A scientist adds 5 mcg of the mineral cadmium to the daily diet of 100 4-week-old laboratory mice.After 12 weeks,the researcher weighs and takes blood samples from each mouse.According to her findings,the mice lost weight during the 12-week period,and they have abnormal levels of certain hormones in their blood.Based on this information and your knowledge of scientific research,what would you tell the researcher about her findings?
A)Her results are very interesting,and she should report her findings to nutrition scientists,so they can repeat her study and confirm the results.
B)She needs to conduct more tests on the animals' blood,because her findings are incomplete.
C)The findings are not meaningful or valid because of the way she designed her study.
D)The findings need to be summarized in a research article for submission to a peer-reviewed nutrition journal.

Question

Quizplus · Accepted Answer

The study was poorly designed because it lacks a control group for comparison. Without a control group, it is difficult to determine if the changes observed were actually caused by the introduction of cadmium into the mice's diet or by other factors, such as normal growth patterns or individual mouse variation. Therefore, the results are not meaningful or valid. The researcher should redesign the study to include a control group before conducting more tests or reporting findings to other scientists.

A Scientist Adds 5 Mcg of the Mineral Cadmium to the Daily