Scientists performed an experiment to determine whether there is a connection between learning ability and food. They took two groups of 20 mice each, all from the same purebred strain. The mice were deprived of food for 3 days and then given a standard learning session in running through a maze. They were trained by giving them a mild electric shock whenever they took a wrong turn. Immediately after each learning session, one group of mice was fed, but the other was not, A week later, all of the mice were tested to see whether they could still run the maze correctly. The group that had been fed had retained this ability, but the other group had not. The probable reason that the scientists used only mice from the same pure-bred strain is so that?

The probable reason that the scientists used only mice from the same purebred strain is to minimize genetic variation in the study. By using mice from the same strain, the scientists can reduce the chance that any observed differences in learning ability or food response are due to genetic differences between the mice. This helps to increase the reliability and validity of the experiment, as it allows the scientists to focus on the effect of food deprivation on learning ability without potential confounding factors from genetic variation. Using mice from the same purebred strain helps to ensure that any observed differences in learning ability are more likely to be a result of the specific conditions imposed by the experiment, such as the food deprivation and subsequent feeding, rather than genetic differences between the mice.