1. Whatare controlled (constant) variables? In your experiment, name two variables that you will keep constant (controlled)?Why is it necessary or helpful to control these two variables in your experiment? Example: For the bread mix experiment,two controlled variables will be the oven temperature and the baking pan. These must be the same for both the breadmixwith yeast and the one without yeast.If Ididn'tcontrol the temperature and the baking pan, the height of the loaf(dependent variable)could be due to oven temperature or the baking pan rather than due to the addition of yeast.