8. One of the scientists wants to run the experiment a second time but provide different amounts of oil for each colony of bacteria. How would this affect the validity of any conclusion for this experimental design? *
1 point
A It would be valid because three different bacteria were tested.
B. It would be valid because the experiment was conducted two times.
C. It would not be valid because the amount of bacteria will still consume the oil.
D. It would not be valid because the amount of oil provided is not being controlled.***
agree
The correct answer is D. It would not be valid because the amount of oil provided is not being controlled.
To understand why this is the correct answer, let's break it down. In any scientific experiment, it is crucial to control all the variables except the one being tested. This ensures that any observed effects can be attributed to the independent variable (in this case, the amount of oil) and not to any other factors.
In the given scenario, the scientist wants to vary the amounts of oil provided to each colony of bacteria in a second run of the experiment. However, by doing so, they are introducing an additional variable into the experiment that is not being controlled. The variation in the amounts of oil may affect the growth or behavior of the bacteria differently, making it impossible to isolate the independent variable and draw accurate conclusions.
In order to maintain the validity of the experiment, the scientist should control the amount of oil provided to each colony of bacteria, keeping it constant for all the trials. Only then can any observed differences in the growth or behavior of the bacteria be confidently attributed to the varying amounts of oil, rather than any other uncontrolled factors.