is critical for an organism’s safety and survivalorganism’s safety and survival

Requires energyRequires energy

Energy is required for all life processesEnergy is required for all life processes Living things need sources of energy Living things need sources of energy

to fuel their life functionsto fuel their life functions Examples include:Examples include:

– Light energy from the Sun to make foodLight energy from the Sun to make food– Energy obtained by consuming other Energy obtained by consuming other

organismsorganisms

Maintains homeostasisMaintains homeostasis

All organisms keep internal conditions All organisms keep internal conditions stable by a process called homeostasisstable by a process called homeostasis

HomeostasisHomeostasis is the regulation of an is the regulation of an organism’s internal conditions to organism’s internal conditions to maintain life.maintain life.

Example – Humans perspire to prevent Example – Humans perspire to prevent their body temperature from rising too their body temperature from rising too high.high.

Adaptations evolve over timeAdaptations evolve over time

Adaptations are inherited Adaptations are inherited characteristics that result from characteristics that result from changes to a species over time.changes to a species over time.

IntroductionIntroduction to Biology to Biology

1.1. Describe four characteristics used to Describe four characteristics used to identify whether something is alive.identify whether something is alive.

2.2. Explain why cells are considered the Explain why cells are considered the basic unit of living things.basic unit of living things.

3.3. List some of the benefits of studying List some of the benefits of studying biology.biology.

4.4. Differentiate between response and Differentiate between response and adaptationadaptation

1.2 The Nature of 1.2 The Nature of ScienceScience

Objectives:Objectives:Explain the characteristics of scienceExplain the characteristics of scienceCompare something that is scientific Compare something that is scientific with something that is pseudosciencewith something that is pseudoscienceDescribe the importance of the metric Describe the importance of the metric system and SIsystem and SIMain idea:Main idea:Science is a process based on inquiry Science is a process based on inquiry that seeks to develop explanationsthat seeks to develop explanations

What is science?What is science?

ScienceScience is a body of knowledge based is a body of knowledge based on the study of nature and its physical on the study of nature and its physical setting.setting.

The nature, or central purpose, of The nature, or central purpose, of science is scientific inquiry – the science is scientific inquiry – the development of explanationsdevelopment of explanations

Scientific inquiryScientific inquiry is both a creative is both a creative process and a process rooted in process and a process rooted in unbiased observations and unbiased observations and experimentationexperimentation

What is science? (cont.)What is science? (cont.)

Uses scientific theoryUses scientific theory Expands scientific knowledgeExpands scientific knowledge Challenges accepted theoriesChallenges accepted theories Questions resultsQuestions results Tests claimsTests claims Undergoes peer reviewUndergoes peer review

Uses scientific theoryUses scientific theory

When enough evidence from many related When enough evidence from many related investigations supports an idea, scientists investigations supports an idea, scientists consider that idea a theory.consider that idea a theory.

TheoryTheory – an explanation of a natural – an explanation of a natural phenomenon supported by many phenomenon supported by many observations and experiments over timeobservations and experiments over time

Examples of Biological Theories – cell theory Examples of Biological Theories – cell theory and theory of evolution.and theory of evolution.– Based on countless observations and Based on countless observations and

investigationsinvestigations– Have extensive supporting evidenceHave extensive supporting evidence– Enable biologists to make accurate predictionsEnable biologists to make accurate predictions

Expands scientific knowledgeExpands scientific knowledge

Most scientific fields are guided by Most scientific fields are guided by research in a constant reevaluation of research in a constant reevaluation of what is knownwhat is known

This reevaluation often leads to new This reevaluation often leads to new knowledge that scientists then evaluateknowledge that scientists then evaluate

The search for new knowledge is the The search for new knowledge is the driving force that moves science driving force that moves science forwardforward

Expands scientific knowledge Expands scientific knowledge (cont.)(cont.)

Nearly every new finding causes Nearly every new finding causes scientists to ask more questions that scientists to ask more questions that require additional research. Examples require additional research. Examples include Milestones in Biology on p. 12include Milestones in Biology on p. 12

With pseudoscience, little research is With pseudoscience, little research is donedone

Pseudoscientific ideas generally do not Pseudoscientific ideas generally do not ask new questions or welcome more ask new questions or welcome more researchresearch

Challenges accepted theoriesChallenges accepted theories

Scientists welcome debate about one Scientists welcome debate about one another’s ideasanother’s ideas

Often, disagreements occur among Often, disagreements occur among scientistsscientists

Then additional investigations and/or Then additional investigations and/or experiments are done to substantiate experiments are done to substantiate claimsclaims

Sciences advance by accommodating Sciences advance by accommodating new information as it is discoverednew information as it is discovered

