<em>The independent variable would be the amount of copper fed into the experimental rats.</em>
An independent variable during an experiment is a variable whose value is not dependent on any other variable being measured in the experiment.
The value of an independent variable is not changed by any other variable in an experiment. In actual fact, the effect of the independent variable is being tested on other variables (dependent variables) in the experiment.
<u>Hence, in an experimental study of the effect of copper deficiency on coat color in rats, the amount of copper fed into the system of the rats will be varied and the effects of this variation on the coat color of the rats would be observed by measuring relevant variables. Therefore, the amount of copper is the independent variable.</u>
