Lab 1 – the scientific method and termite trails fall 2014
1. Lab 1 – The Scientific Method
and Termite Trails
#NSB2014 1
2. 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.
#NSB2014 2
3. 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
#NSB2014 3
5. 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.
#NSB2014 5
6. 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.
#NSB2014 6
7. In the lab - Safety Procedures
1. 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.
#NSB2014 7
8. 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”
#NSB2014 8
9. The Scientific Method starts, stops,
moves forward, moves backward, and
rarely just follows the circle.
#NSB2014 9
10. 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
#NSB2014 10
11. 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.
#NSB2014 11
12. 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.
#NSB2014 12
13. 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?
#NSB2014 13
14. 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)
#NSB2014 14
15. 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)
#NSB2014 15
16. 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
#NSB2014 16
17. 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.
#NSB2014 17
18. 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.
#NSB2014 18
19. Precision vs. Accuracy
#NSB2014 19
All the measurements are
close together
All the measurements are
close to center
20. • Which piece of
equipment would be
best for accurately
measuring 76 ml?
#NSB2014 20
21. 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
#NSB2014 21
22. 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?
#NSB2014 22
23. 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 and ready for the next class.
#NSB2014 23