Carrie is testing the effects of nitrogen concentrations on the growth of algal cells. her experimental treatment consists of algal cells in beakers, each containing a different concentration of nitrogen dissolved in water. what would be the best control to use in her experiment?

Carrie is testing the effects of nitrogen concentrations on the growth of algal cells. her experimental treatment consists of algal cells in beakers, each containing a different concentration of nitrogen dissolved in water. She should use a beaker containing boiled water as a negative control for the experiment. The algal cells will not grow in absence of any Nitrogen, hence the negative control will have no growing populations of algal cells. This control will add a data point for zero nitrogen concentration in the data set of varying nitrogen concentrations in the beaker.