Questions resultsQuestions results Observations or data that are not consistent with Observations or data that are not consistent with

current scientific understanding are of interest to current scientific understanding are of interest to scientistsscientists

These inconsistencies often lead to further These inconsistencies often lead to further investigationsinvestigations

With pseudoscience, observations or data that are With pseudoscience, observations or data that are not consistent with beliefs are discarded or ignorednot consistent with beliefs are discarded or ignored

Tests claimsTests claims

Science-based information makes claims Science-based information makes claims based on a large amount of data and based on a large amount of data and observations obtained from unbiased and observations obtained from unbiased and carefully controlled investigations and carefully controlled investigations and experimentationexperimentation

Conclusions are reached from evidenceConclusions are reached from evidence Pseudoscience often makes claims that Pseudoscience often makes claims that

cannot be testedcannot be tested These claims often are a mixture of fact and These claims often are a mixture of fact and

opinionopinion

Undergoes peer reviewUndergoes peer review

Science-based information is made public and Science-based information is made public and reviewed by scientists’ peers – scientists who reviewed by scientists’ peers – scientists who are working in the same field of studyare working in the same field of study

Peer reviewPeer review – is a process by which, in – is a process by which, in science, the procedures used during an science, the procedures used during an experiment and the results are evaluated by experiment and the results are evaluated by scientists who are in the same field or scientists who are in the same field or conducting similar research.conducting similar research.

Scientists can repeat the work of others as Scientists can repeat the work of others as part of a new experimentpart of a new experiment

MeasurementsMeasurements

Scientists use the same system of measurements to Scientists use the same system of measurements to repeat experimentsrepeat experiments

The metric system is generally used by scientists The metric system is generally used by scientists when collecting data and conducting experimentswhen collecting data and conducting experiments

The metric system uses units with divisions that are The metric system uses units with divisions that are powers of tenpowers of ten

The system is called the International Systems of The system is called the International Systems of Units known as SIUnits known as SI

The SI units you will use most often are meter (to The SI units you will use most often are meter (to measure length), gram (to measure mass), liter (to measure length), gram (to measure mass), liter (to measure volume) and second (to measure time).measure volume) and second (to measure time).

Science in Everyday LifeScience in Everyday Life

In order to evaluate the vast amount of information In order to evaluate the vast amount of information available in print, online, and on television, and to available in print, online, and on television, and to participate in the fast-paced world of the 21participate in the fast-paced world of the 21stst Century. Each of us must be science literate.Century. Each of us must be science literate.

A person who is science literate combines a basic A person who is science literate combines a basic understanding of science and its processes with understanding of science and its processes with reasoning and thinking skillsreasoning and thinking skills

Many of the issues that are faced every day relate Many of the issues that are faced every day relate to the world of biology and involve ethics.to the world of biology and involve ethics.

EthicsEthics are a set of moral principles or values are a set of moral principles or values Ethical issues must be addressed by society based Ethical issues must be addressed by society based

on values it holds importanton values it holds important

1.3 Methods of Science1.3 Methods of Science

Objectives:Objectives:Describe the difference between an Describe the difference between an observation and an inferenceobservation and an inferenceDifferentiate among control, Differentiate among control, independent variable, and independent variable, and dependent variable.dependent variable.Identify the scientific methods a Identify the scientific methods a biologists uses for researchbiologists uses for research

Ask a QuestionAsk a Question

Scientific inquiry begins with observationScientific inquiry begins with observation ObservationObservation is a direct method of gathering is a direct method of gathering

information in an orderly wayinformation in an orderly way Scientific inquiry involves asking questions Scientific inquiry involves asking questions

and processing information from a variety of and processing information from a variety of reliable sourcesreliable sources

After observing, you might combine what After observing, you might combine what you know with what you have learned and you know with what you have learned and begin a process of making logical begin a process of making logical conclusions called conclusions called inferencesinferences, or inferring., or inferring.

Scientific methodsScientific methods

Biologists use similar methods to Biologists use similar methods to gather information and answer gather information and answer questionsquestions

Even though scientists do not perform Even though scientists do not perform scientific methods in the same way scientific methods in the same way each time they conduct an each time they conduct an experiment, observing and inferring experiment, observing and inferring happen throughout the entire processhappen throughout the entire process

Scientific Method (cont.)Scientific Method (cont.) A problem-solving tool used by scientists to A problem-solving tool used by scientists to

determine the validity of a determine the validity of a hypothesishypothesis. . It is an organized process for finding a It is an organized process for finding a

solution to a solution to a questionquestion.. Typical eight steps:Typical eight steps:

