Because the plant is unaffected as the worms benefit
The three liquids will form three layers, the bottom layer is more dense and the top layer is less dense
<span>One group is given a larger dosage than is typically prescribed.
A second group is given a smaller dosage than is typically prescribed
Then results of the groups are compared to each other.
The thing that is missing in this experimental design is a third group who are tested with the typical dosage.</span>
