A biologist hypothesizes that restricting food from mice will decrease their activity. He designs an experiment in which he observes the activity of 50 mice under restricted food regimens. Which of the following is true about his study?
A.
The study is well designed since it uses a large sample of mice.
B.
The study does not include a control group.
C.
The study includes too many variables.
D.
The results will allow the biologist to draw a valid conclusion.
I think it's A, can someone check? thanks :)
I don't agree with your choice of A. What is the biologist comparing these 50 mice with? How will restricting the diet of 50 mice prove anything? Also, is 50 mice really a large number. That could be about 7% error.
No control. What is the biologist comparing the 50 mice to?
I agree with no control.
Actually, the correct answer is B. The study does not include a control group.
To understand why, let's first explain what a control group is. In an experiment, a control group is a group that serves as a baseline for comparison. It does not receive the intervention or treatment being tested, allowing researchers to compare the effects of the intervention to the natural or expected behavior.
In this case, the biologist is testing the hypothesis that restricting food will decrease the activity of mice. To establish a control group, the biologist would need to include a group of mice that is not subjected to food restriction. This would allow for a comparison between the activity levels of the mice with restricted food and the activity levels of the mice without restricted food.
Without a control group, the biologist would not have a valid comparison group, making it difficult to determine whether the changes in activity are due to the food restriction or other factors. Thus, option B is the correct answer.
It is important to note that having a large sample size, as mentioned in option A, can be beneficial for statistical analysis and increasing the study's validity. However, the absence of a control group is a more critical issue in this case. Option C is not applicable because limiting the variables in a study is generally preferred, and option D cannot be determined without the necessary controls.