Question

what role did the resting rate play in the bromothymol blue experiment?
a dependent variable
a hypothesis
a control
a null hypothesis

Explanation:

In an experiment, a control is a standard against which changes are measured. The resting rate in the bromothymol blue experiment likely served as a baseline or standard condition to compare other experimental results against. It is not a hypothesis (a proposed explanation), a null hypothesis (a statement of no - effect), or a dependent variable (the variable being measured that changes in response to another variable).

Answer:

a control