Answer;
-Controls
Explanation;
A control is something that is used as a standard of comparison for checking the results of an experiment. A control is important for an experiment because it allows the experiment to minimize the changes in all other variables except the one being tested.
There will frequently be two groups under observation in an experiment, the experimental group, and the control group. The control group is used to establish a baseline that the behavior of the experimental group can be compared to.
-Without an experimental control group, it is difficult to determine the effects of the independent variable on the dependent variable in an experiment.
