Question

repeated with fish from each tank. the study showed that fish raised in elevated co₂ levels did not avoid the sounds of the predator fish. they spent approximately the same proportion of time at the speaker end of the aquarium before and after the sounds of the predator fish were played. however, the fish from the aquarium with the normal atmospheric co₂ pressure avoided the speaker end of the aquarium after the predator sounds were played. question: what are the independent and dependent variables in the investigation? a independent = co₂ pressure, dependent = position of fish b independent = number of eggs in aquarium, dependent = co₂ pressure c independent = position of fish, dependent = number of eggs in aquarium d independent = temperature of the water, dependent = co₂ pressure

Explanation:

The study manipulates CO₂ pressure (elevated vs normal) and observes the position of fish (whether they avoid the speaker - end or not). The independent variable is what is changed by the researcher, which is CO₂ pressure, and the dependent variable is what is measured as a result of the change in the independent variable, which is the position of fish.

Answer:

A. Independent = CO₂ pressure, Dependent = Position of fish