Which variable is the dependent variable--the variable that depended on the treatment and was measured by the researchers? is the dependent variable on the x-axis or the y-axis?

Answers:

1)  Yes.  The "variable that depended on treatment and was measured by the researchers" is, in fact, the "dependent variable".

2) The "dependent variable" is on the "y-axis" ; whereas the independent variable is on the "x-axis" .

There is nothing there