<span>There needs to be an independent variable, a dependent variable, a constant, and a control group. The independent variable is the part that is manipulated. The dependent variable is affected by the independent variable. The constant is the part kept the same throughout all of the experiments. The control group is the normal group that is untreated.</span>
Answer:
voluntary muscle movements
Do you have anymore information to go on with this? Id be happy to help but theres not much to work with. :3