Text: Biology: The Study of Life

Biology

from the Greek words

bios, meaning “life,”

logos, meaning “study”;

Biology is the study of life.

• Through your study of biology, you will come to appreciate the great diversity of life on Earth and the way all living organisms fit into the dynamic pattern of life on our planet.

Biologists study the Diversity of LifeBiologists study the Diversity of Life

• Life on Earth includes not only

the common organisms you

notice every day, but also

distinctive life forms that have

unusual behaviors.

The Science of BiologyThe Science of Biology

• One of the most general principles in biology is that living

things do not exist in isolation; they are all functioning

parts in the delicate balance of nature.

• Biologists study the interactions of lifeBiologists study the interactions of life

Living things interact with their environment

and depend upon other living and nonliving

things to aid their survival

• the study of biology must include the

investigation of living interactions.

• The study of one living thing always

involves the study of the others with

which it interacts.

• The study of biology will teach you how humans function and how we fit in with the rest of the natural world.

• It will also equip you with the knowledge you need to help sustain this planet’s web of life.

Biologists study problems andpropose solutionsBiologists study problems andpropose solutions

• Biologists have formulated a list of characteristics by which we can recognize living things.

• Only when something has all of them can it then be considered living.

Characteristics of Living ThingsCharacteristics of Living Things

• Anything that possesses all of the characteristics of life is known as an organism.

Characteristics of Living ThingsCharacteristics of Living Things

All living things:

• have an orderly structure

• produce offspring

• grow and develop

• adjust to changes in the environment

Characteristics of Living ThingsCharacteristics of Living Things

• When biologists search for signs of life, one of the first things they look for is structure. That’s because they know that all living things show an orderly structure, or organization.

• Whether an organism is made up of one cell or billions of cells, all of its parts function together in an orderly, living system.

Living things are organizedLiving things are organized

How are living things like?• Any living thing is called an organism. • Organisms vary in size—from the microscopic

bacteria in mud puddles to gigantic oak trees— and are found just about everywhere

• One of the most obvious

of all the characteristics of

life is reproduction, the

production of offspring.

Living things make more living thingsLiving things make more living things• Reproduction is not essential

for the survival of an

individual organism, but it is

essential for the continuation

of the organism’s species.

Species

• A species is a group of

organisms that can

interbreed and produce

fertile offspring in

nature

• Horse

• Donkey

• Mule• sterile

Species? Fertile Offspring?

• Rama the cama shares the limelight with three

others of his species: conceived through

artificial insemination: llamas were inseminated

with camel semen.

• father lion + mother tiger = liger

father tiger + mother lion = tigon

• Liger’s, genetically, lean toward gigantism.

Tigon’s lean toward dwarfism.

Development-• Growth results in an increase in the

amount of living material and the

formation of new structures. All

organisms grow, with different parts of

the organism growing at different rates.

• All of the changes that take place during

the life of an organism are known as its

development

• Think about some of the structural

changes your body has already

undergone

since you were born.

• All life begins as a single cell.

• As cells multiply, each organism grows and

develops and begins to take on the

characteristics that identify it as a member of a

particular species.

• Moth metamorphosis- http://

www.youtube.com/watch?v=atOSro3_W7c

Living things change during their lives

Living Things Grow and Develop

• The length of time an organism is expected to live is its life span.

• Some organisms have a short life span, Others have a much longer life span.

• Some bristlecone pine trees have been alive for more than 4,600 years!

•

Living things adjust to their surroundings

• Organisms live in a constant

interface with their

surroundings, or environment,

which includes the air, water,

weather, temperature, any other

organisms in the area, and many

other factors.

• Stimulus- Anything in an

organism’s external or

internal environment that

causes the organism to react

• A reaction to a stimulus is a

response.

Living Things Respond to stimuli that occur

inside them. • Homeostasis is a trait of all living things.

• Regulation of an organism’s internal

environment to maintain conditions

suitable for its survival is called

homeostasis.

• Living things reproduce themselves,

grow and develop, respond to

external stimuli, and maintain

homeostasis by using energy.

• Homeostasis Thermoregulation Video

• http://wn.com/homeostasis?upload_time=all_time&orderby=published#/images

Energy is the ability to cause change.

• Living things reproduce themselves, grow and develop, respond to external stimuli, and maintain homeostasis by using energy.

