. For this experiment, the independent variable is the composition of the test specimen. The dependent variable is the growth of the bacteria colony. This is determined by measuring the size of the growth using a ruler. The constants (control variables) are the room temperature, the amount of sunlight and the ingredients in the petri dish agar. 2. The petri dish prepared with the blood agar must be stored in a refrigerator. Before the start of the experiment, remove the petri dish from the refrigerator to allow it to reach room temperature. 3. Three test specimens are made and .....