I need help with this. I will give brainliest. Melanie gathers water from different areas of the pond by her school. She puts growing solution into 4 different shallow dishes. She puts one drop of water from different areas of the pond into three of the dishes. She leaves one dish with only the growing solution in it and does not add pond water. She covers all the dishes and leaves them on the counter for several days to compare the algae growth in each dish. Why does she have a dish with just the growing solution in it?