Nature of Science
The parts of an experiment that stay the same
Controls
Scientists must make their experiment replicable in order for other scientists to...
Verify the results
How does temperature affect the growth of mold?
Experimental
What is an experimental investigation
Scientist design a "fair test" by changing one variable at time. They gather evidence to support or disprove a cause and effect relationship.
True of False: A scientific theory means a "hunch" or a "guess"
False
The variable we are testing. This variable is changed on purpose.
Independent Variable
Which of the following statements describes all the variables in an experiment?
A. All variables are measured to provide data for the experimental results.
C. All variables affect the results of the experiment.
Can plants grow in zero gravity?
Observational
What is a limitation of experimental investigations
Human error
Compare scientific theory to the everyday use of the word theory
Answers vary
Scientific theory is supported by and abundance of evidence
The variable that changes because of the independent variable. For example in the plant food experiment, the plant growth was the __________ variable.
Dependent
A control group in an experiment is
used to give a normal result that scientists can compare experimental results to
Does the height of a ramp affect the distance a toy car will roll?
What type of experiment would need to be done for scientists to answer this question... Do squirrels prefer nuts or berries?
Observational
True of False: A scientific theory never changes
False
Cindy conducted an experiment for her science class. She repeated the experiment three times. Each time, Cindy got a different result. What should Cindy do next?
A. Use the results obtained from the first experiment to draw conclusions.
B. Go over the experimental procedure to make sure there is only one variable
What is an observational investigation
When scientists collect data to draw conclusions about a natural or man-made system.
Is the average height of 6th grade boys greater than 6th grade girls?
Comparative
A few hundred years ago, observations seemed to indicate an idea called spontaneous generation, which stated that living things could appear from nonliving things. In the seventeenth century, experiments were conducted that resulted in observations that disproved this idea. This led to the present day idea that living things can only come from other living things. Which statement best describes what this change in ideas tells us about science?
A. Scientific ideas do not need to be based on only factual and observable evidence.
B. Scientific ideas are not accurate because they constantly change as new evidence is discovered.
C. Scientific knowledge changes because it is open to new evidence as it is discovered and observed.
D. Science is based on factual observations so it should remain the same and not change over time.
C
Describe and give an example of scientific theory
Must be well-supported by facts & data
Confirmed by other scientists through observations and experimentation
Can be changed when there is new evidence available.
Example: Theory of evolution
Jack is planning an experiment to see how temperature can affect the reproduction rate of a certain species of bacteria.
Jack is listing some of the variables that could affect the outcome of the experiment. Which of the following variables should be included on his list?
A. time of year, clothes Jack wears, Petri dish mass
C. temperature, light level, species of bacteria
What is a comparative investigation
Collecting data on different things, or under different conditions to make a comparison.
How will different liquids (sweet tea, soda or punch) affect the growth of a bean plant?
Comparative
The three parts of cell theory
All cells come from preexisting cells
Cells are the most basic unit of life
All living things are made of cells
Describe scientific law and give an example
Must be well-supported by facts & data
Confirmed by other scientists through observations and experimentation
States how something behaves under certain conditions.
It is often stated mathematically.
Example: Law of Gravity