Why did the researchers keep carbon dioxide levels constant while they varied oxygen levels and then keep oxygen levels constant while they varied carbon dioxide levels?
A)It is technically easier to vary the level in the water of one gas at a time.
B)They could only measure the level of one gas in the water at a time.
C)The effects of oxygen and carbon dioxide levels could interact.
D)Only one gas at a time varies in estuaries in the summer.

Question

Quizplus · Accepted Answer

The researchers kept carbon dioxide levels constant while they varied oxygen levels and then kept oxygen levels constant while they varied carbon dioxide levels because the effects of oxygen and carbon dioxide levels could interact. This allowed them to study the independent effects of each gas on the estuary ecosystem. If they had varied both gases at the same time, it would have been difficult to determine which gas was causing the observed changes.

Why Did the Researchers Keep Carbon Dioxide Levels Constant While