Question

A scientist is investigating the effects of salinity on fish development. He places fertilized fish eggs in an aquarium that contains low salinity and observes their development. What factor would improve experimental design the most? Place the fish eggs in the open ocean because that is the natural habitat Include another aquarium that has normal salinity to compare to the low salinity aquarium Include an aquarium that replaces salt with sugar to confirm that the effects are specific to salt Grow algae with the fish eggs in order to provide adequate nutrients to the developing embryos

Answer 1

B

Explanation: Include another aquarium that has normal salinity to compare to the low salinity aquarium

Answer 2

The correct answer is: Include another aquarium that has normal salinity to compare to the low salinity aquarium

An aquarium with normal salinity would be a negative control.

It is desirable to have a negative control in an experiment because it uses the same components as a primary experiment (performed at the same time on a different population) with no treatment. Negative control is predicted to produce no change to results of interest to the experiment it is only to be compared to.