To test the effect of vitamin D on growth, two groups of rats were raised under identical conditions and fed the same diet. One of the groups received daily injections of vitamin D. The other group received injections of saline, which did not contain vitamin D. All the rats were weighed weekly for 2 months. In this experiment, the control was the
A) group receiving vitamin D.
B) 2-month period of time.
C) average weight gain of the rats.
D) group receiving saline.

Question

Quizplus · Accepted Answer

The control in an experiment is the group that does not receive the experimental treatment. In this case, the group receiving saline serves as the control because it does not receive vitamin D, allowing for a comparison to determine the effect of vitamin D on growth.

To Test the Effect of Vitamin D on Growth, Two