• Organisms get their energy from food.

Plants make their own food, • Animals, fungi, and

other organisms get

their food from plants

or from organisms

that consume plants.

Living Things Use Energy

• The energy used by

most organisms comes

either directly or

indirectly from the Sun.

• Plants and some other

organisms use the Sun’s

energy, carbon dioxide,

and water to make food.

• Organisms that do not get

energy directly from the Sun

must take in oxygen in order to

release the energy in foods.

• You and most

other organisms

can’t use the

energy of sunlight

directly.

• Instead, you take

in and use food

as a source of

energy.

• Any structure, behavior, or internal process that enables an organism to respond to environmental factors and live to produce offspring is called an adaptation.

• Adaptations are inherited

• The gradual change in a species through adaptations over time is evolution.

Living things adapt and evolveLiving things adapt and evolve

Living things adjust to their surroundings

• Organisms live in a constant

• interface with their surroundings, or

environment.

• These include air, water, weather,

temperature, and any other organisms in

the area.

The fox responds to the presence of a rabbit by

quietly moving toward it, then pouncing.

Trees adjust to cold, dry winter weather by

losing their leaves. Trees that drop their

leaves in the fall conserve water and avoid

freezing during winter

What do living things need?

• To survive, all living things need a place to live and raw materials. The raw materials that they require and the exact place where they live can vary.

• All living things need a place to live, water, and food source to survive.

Question 1

How does society benefit from the study of biology?

Benefits include advances in medical treatments and disease prevention, learning more about how the human body functions, increasing knowledge of human relationships and better understanding of how to sustain the web of life on Earth.

Question 2

What is the origin of the term "biology"?

"Biology" comes from two Greek words, "bios" meaning life, and "logos" meaning study. Biology is the study of life.

Question 3

What are some characteristics of living things?

• All living things have an orderly structure

• produce offspring

• grow and develop

• and adjust to changes in the environment.

• Sometimes nonliving things have one or more of these characteristics, but unless something has all of them it is not considered to be a living thing.

These plants are called Lithops from the Greek lithos, meaning “stone.” Although they don’t appear to be so, Lithops are just as alive as elephants. Both species possess all of the characteristics of life.

Question 4A group of organisms that can interbreed and produce fertile offspring is a(n) __________.

D. niche

C. environment

B. species

A. organization

The answer is B, species.

Question 5

What is the importance of homeostasis?

Homeostasis is the regulation of an

organism's internal environment to

maintain conditions suitable for

survival.

An example is the adjustment an

organism makes in the amount of

water in its cells; without the ability

to make such adjustments, organisms

die.

Question 6Which of the following is an example of an adaptation?

D. all the changes that take place during

the lifetime of an organism

C. possessing large eyes for efficient night vision

B. changing only one condition at a time during an experiment

A. the gradual change in a species over time

The answer is C. A structure,

behavior or internal process that

enables an organism to respond to

environmental factors and live to

reproduce is an adaptation.

Evolution is the gradual change

of a species over time and occurs

through adaptations.

• Compare different scientific methods.

Section Objectives:

• Differentiate among hypothesis, theory, and principle.

Scientific HypothesisScience welcomes test to determine if a hypotheis is correct

• Testable explanation• May help establish a

theory• If it can’t be tested, it

isn’t based on science• Often leads to new

knowledge

• Many experiments can be done to support it and it is still a hypothesis

• If one experiment disproves it, it must be re-evaluated based on the new information.

• The new information must be considered and the hypothesis, law or principle must be changed to include the new knowledge gained

What if an experiment does not support a hypothesis?

• Glass is fragile• http://www.youtube.com/watch?v=6V2eCFsDkK

0

• http://www.youtube.com/watch?v=Pdy2_vi0FfM&feature=related

• A scientist must be prepared to change or abandon an idea.

• Feather Hammer Drop on Moon.click picture

• Ex. Aristotle believed heavy objects fell faster than lighter

NASA

A theory

• EXPLAINS how things function or occur

• a view that helps to explain many different phenomena

• A hypothesis that is supported by repeated experimentation

• All information supports the idea.

