Final answer:
The control respirometer in an experiment measuring respiration would be the setup without a living organism. It accounts for non-respiratory changes in gas volume. Adding potassium hydroxide to the setup can absorb CO2, allowing accurate measurement of O2 consumption.
Step-by-step explanation:
In an experiment using respirometers to measure the rate of respiration in mice, one of the respirometers must serve as a control to ensure that the results of the experiment are valid. The control respirometer would contain all of the same components as the experimental setups, minus the living organism (mouse, in this case).
This allows the experimenter to account for changes in gas volume that are not related to the mouse's respiration, such as changes due to atmospheric pressure or temperature fluctuations. Therefore, the control provides a baseline for comparison.
To account for the production of carbon dioxide, a substance such as potassium hydroxide (KOH) can be added to the respirometer setup to absorb CO2. This ensures that changes in gas volume are due to oxygen consumption alone, providing a more accurate measure of the rate of respiration.