Mice are given a protein injection that is designed to promote physical growth.Fifty mice are randomly selected for evaluation in the study.Some of the mice are injected with high levels of the protein, some are injected with low levels of the protein, and a third group receives a placebo (saline injection).The mice's growth is recorded and compared.In this study, the variable is best described as:
A) 50 randomly selected mice.
B) all mice that receive a protein injection.
C) the type of protein used.
D) the amount of protein injected.

Question

Quizplus · Accepted Answer

The variable in this study is the amount of protein injected, as the study is evaluating the effects of different levels of protein injection on physical growth in mice. The other choices (50 randomly selected mice, all mice that receive a protein injection, and the type of protein used) are not the main variable being studied.

Mice Are Given a Protein Injection That Is Designed to Promote