Final answer:
The experimental setup described lacks a control group based on the information provided, as no standard or traditional treatment is mentioned for comparison. Control groups are essential for determining the effectiveness of different conditions or treatments in an experiment.
Step-by-step explanation:
The question at hand pertains to whether the setup of an experiment with mice growing at a faster rate and being fed two different types of food has a control group. A control group is a standard to which comparisons are made in an experiment. However, since the provided information does not indicate that there is a group of mice that is either not receiving any treatment or receiving standard treatment, it can be concluded that this setup lacks a control group. If one of the groups of mice is receiving a more traditional diet which has previously been fed to mice in this kind of experiment, that group would be considered a control group, but as per the given details, no such group has been described.
For instance, in an experiment with multiple groups, we could reference Figure 45.42 from another study where rat groups were subject to different conditions involving food rewards at various trials. Here Group I served as the control because they found food at the end of each trial, while groups II and III had varying access to food, allowing for a clear comparison to the control. In the corn fertilization example provided, row 2 without fertilizer represents the control that allows comparing the effect of the fertilizer on row 1, since all other conditions are kept constant.
Similarly, in studies where diets or nutrition are assessed, such as the one by Blanton et al., the control group would be GF mice receiving microbiomes from healthy children, contrasting those receiving microbiomes from undernourished children. It's also essential for the experimental design described by the three students testing different nutritional formulas on rats; here a control group would be one that receives a standard rat formula known not to affect weight gain significantly.