1.1.State the State the problemproblem2.2.Make Make observationsobservations & gather information & gather information3.3.Form a Form a hypothesishypothesis4.4.Write down the Write down the procedures procedures that will be used to that will be used to

test your test your experimentexperiment5.5.Perform an Perform an experimentexperiment to test the to test the hypothesishypothesis6.6.ObserveObserve, collect and , collect and recordrecord data. data.7.7.InterpretInterpret your results and data. your results and data.8.8.Form a Form a conclusionconclusion

Step 1Step 1

1.1. State the problem in a form of a State the problem in a form of a question.question.• Question Question – the inquiry or problem relating to a – the inquiry or problem relating to a

topic that can be answered by conducting an topic that can be answered by conducting an experimentexperiment

• What is it that you are trying to accomplish with What is it that you are trying to accomplish with your observations and measurements?your observations and measurements?

• It is extremely important to begin with a solid It is extremely important to begin with a solid problem or question.problem or question.

• A good question can be examined, measured A good question can be examined, measured and analyzed.and analyzed.

• Choose a problem that you do not know the Choose a problem that you do not know the answer to and a problem that you can work with.answer to and a problem that you can work with.

Step 2Step 22.2. Make observations & gather information about Make observations & gather information about

what you are studying – what you are studying – researchresearch the problem. the problem. Research Research – to conduct an investigation into current – to conduct an investigation into current

information about something.information about something. Research can either make or break the project.Research can either make or break the project. When doing research, use a wide variety of resources When doing research, use a wide variety of resources

outside of the school library.outside of the school library. Research resources: books, library index, newspapers, Research resources: books, library index, newspapers,

magazines, science videos, and internet.magazines, science videos, and internet. Scientists rely heavily on the scientific method because Scientists rely heavily on the scientific method because

there are so many there are so many variablesvariables to consider and any one of to consider and any one of them can affect the results of the experiment.them can affect the results of the experiment.– Variables Variables – something that can change or influence the results – something that can change or influence the results

of an experiment.of an experiment.

Step 3Step 33.3. Form a Form a hypothesishypothesis Hypothesis Hypothesis – a reasonable assumption based on – a reasonable assumption based on

research about a possible solution or answer to your research about a possible solution or answer to your problem or question.problem or question.

Developing a good, solid hypothesis is the most Developing a good, solid hypothesis is the most difficult step of the scientific method.difficult step of the scientific method.

Your hypothesis is the center of your project.Your hypothesis is the center of your project. The hypothesis will be stated as an if, then, The hypothesis will be stated as an if, then,

because statement. It is a testable explanation because statement. It is a testable explanation of a situation.of a situation.

If the hypothesis doesn’t make sense, the whole If the hypothesis doesn’t make sense, the whole project won’t make sense.project won’t make sense.

When forming the hypothesis, stick with a simple When forming the hypothesis, stick with a simple statement, and make it precise and measurable.statement, and make it precise and measurable.

Step 4Step 44. Write down the 4. Write down the proceduresprocedures that will be that will be

used to used to test your experiment.test your experiment. Procedure Procedure – a sequence of steps involved – a sequence of steps involved

in performing an experiment.in performing an experiment. Detailing the entire experiment and Detailing the entire experiment and

recording analyzed, scientists are able to recording analyzed, scientists are able to track the validity of the hypothesis.track the validity of the hypothesis.

Writing your procedure will:Writing your procedure will:– Help one gather the necessary materialsHelp one gather the necessary materials– Make sure that the experiment fits the Make sure that the experiment fits the

hypothesis that is being testedhypothesis that is being tested– Help others who want to repeat the experimentHelp others who want to repeat the experiment

Step 5Step 55.5. Perform the experiment by following the Perform the experiment by following the

procedure to test the hypothesis.procedure to test the hypothesis. Groups Groups – conditions– conditions

– Control group – Control group – are not variables being tested ; remain are not variables being tested ; remain normalnormal

– Experimental group – Experimental group – the group that is being tested by the group that is being tested by changing one variable at a timechanging one variable at a time

VariablesVariables – the factors that are being tested in – the factors that are being tested in the experiment. It is critical that everything in the the experiment. It is critical that everything in the experiment is the same each time it is tested, experiment is the same each time it is tested, except for the one variable that is being tested.except for the one variable that is being tested.

– Independent variable Independent variable – the one thing that separates – the one thing that separates the two groups; the tested factorthe two groups; the tested factor

– Dependent variableDependent variable – the data obtained from the – the data obtained from the experiment; it results from or depends on changes to the experiment; it results from or depends on changes to the independent variableindependent variable

Constant-Constant-a factor that remains fixed during an a factor that remains fixed during an experiment experiment

Step 6Step 6

6. 6. Observe, collect and Observe, collect and record record datadata Record Record – to write accurate information about what – to write accurate information about what

occurs during an experiment.occurs during an experiment. While performing an experiment:While performing an experiment:

– You may see changes in color, size, texture, odor, weight, You may see changes in color, size, texture, odor, weight, movement, shape, etc.movement, shape, etc.

