In a model experiment, researchers subjected frogs to various levels of atrazine while keeping all other variables constant. This is an example of a _______ experiment.
A) controlled
B) repeated
C) laboratory
D) comparative
E) None of the above

Question

Quizplus · Accepted Answer

This is an example of a controlled experiment because the researchers kept all other variables constant while subjecting the frogs to various levels of atrazine.

In a Model Experiment, Researchers Subjected Frogs to Various Levels