In this activity, the class will set up an investigation to determine which materials plants need for growth. One of five plants has an appropriate amount of water, light, soil and air. Each of the other four has had one of these eliminated. Students will collect the height and descriptive data about the plants 3 times over 2 weeks, to come to the conclusion that plants must have sunlight, water, and carbon dioxide, and that while soil does help a plant to grow better, a plant can survive without soil.