The Nature of Science and Controlled Experiment – Notes
The ______________________of science is to investigate and understand
__________________, to explain events in nature, and to use those explanations
to make useful _____________________________________.
I. What is science?
A. Science is an organized way of using ___________________________
to learn about the ___________________________ world.
B. It also means the body of_____________________ that exists about the
natural world
–Science only deals with what can be __________________. It does not make
value judgments.
II. What skills are necessary in order to be a good scientist?
1._____________________
2.Honesty
3.Open-mindedness
4._________________________________
5.Logical thinking
6.Patience
7.___________________________________________________________!
III. The Significance of Biology as a Science
1.The world’s __________________________ supply
2.Environmental factors that might be harmful
3.Maintaining the __________________________________
4.Medicines and medical treatment
5.Maintaining good ____________________________________
6.Providing __________________ to power automobiles, homes, and industry
--An understanding of science and the scientific approach is essential to making
__________________________________________decisions.
Designing an Experiment using the Steps of Scientific Method - a series of steps
scientists use to answer or solve a problem
1. State the ___________________________
2. Form a Hypothesis
3. Set Up a Controlled ___________________________________
4. Record Results
5. Analyze ______________________________
6. Draw a Conclusion
7. __________________________________Results
8. ______________!!
A Controlled Experiment – Notes
Tim and
Moby’s
Experiment
Name:_____________
Why did Tim and Moby want to set up an experiment?
What were they testing?
Throughout the experiment, what did each plant have or receive that was exactly the
same?
Throughout the experiment, what did each plant receive that was varied or different?
Controlled
Experiment
A. A Controlled Experiment only tests ______________ manipulated variable at a time
(Variable= factor in a controlled _______________________that can change)
B._______________ – sometimes called constants, what the scientist keeps constant
o Most experiments have a control group. This group does not receive the
manipulated variable. The control group is used as a standard of
comparison. Tim and Moby’s control variables:
C.____________________ Variable- sometimes called the independent variable, what
the scientist deliberately changes (Should only have one – this is usually what is being
tested) Tim and Moby’s manipulated variable:
D.______________________ Variable – sometimes called the dependent variable,
changes in response to the manipulated variable and is usually what you measure to
gather data Tim and Moby’s responding variable:
Controlled
Experiment:
Spontaneous
Generation
a Historical
Example
OBSERVATIONS: Flies land on meat that is left uncovered. Later, maggots
appear on meat.
HYPOTHESIS:
Controls:
Manipulated Variable (independent):
Responding Variable (dependent):
CONCLUSION:
Experiments ________________: a possible explanation or answer to a scientific question;
allow a
experiments are performed to test a hypothesis
hypothesis
to become a
theory.
___________________: a hypothesis that has been supported by many
experiments
Scientific Method In Action
The Strange Case of Beriberi
In 1887 a strange nerve disease attacked the people in the Dutch East Indies. The disease was beriberi.
Symptoms of the disease included weakness and loss of appetite, Victims often died of heart failure.
Scientists thought the disease might be caused by bacteria. They injected chickens with bacteria from the
blood of patients with beriberi. The injected chickens became sick. However, so did a group of chickens that
were not injected with bacteria from the blood from the patients with berberi.
One of the scientists, Dr. Eijkman, noticed something. Before the experiment, all the chickens had eaten
whole-grain rice, but during the experiment, the chickens were fed polished rice. Dr. Eijkman researched
this interesting case. He found that polished rice lacked thiamine, a vitamin necessary for good health.
1. State the Problem
2. What was the hypothesis?
3. How was the hypothesis tested?
4. Should the hypothesis be supported or rejected based on the experiment?
5. What should be the new hypothesis?
How Penicillin Was Discovered
In 1928, Sir Alexander Fleming was studying Staphylococcus bacteria growing in culture dishes. He noticed
that a mold called Penicillium was also growing in some of the dishes. A clear area existed around the mold
because all the bacteria that had grown in this area had died. In the culture dishes without the mold, no
clear areas were present.
Fleming hypothesized that the mold must be producing a chemical that killed the bacteria. He decided to
isolate this substance and test it to see if it would kill bacteria. Fleming transferred the mold to a nutrient
broth solution. This solution contained all the materials the mold needed to grow. After the mold grew, he
removed it from the nutrient broth. Fleming then added the nutrient broth in which the mold had grown to a
culture of bacteria. He observed that the bacteria died.
6. Identify the problem.
7. What was Fleming's hypothesis?
8. How was the hypothesis tested?
9. Should the hypothesis be supported or rejected based on the experiment?
10. This experiment led to the development of what major medical advancement?