Poison ivy is a weed that grows in New York State. Researchers have found that if poison ivy grows in an environment that contains an increased concentration of carbon dioxide, the plants grow larger and faster. Because carbon dioxide levels in the atmosphere are rising, poison ivy might become a hazard to people who work or vacation outdoors. In order to verify this research, experiments must be carried out. Design an experiment to test the effect of air containing higher than normal concentrations of carbon dioxide on the growth of poison ivy. In your answer, be sure to:

1. state the hypothesis the experiment would test

2. state one way the control group should be treated differently from the experimental group

3. identify two conditions that should be kept the same (constant) in both the control and the experimental groups (1) (2)

4. identify the independent variable

5. describe the type of data to be collected (dependent variable)

6. identify one way you can increase the validity of this experiment