Lab 1 – The Scientific Method and Termite Trails

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Welcome to NSB (Natural Science Biology)

• Why is Biology important?

– You encounter living things, and forces that act on living things every day

– Stem cells, cloning, DNA, genetic testing, vaccines, evolution, bioethics, animal and plant diversity, mutations, antibiotic resistance, viruses, diseases, global warming, energy, fossil fuels, genetically engineered foods.

– You want to be informed, so you can make smart choices for yourself, for your family, for your community, and for the world.

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Why do I need to take a lab?

• We want you to be able to “think like a scientist”• Labs provide a hands-on, active approach to

learning.• Labs demonstrate The Scientific Method.• Labs confirm that simple research can affect the

way you approach problems.• Lab fulfills the “science course with a lab”

requirement for general education

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Natural Science Syllabus Introduction

• Grading• Quizzes• Attendance• Participation• Paper/Presentation• Code of Conduct• Electronic Communications

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Lab Manual• Must be purchased for lab.

Available in Bookstore.• Needed every week to turn

in your questions. This is how you get your participation points.

• You must have your lab manual with you each lab, to have instructions for the lab. If you do not have your own set of instructions, you cannot participate in lab.

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In the lab - Lab Equipment• Always check to make sure you have all the

needed equipment before you begin your lab. • Lab equipment must always be stored properly

and cleaned to avoid contamination (Becoming nonsterile by contact with any nonsterile material). Never put away equipment that is dirty.

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In the lab - Safety Procedures1. Never conduct any

laboratory experiments until proper instructions have been given and a instructor is present.

2. If something goes wrong while performing a laboratory experiment, immediately get the attention of the instructor.

3. Always read the instructions and safety precautions before beginning an experiment.

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In the lab - Designing the Experiment

• Each of the lab has been designed to give you a “big picture” view of Biology.

• Each lab has the same format – a short lecture, background information, materials, the procedure, collecting data, and questions designed to assess your understanding.

• Each lab has a quiz over vocabulary and concepts• Each lab is conducted using “The Scientific

Method”

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The Scientific Method starts, stops, moves forward, moves backward, and rarely just

follows the circle.

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Much of what we do in science does not involve experiments

• Much of science is making observations and descriptions.– Different sizes– Different colors– Different structures– Different functions

– Then, we make predictions about why things might be different

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Forming a Hypothesis

• Forming a hypothesis first involves observation.

• Then, ask a question about something you observe. Your hypothesis will be a possible answer to that question.

• Remember a hypothesis does not have to be correct; it simply has to be testable.

• In fact, often hypotheses are wrong. However, even a wrong hypothesis is useful because it helps you rule out ideas.

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Examples of Hypotheses We Can Test

• More students get sick during the final week of testing that at other times.

• One solar panel can replace one C battery.• Disinfectants that contain bleach will kill 99% of E. coli bacteria

on hard surfaces.• Worker satisfaction increases worker productivity.• Amount of sun exposure will increase the growth of a tomato

plant.• Childhood obesity is tied to the amount of sugary drinks

ingested daily.• A dog can be trained to alert a human if the telephone is ringing.

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Testing a Hypothesis• You must design

a controlled experiment to test a hypothesis. A controlled experiment tests only one factor at a time.

• What would be included in the control, besides soil?

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Dependent v. Independent Variable

• Independent Variable – Changed– The one factor that you alter between experimental

groups

• Dependent Variable– Measured– Your result (data), (depends on what is changed)

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Data Collection Techniques• All of the information collected during a scientific

investigation is known as data. Data can be collected through the following techniques:

• Quantitative measurement – numerical (such as weight, volume, or how many legs)

• Qualitative observation – descriptive (such as colors, size, shape, feeling)

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Analyzing Data

• Data can be analyzed by making inferences from and recognizing patterns in the data. You might use the following methods to analyze your data:

– statistical analysis

– creating graphs

– organizing data into tables and charts

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Data Collection and Sample Size

• The larger the amount of data collected,

• The larger the sample size,

• The more times the experiment is repeated,

• The more valid the results.

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Collect and Interpret Data• When you collect data you need to be

concerned about precision and accuracy.

• Precision in Data Collection– Precision refers to how consistent and

reproducible a measurement is. A good rule of thumb is to take measurements two or three times (called replicates) in order to ensure precision

• Accuracy in Data Collection– Accuracy refers to the correctness of a

measurement. Data will be useless unless it is collected accurately.

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Precision vs. Accuracy

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All the measurements are close together

All the measurements are close to center

• Which piece of equipment would be best for accurately measuring 76 ml?

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Do I have a theory, or do I have a hypothesis?

• Scientists use the word “theory” differently than the general public. A theory in science is not a guess.

• A scientific theory is a set of principles that explain and predict phenomena, after repeated observations and experiments.

• Once a hypothesis is verified, it becomes a theory.• Examples of scientific theories – cell theory,

evolutionary theory, big bang theory, theory of relativity

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What’s YOUR hypothesis?

• The termites used in this experiment are a group of social insects usually classified at the taxonomic rank of order Isoptera. As truly social animals, they are termed eusocial .

• Eusocial animals display several characteristics – they have a queen, workers or laborers, defenders, colonies, castes – but why?

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How to “do” the lab

• Read the background information• Look at your materials and procedure – what

are you going to do, and why?• Follow directions, and fill in your data sheet for

Lab 1.• Make sure your full, real name, section, and TA

are on the handout, and turn it in.• You aren’t finished until your lab station is clean

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