• Ex. Cell Theory• & Atomic Theory• Mermaid Theory- water

evolution? http://www.youtube.com/watch?v=GdGBcS0avAU&feature=related

Scientific Theories

• Must be refined based on new information as it becomes available

Atomic theory• 1. solid ball• 2. ball with electrons stuck

to outside• 3. electrons in fixed levels• 4. electron cloud

A law

• A law is a statement which is believed to be fact BUT offers no explanation

• Ex. Newton’s 3rd Law- For every action there is an equal and opposite reaction

Scientific Methods

• Scientific methods are used by scientists to answer

questions and solve problems.

• The development of the cell theory, illustrates how the

methods of science work.

• In 1665, Robert Hooke first observed cells in cork. He made

the drawing shown.

• The knowledge obtained when scientists answer one

question often generates other questions or proves useful in

solving other problems

• The common steps that biologists and other scientists use

to gather information and answer questions are collectively

known as scientific methods.

The methods biologists useThe methods biologists use

• Scientific methods usually begin with scientists

identifying a problem to solve by observing the world

around them.

Scientific Method

• 1. Recognize a problem

• 2. Form a Testable idea (hypothesis)

• 3. Predict consequences of a hypothesis

• 4. Perform experiments to test predictions

• 5. Formulate the simplest general rule that organizes the 3

main ingredients: Hypothesis, prediction, and

experimental outcomes

• A hypothesis is an explanation for a question • or a problem that can be formally tested. • A hypothesis is not a random guess • Eventually, the scientist may test a hypothesis by

conducting an experiment. • The results of the experiment will help the

scientist draw a conclusion about whether or not the hypothesis is correct.

The methods biologists useThe methods biologists use

• To a scientist, an

experiment is an

investigation that tests a

hypothesis by the process of

collecting

information under

controlled conditions.

ExperimentingExperimenting

What is a controlled experiment?What is a controlled experiment?

• Some experiments involve

two groups: the control

group and the

experimental group.

• The control is the group in

which all conditions are

kept the same.

• In a controlled experiment,

only one condition is

changed at a time.

• The experimental group is

the test group, in which all

conditions are kept the

same except for the single

condition being tested.

• The condition in an experiment that is changed is the

independent variable, because it is the only variable that

affects the outcome of the experiment

• While changing the independent variable, the scientist

observes or measures a second condition that results from

the change.

• This condition is the dependent variable, because any

changes in it depend on changes made to the independent

variable.

Designing an experimentDesigning an experiment

• Controlled experiments are most often used in laboratory settings.

Designing an experimentDesigning an experiment

• However, not all investigations are controlled.

• An investigation which has no control, may involve biological investigation, most often used in field work.

No control

• An investigation which has no control, is the

type of biological investigation most often used

in fieldwork.

• The design of the procedure that is selected

depends on what other investigators have done

and what information the biologist hopes to

gain.

• Sometimes, a biologist will design a second

investigation even while a first one is being

conducted, to answer the question.

In the future health care workers

may be able to GP software to

input and track the geographic

locations of patients who've

contracted deadly, communicable

diseases. Then, if an epidemic

pattern began to emerge, doctors

could go straight to the source

and administer antivirals or

vaccines before the killer gets

out of control.

Not all investigations are controlled.

• Suppose you were on a group of islands in the Pacific that is the only nesting

area for a large seabird known as a waved albatross.

• Watching the nesting birds, you observe that the female leaves the nest when

her mate flies back from a foraging trip.

• The birds take turns sitting on the eggs or caring for the chicks, often for two

weeks at a time.

• You might hypothesize that the birds fly around the island, or that they fly to

some distant location, in search of food.

• To test these hypotheses, you might attach a satellite transmitter to some of

the birds and record their travels.

• Information obtained

from investigations

• Often, data are in

numerical form.

Data gatheringData gatheringdata Quantitative data

• Numerical data may be measurements of time, temperature, length, mass, area, volume, or other factors.

• Numerical data may also be counts.

Qualitative Observation

• Sometimes data are expressed in verbal form, using

words to describe observations made during an

investigation.

• Scientists who first observed the behavior of pandas in

China obtained data by recording what these animals

do in their natural habitat and how they respond to

their environment.

• Learning that pandas are solitary animals with large

territories helped scientists understand how to provide

better care for them in zoos and research centers.

After careful review of the results, the scientist must come to a conclusion:

Thinking about what happenedThinking about what happened

• Was the hypothesis supported by the data?

• Was it not supported?

• Is more data needed?

Verifying results

• Data and conclusions are shared with other scientists for an important

reason.

• After results of an investigation have been published, other scientists can try

to verify the results by repeating the procedure. If they obtain similar results,

there is even more support for the hypothesis.

• Data from an investigation may be considered confirmed only if repeating

that investigation several times yields similar results.

• When a hypothesis is supported by data from additional investigations, it is

considered valid and is generally accepted by the scientific community.

• When a scientist publishes the results of his or her investigation, other

scientists can relate their own work to the published data.

AnalyzeThinking about what happened

• Often, the thinking that goes into analyzing data takes the greatest amount of a scientist’s time.

• After careful review of the results, the scientist must come to a conclusion:

• Was the hypothesis supported by the data? • Was it not supported? • Are more data needed?

After analyzing the data

Scientists often have more questions than they had before the investigation. They compare their results and conclusions with the results of other studies by researching the published literature for more information. They also begin to think of other experiments they might carry out.

Write an experiment

• Swirling milk• http://

www.youtube.com/watch?feature=endscreen&v=22r1zWOYiRM&NR=1

Common tools

Simple

• Beakers• test tubes• hot plates• petri dishes• Thermometers• Balances• metric rulers• graduated cylinders

Complex

• Microscopes• Centrifuges• radiation detectors• Spectrophotometers• DNA analyzers• gas chromatographs• Etc...

optical microscope

Gel electrophoresis can be used to produce a

DNA fingerprint as shown. Comparing DNA

reveals how closely related two species are

• Safety is another important factor that scientists consider when carrying out

investigations.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 when substances 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.

Maintaining safetyMaintaining safety

Main Ideas

• 1. Suppose you observed that bees prefer a yellow flower that produces more nectar over a purple flower that produces less nectar. List two separate hypotheses that you might make about bees and flowers.

• 2. Describe a controlled experiment you could perform to determine whether ants are more

• attracted to butter or to honey. • 3. What is the difference between a theory and a hypothesis? • 4. Why do some investigations require a control? • Thinking Critically • 5. Describe a way that a baker might conduct a controlled

experiment with a cookie recipe. • 6. Interpret Scientific Illustrations

What is the difference between a hypothesis and an observation?

Question 1

A hypothesis is an explanation for a question or problem and can be formally tested. An observation is something that has been noticed, often generating questions that lead to the formation of a hypothesis.

What is the independent variable in this experiment?

D. amount of water

C. plant height

B. amount of sunlight

A. soil volume

Question 2

The answer is B. The independent variable is the condition that is changed. In this case, the amount of sunlight is changed for each plant. Plant heights are measured results of the experiment, so plant height is the dependent variable.

Which of the following is the group in an experiment in which all conditions are kept the same?

Question 3

D. control

C. experimental

B. independent variable

A. standard

The answer is D. Conditions are kept the same in the control group. The experimental group is the test group.

Compare the terms "theory" and "principle".

Question 4

A theory is an explanation of a natural phenomenon that is supported by a large body of scientific evidence. A principle is a fact of nature, generally known to be true, such as the law of gravity.

• Compare and contrast quantitative and qualitative information.

Section Objectives:

• Explain why science and technology cannot solve all problems.

• Scientific information can usually be classified into one of two main types, quantitative or qualitative.

Kinds of Information

• Biologists sometimes conduct controlled experiments that result in counts or measurements—that is, numerical data.

Quantitative information

• These kinds of experiments occur in quantitative research. The data are analyzed by comparing numerical values.

• Quantitative data

may be used to

make a graph

or table.

Graphs and tables

communicate large

amounts of data in

a form that is easy

to understand

Quantitative information

Paramecium Survival Rates

Temperature

Nu

mb

er o

f p

aram

ecia

su

rviv

ing

Graphing

• Suppose, for example, that a biologist is studying the

effects of climate on freshwater life. He or she may

count the number of microscopic organisms, called

Paramecium, that survive at a given temperature.

This study is an example of quantitative research.

• Scientists always report measurements in a form of the metric system called the International System of Measurement, commonly known as SI.

