Answer:
The correct answer is -
The independent variable - Humidity levels
The dependent variable - Height
The control group - Tree kept outside of the greenhouse
Explanation:
In this study or experiment, the independent variable is the different humidity level as it is what is changed in the study to see its effect on the growth of the redwood tree. The independent variable is manipulated in the experiment to see the change or effect in the dependent variable occurs.
The dependent variable is the variable which \depends on the independent variable as the Independent variable manipulated the dependent variable is measured to the effect which is the height of the redwood trees here.
The control group is a groub of subjects that did not get the treatment that experiment group recieves as it is kept for analysing the deviation from the natural condition. The control group is the redwood trees that are kept in natural environemnt outside of the greenhouse.
