Chapter 1:
The Science
of Biology
Marcellin Biology
What is SCIENCE?
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The goal of science is
1. Investigate and understand the natural world
2. Explain events in the natural world
3. Use explanations to make useful predictions
What is SCIENCE?
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Science is different because
1. Deals only with the natural world
2. Scientists collect and organize information in
a careful, orderly way. They look for patterns
and connections among events.
3.Scientists propose explanations that can be
tested by looking at evidence.
What is SCIENCE?
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An organized way of using evidence to learn
about the natural world.
What is SCIENCE?
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This “organized way” is also called …
THE SCIENTIFIC METHOD!
What is SCIENCE?
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Science is an ongoing process.
Good scientists must be skeptical. They must
constantly question existing ideas and new
hypotheses.
The Scientific Method
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1. Problem
2. Hypothesis
3. Procedure
Controlled Experiment
a. Manipulated (Independent) Variable
This is deliberately changed.
(ex. temperature, amount of light)
THERE IS ONLY 1 MANIPULATED VARIABLE
IN AN EXPERIMENT!!!!
The Scientific Method
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3. Procedure (continued)
b. Responding (Dependent) Variable
This changes in response to the manipulated
variable.
(ex. The height of a plant)
c. Control Group
Does not receive a variable
Used for comparison
The Scientific Method
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4. Data
5. Conclusion
6. Publish results
What happens if a hypothesis is wellsupported?
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It becomes a THEORY.
Theory- Well tested explanation that unifies a
broad range of observations.
A Controlled Experiment
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Hypothesis: What is the effect of environment
on a rabbit’s fur color?
We already know:
The rabbit normally has a white coat, except for
its nose, feet, tail, and ears which are black.
A Controlled Experiment
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Procedure:
1. Shave an area of hair on 2 rabbits.
2. Place an ice pack over the shaved area on one
rabbit (A).
Results:
Rabbit A developed a black patch of fur where
the ice pack was.
Rabbit B stayed the same.
A Controlled Experiment
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What can we conclude?
Cold temperatures changes the rabbit’s fur color
to black.
Which rabbit is the control group?
What is the manipulated variable? Responding?
Why do we need Rabbit B?