– Always observe and record the dataAlways observe and record the data– Data may be quantitative (#) or qualitative (descriptions)Data may be quantitative (#) or qualitative (descriptions)– Watch your experiment closely and note any reactions that Watch your experiment closely and note any reactions that

occuroccur– Keep results together in one journal or lab bookKeep results together in one journal or lab book– Data may be generated using graphs, charts, and tablesData may be generated using graphs, charts, and tables– Be Be ethical ethical and honest about the data from the experimentand honest about the data from the experiment

Ethical Ethical – following the rules of being fair and honest– following the rules of being fair and honest

Step 7Step 77. Interpret7. Interpret your data your data

and resultsand results Interpret Interpret – to explain – to explain

or give meaning toor give meaning to When interpreting the When interpreting the

data, make sure to:data, make sure to:– Make tables, charts and Make tables, charts and

graphsgraphs– Draw pictures or take Draw pictures or take

photographs to show the photographs to show the procedure and results procedure and results

– Write a summaryWrite a summary

Step 8Step 88. 8. Form a Form a conclusion conclusion as to whether the data as to whether the data

you collected supports your hypothesis, then you collected supports your hypothesis, then you can say that your hypothesis is reliable. you can say that your hypothesis is reliable.

Conclusion – Conclusion – the result or outcome of the result or outcome of somethingsomething

If the data did not support your hypothesis, If the data did not support your hypothesis, then you would have to make new then you would have to make new observations and state a new hypothesis. observations and state a new hypothesis. Make sure that it is one you can test.Make sure that it is one you can test.

In your conclusion, state:In your conclusion, state:– What happened in your experiment?What happened in your experiment?– Was it what you expected? Was it what you expected? – Did your results agree with the hypothesis?Did your results agree with the hypothesis?– Did the experiment answer your original Did the experiment answer your original

question?question?

Biology Research:Biology Research:An idea to a published articleAn idea to a published article

An idea or question forms a hypothesisAn idea or question forms a hypothesis An experiment tests the hypothesisAn experiment tests the hypothesis Data is analyzed from the experiment Data is analyzed from the experiment The analysis and conclusions are The analysis and conclusions are

reported and published reported and published

SerendipitySerendipity

The occurrence of accidental or The occurrence of accidental or unexpected but fortunate results.unexpected but fortunate results.

Example: penicillinExample: penicillin

Lab SafetyLab Safety

Safety symbol is a logo designed to Safety symbol is a logo designed to alert you about a specific dangeralert you about a specific danger

Fill in the blanksFill in the blanksThe (1)______ method is one way that people think about and solveThe (1)______ method is one way that people think about and solvequestions or problems. When you begin your experiment, it is questions or problems. When you begin your experiment, it is

importantimportantto state a problem or (2)_____ that you would like to find an answer to.to state a problem or (2)_____ that you would like to find an answer to.It is important to look up or (3) _____ up-to-date information about yourIt is important to look up or (3) _____ up-to-date information about yourtopic before you conduct any experiments. A(n) (4)_____ is a possibletopic before you conduct any experiments. A(n) (4)_____ is a possibleexplanation about something. To conduct a(n) (5)_____ is a good wayexplanation about something. To conduct a(n) (5)_____ is a good wayto discover something new about science. Be sure to write down eachto discover something new about science. Be sure to write down eachstep or (6)_____ in the correct order before you start your sciencestep or (6)_____ in the correct order before you start your scienceexperiment. When you conduct an experiment and you deliberatelyexperiment. When you conduct an experiment and you deliberatelychange one thing, you are introducing a(n) (7)_____. It is critical to change one thing, you are introducing a(n) (7)_____. It is critical to watch or (8)_____ what is happening with every step of yourwatch or (8)_____ what is happening with every step of yourexperiment. After you conduct your experiment, a valuable step is toexperiment. After you conduct your experiment, a valuable step is towrite down or (9)_____ what happened. When you explain whatwrite down or (9)_____ what happened. When you explain whathappened in your experiment, you (10)_____ the results. Sharing truehappened in your experiment, you (10)_____ the results. Sharing trueinformation about the outcome of your experiment is an example ofinformation about the outcome of your experiment is an example of(11)_____ behavior. After an experiment, it is important to write down(11)_____ behavior. After an experiment, it is important to write downyour (12) _____ or summary of what you learned.your (12) _____ or summary of what you learned.