A biologist wants to test the effectiveness of a new food additive on causing growth in mice.An effective control group would be one that:
A)ate a higher concentration of food additive
B)was kept in different conditions across the city
C)was fed the same ration without the food additive
D)ate a lower concentration of the food additive

Question

Quizplus · Accepted Answer

The control group needs to be identical to the experimental group in every way except for the one variable being tested (in this case, the food additive). Therefore, the best choice for a control group is one that is fed the same ration as the experimental group but without the food additive, so that any differences in growth between the two groups can be truly attributed to the food additive. Choices A and D both involve giving the control group different concentrations of the food additive, which is not a true control. Choice B involves keeping the control group in different conditions, which again is not a true control.

A Biologist Wants to Test the Effectiveness of a New