Final answer:
The color of light in the virtual lab experiment is the independent variable because it is manipulated to observe its effect on plant growth, the dependent variable.
Step-by-step explanation:
The color of light in the virtual lab experiment would be considered the independent variable. This is because the independent variable is the one that is changed or controlled by the experimenter to test its effects on the dependent variable, which in this case is the growth of the plant. Other factors such as the amount of water, soil quality, and other environmental conditions should be controlled to ensure that any changes in plant growth are due to changes in the color of light alone. The control would be a plant group that is not exposed to any color change to serve as a basis for comparison, whereas the hypothesis would be a proposed explanation made on the basis of limited evidence as a starting point for further investigation.