Measuring in the International System

SI Base UnitsMeasurement Unit SymbolLength meter mMass kilogram kg

Time second sElectric current ampere ATemperature kelvin KAmount of substance mole molIntensity of light candela cd

Measuring in the International System In biology, the metric units you will encounter most often are:

• meter (length),

• gram (mass),• liter (volume),• second (time), and• Celsius degree (temperature).

• Observational data—that is, written descriptions of what

scientists observe—are often just as important in the

solution of a scientific problem as numerical data.

• When biologists use purely observational data, they are

using qualitative information.

Qualitative information

• Ethics refers to the moral principles and values

held by humans. Society as a whole must take

responsibility for the ethical use of scientific

discoveries.

• Scientists might not consider all the possible

applications for the products of their research

when planning their investigations.

• Society as a whole must take responsibility for the

ethical use of scientific discoveries.

Science and Society

Steps for Making Ethical Decisions

1.Identify the ethical issue or problem.

2.List the facts that have the most bearing on the decision.

3.Identify anyone who might be affected by your decision and how.

4.Explain what each affected person would want you to do about the

issue.

5. List three alternative actions and identify the best and worst case

scenario for each alternative, anyone who would be harmed by this

choice (and how), any values that would be compromised by selecting

this alternative, and any automatic reasons why this alternative

should not be selected (legal issues, rules, etc.).

6. Determine a course of action.

• Some questions are simply not in the realm of science.

Can science answer all questions?

• Such questions may involve decisions regarding good versus evil, ugly versus beautiful, or similar judgements.

Using DDT

Scientific Research

• Pure science- Scientific study

that is carried out mainly for

the sake of knowledge—with

no immediate interest in

applying the results to daily

living

• Applied Science- work in

research that has obvious and

immediate applications

• Pure Science that becomes applied

• water treatment plants,

• Vaccinations & antibiotics

• high-yielding crops

• brain scan

• are indirect results of research done

by scientists in many different fields

over hundreds of years.

Can technology solve all problems?

• Technology is the application of scientific research to

society’s needs and problems.

• Science and technology will

never answer all of the

questions we ask, nor will

they solve all of our

problems.

Technology

• has helped increase the production of

food, reduced the amount of manual

labor needed to make products and

raise crops, and aided in the reduction of

wastes and environmental pollution.

• The advance of technology has

benefited humans in numerous ways,

but it has also resulted in some serious

problems.

Key Concepts

• Biologists use controlled experiments to obtain data that either do or do not support a hypothesis. By publishing the results and conclusions of an experiment, a scientist allows others to try to verify the results. Repeated verification over time leads to the development of a theory.

• Scientific methods are used by scientists to answer questions or solve problems.

• Scientific methods include observing, making a hypothesis, collecting data, publishing results, forming a theory, developing new hypotheses, and revising the theory.

Explain the difference between quantitative and qualitative information.

Question 1

Quantitative information can be expressed

numerically, and may also be used to

generate graphs or tables in order to

communicate data clearly.

Qualitative information is not expressed

numerically.

Observational data and written

descriptions of what scientists observe, are

qualitative information.

U.S. Students Enrolledin Physical Education

MaleFemale

Why is the SI system important to scientists?

Question 2

SI is the International System of Measurement. The use of SI enables scientists anywhere in the world to understand data reported by other scientists, and makes peer review of results easier. SI Base Units

Measurement Unit SymbolLength meter mMass kilogram kg

Time second sElectric current ampere ATemperature kelvin KAmount of substance mole molIntensity of light candela cd

Which of the following is an SI unit?

Question 3

D. yard

C. second

B. pound

A. foot

The answer is C. Second is the SI unit of time.

SI Base UnitsMeasurement Unit SymbolLength meter mMass kilogram kg

Time second sElectric current ampere ATemperature kelvin KAmount of substance mole molIntensity of light candela cd

Explain how ethics are part of scientific discoveries.

Question 4

Ethics are a system of moral values or principles of right conduct. The knowledge gained through scientific research is not good or bad, but some applications of scientific knowledge may be considered unacceptable to some people. It is the responsibility of society as a whole to determine the ethical use of scientific discoveries.

How does technology benefit a society?

Question 5

Technology is the application of scientific research to society's needs and problems. It can result in improvements in such areas as food production, waste and pollution reduction, and medical care. While technology has provided numerous benefits, sometimes problems result as well.

• Biology is the organized study of living things and their interactions with their natural and physical environments.

