Question

For a school project, Chad conducted an experiment to determine whether growing roses under artificial red light instead of in ordinary sunlight affects the number of flowers produced. Chad randomly selected 30 rose plants, all of the same variety. The 30 plants were grown under red light and the nuber of flowers produces was much greater than expected. Based on these data, Chad concluded growing roes under artificial light produces more flowers than does growing in ordinary sunlight. Rohan tells Chad his conclusion is not valid. Which critique of Chad's experiment best supports Rohan's statement?

A. Lack of Control Group
B. Small Sample Size
C. Lack of Replication
D. Inadequate Data Collection

Answer 1

Rohan's assertion that Chad's conclusion is not valid is supported by the critique that Chad's experiment lacked a control group, which is essential for making valid comparisons in an experiment.

Step-by-step explanation:

The critique of Chad's experiment that best supports Rohan's statement that Chad's conclusion is not valid is A. Lack of Control Group. A control group is essential in an experiment to compare results against the conditions being tested. In this case, if Chad only used plants grown under red light with no comparison group grown under normal sunlight, there is no baseline to determine if the increase in flowers is truly due to the red light or if it could have occurred under regular conditions as well. Having a control group would have allowed Chad to compare the number of flowers produced under both conditions and make a more valid conclusion.