The independent variable is a variable that is being manipulated or controlled. This is to see how it affects, changes and yields the outcome of the particular stimuli.
The dry ice experiment has an IV of temperature and a DV of melting time.
Big grasshoppers, because it does not involve a number.
Hope this helps! <3
D. Fish
The brain is part of an organism's central nervous system. Simpler organisms such as sponges, hydrae, and flatworms lack the complexity in their central nervous systems to have a brain. A fish, on the other hand, is complex enough to have a central brain.