Transcript UPCO: Chapter 1-Biology and Scientific Inquiry

Scientific Inquiry
What is Science?
What is Science?
 A body of knowledge
 A set of theories that
describes the world
 A way of learning about the
world
 A method to answer
questions about the natural
world
How do Scientists Learn
About the World?
1.
2.
3.
4.
Ask a question
Make a prediction
Test the prediction
Compare results to the
prediction
5. Make a conclusion
6. Hypothesis is either rejected, or
supported
The Scientific Method-ask a question
 Only questions which can be
answered through experiments.
 Examples of good scientific
questions:
 How does the amount of nitrogen
fertilizer affect the height of pea
plants?
 Does increasing the temperature of
an enzyme increase its rate of
reaction?
Write a Good
Scientific Question.
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Scientific Method-make
a prediction
 Make a prediction
 A scientists prediction about the results of
an experiment is called the hypothesis
 The hypothesis must be testable and
specific and always written as a
statement
 Hypotheses usually begin with “I think
that……” or “If…………then…………”
 Example: I think that the more fertilizer
that a pea plant gets, the taller it will
grow
Scientific Method-test
the prediction
 Controlled Experiments
 Used by Scientists to test their
hypothesis
 Always have at least two groups:
 Control Group- stays the same
 Experimental Group- changes,
receives some sort of
treatment
How are the control group and the
experimental group different?
1.
2.
Scientific Methodcompare results
 Scientists analyze the data collected
 Data is information
 Compare the data from the control
group with the experimental group
 Use statistics to see if there is
significant difference
 Example- the pea plants in the
experimental group grew an average
of 18.3cm, while the control group
grew an average of 12.6cm
Scientific Method- make
a conclusion
 Examine data, charts,
graphs, to determine if the
hypothesis is supported or
rejected
 Could the differences be
due to chance?
 Use statistics to tell
Scientific Methodhypothesis rejected or
supported?
 If supported, repeat experiment
to see if it is valid ( able to be
repeated with the same results)
 If rejected, then come up with a
new hypothesis and experiment,
repeat the process
Controlled Experimentsvariables
 Three types of variables:
 Independent- the thing that is
different between the experimental
and control group
 Dependent- the data you collect
as your experiment progresses,
depends on the independent
variable
 Controlled- remains the same
I set up an experiment with 30 pea
plants. I give 10 plants no fertilizer, 10
plants 5g. of fertilizer, and 10 plants
15g. of fertilizer. After 14 days I
measure the height of the plants.
 What is the independent variable?
 The amount of fertilizer
 What is the dependent variable?
 The height of the pea plants
 What are the 2 controlled variables?
 The amount of soil and water
 What is the control group?
 Plants with no fertilizer
 What is the experimental group?
 The two groups of plants getting fertilizer
What makes a good
experiment?
 Large number of samples
 Only one independent
variable
 Validity
 Conclusions based on
evidence
 Is based on fact, not opinion
Design an Experiment !
 Think of an experiment to test the
hypothesis that sleeping more
than 8 hours a night improves a
students grades on Science
quizzes!
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Control group:
Experimental Group:
Independent Variable:
Dependent Variable:
Controlled Variables: