Question

question 1 (1 point)
(01.01 mc)
a scientist is investigating the effects of salinity on fish development in the atlantic ocean. he places fertilized fish eggs in an aquarium that contains lower salinity than typical atlantic ocean water. he observes that the fertilized eggs fail to develop. he concludes that fish eggs do not develop in conditions with low salinity. why is this an invalid conclusion?
o a the experiment lacks an experimental group.
o b the experiment does not measure any dependent variables.
o c the experiment does not have a group tested in normal salinity.
o d the experiment changes more than one variable at once

Explanation:

In a proper experiment to test the effect of salinity on fish - egg development, there should be a control group (with normal salinity) and an experimental group (with low salinity). Here, the scientist only has the experimental group (low - salinity aquarium). Without a group tested in normal salinity (the control), it's impossible to be sure that the lack of development is only due to low salinity. For example, there could be other factors in the aquarium (unrelated to salinity) that are causing the eggs not to develop. But if there was a normal - salinity group (control) where eggs developed and the low - salinity group (experimental) where they didn't, the conclusion about salinity would be more valid.

Answer:

C. The experiment does not have a group tested in normal salinity.