The dependent variable is the variable being measured or tested in a given study, while the independent variable isn't changed by the other variables. In this case, the heart rate is dependent on the amount of caffeine, which is then the independent variable. The experimental groups are the groups exposed to the independent variable.
That would be the Compound Microscope, it provides a high magnification that can visibly see movement in the cell, however, it has a low resolution. Hope it Helped!