• All living things have four characteristics in common: organization, reproduction, growth and development, and the ability to adjust to the environment.

What is biology?

• Biologists use controlled experiments to obtain data that either do or do not support a hypothesis. By publishing the results and conclusions of an experiment, a scientist allows others to try to verify the results. Repeated verification over time leads to the development of a theory.

The Methods of Biology

The Methods of Biology

• Scientific methods are used by scientists to answer questions or solve problems. Scientific methods include observing, making a hypothesis, collecting data, publishing results, forming a theory, developing new hypotheses, and revising the theory.

• Biologists do their work in laboratories and in the field. They collect both quantitative and qualitative data from their experiments and investigations.

• Scientists conduct investigations to increase knowledge about the natural world. Scientific results may help solve some problems, but not all.

The Nature of Biology

Question 1

What results in an increase in the amount of living material in an organism?

D. energy

C. stimuli

B. development

A. growth

The answer is A. Growth results in an increase of living material; development refers to the changes that take place during the life of the organism.

Question 2

Which of the following enables an organism to maintain homeostasis?

D. experimentation

C. energy

B. environment

A. evolution

The answer is C. Homeostasis is the regulation of an organism's internal environment. Living things maintain homeostasis, as well as grow and develop and reproduce themselves, by using energy from food.

Question 3

Compare the developments of unicellular and multi-cellular organisms.

Both types of organisms grow. However, multi-cellular organisms undergo more changes during their lives, therefore greater development, than do unicellular organisms.

Question 4

Compare the energy sources of plants and animals.

Organisms get their energy from food. Plants make their own food using energy from the Sun. Animals get their energy from plants or from organisms that consume plants.

Question 5Which of the following is an example of observational data? What type of data are the other examples?

D. average number of panda offspring per adult female

C. temperature at which bees cease flying

B. number of bees that visit a flower per day

A. description of panda behavior

The answer is A. The other examples are numerical data.

Question 6

Which of the following is an appropriate question for science to consider?

D. What birds prefer nesting in low shrubs?

C. Does breaking a mirror cause bad luck?

B. What brand of fertilizer should farmers use?

A. Which type of rose produces the most

pleasing scent?

The answer is D. Questions that involve judgments about beauty or matters of opinion are not in the realm of science.

Question 7

In a controlled experiment, the __________ is the observed condition that results from the change of the __________.

D. independent variable, hypothesis

C. dependent variable, control group

B. dependent variable, independent variable

A. independent variable, dependent variable

The answer is B. In a controlled experiment, the condition that is changed is the independent variable. The scientist then observes or measures the dependent variable that results.

Question 8

Define the term "evolution".

Evolution is the gradual change in a species through adaptations that are inherited from previous generations.

Camel EvolutionCamel EvolutionAge

Organism

Skull and teeth

Paleocene 65 million years ago

Eocene 54 million years ago

Oligocene 33 million years ago

Limb bones

Miocene 23 million years ago

Present

Question 9

Why are safety symbols important?

It is the responsibility of persons conducting scientific investigations to minimize hazards to themselves and others working around them. Safety symbols warn of any dangers that may exist.

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 when substances 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.

Question 10

Is technology always beneficial? Give examples to support your answer.

Technological advances have benefited humans

in numerous ways but have also resulted in

some serious problems. For example, fertilizer

that boosts crop production can also pollute

water. Value judgments must be made as to

how to utilize technology while protecting the

environment.

• Biology is the organized study of living things and their interactions with their natural and physical environments.

• All living things have four characteristics in common: organization, reproduction, growth and development, and the ability to adjust to the environment.

What is biology?

• Biologists use controlled experiments to obtain data that either do or do not support a hypothesis. By publishing the results and conclusions of an experiment, a scientist allows others to try to verify the results. Repeated verification over time leads to the development of a theory.

The Methods of Biology

The Methods of Biology

• Scientific methods are used by scientists to answer questions or solve problems. Scientific methods include observing, making a hypothesis, collecting data, publishing results, forming a theory, developing new hypotheses, and revising the theory.

• Biologists do their work in laboratories and in the field. They collect both quantitative and qualitative data from their experiments and investigations.

• Scientists conduct investigations to increase knowledge about the natural world. Scientific results may help solve some problems, but not all.

The Nature of Biology