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. group receiving saline.
C. average weight gain of the rats.
D. 2-month period of time.
Answer:B
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. group receiving saline. C. average weight gain of the rats. D. 2-month period of time.