Science projects are an effective way to teach inquiry and the scientific process skills of questioning, predicting, observing, measuring, planning investigations, and drawing conclusions based on evidence. Science inquiry requires critical and logical thinking, using tools to collect and interpret data, and communicating the findings with others (The National Science Education Standards, 1996).
The purpose of teaching inquiry-based science is for students to transfer and apply these skills to solve real-life problems. Usually, the problems are directly related to people, places, and events so they can be naturally integrated with the social studies curriculum. Science projects can be used to communicate important ideas about environmental issues and increase our knowledge and resources. This information can make a difference in our lives. It can also lead to further research and action. The focus of this article is to describe how an elementary student used inquiry-based science to investigate crop damage and how a high school student used inquiry-based science to demonstrate how water hyacinths can be used to absorb toxins in drinking water.
In Davis, California, a sixth grader's science experiment redirected the research of U.C. Davis scientists. He discovered that female naval orangeworms - a crop damaging pest - preferred pistachios over almonds or walnuts. Gabriel Leal liked the taste of pistachios better and hypothesized that these orangeworms would feel the same. Gabriel's science project involved placing egg-filled orangeworms in a cage with 4 traps: one filled with shelled pistachios, one with almonds, one with walnuts, and one empty. Each cage of nuts had 50 grams, and the empty cage provided the control for the experiment. After two nights, Gabriel counted the number of eggs laid in the traps, and found that most of the eggs were laid in the pistachio cage. This contrasted with the belief that orangeworms prefer almonds, and fruit growers usually use orangeworm traps baited with almond oil. However, Gabriel's father, an entomologist at U.C. Davis, explained that the chemical from the almond "competes with the synthetic material in the traps" (Keatley, 2009) Using pistachios instead of almonds in the traps, could solve this problem. Gabriel's findings were reported at the California Almond Industry Conference in Modesto, and has led to new research at the U.C. Davis Chemical Ecology lab.
Katie VanderWeele, a high-school student in
Oregon , read about the arsenic crisis in the country of Bangladesh's water supply in Scientific American Magazine in 2004. This dangerous toxin is found in one third of the drinking wells, and natural erosion caused it to seep into the groundwater from the surrounding rocks and soil. Arsenic sickness can cause thickening and discoloration of the skin, vomiting, numbness in hands and feet, blindness, and cancer (CDC). Once it is diagnosed, there is no cure, and only some relief can be provided for the symptoms. More than 30% of the wells in Bangladesh contained 0 .3mg/L of arsenic, or more. This high level is much more dangerous than the 0.01mg/L that is determined unsafe by the World Health Organization.
Katie researched further, and found that some plants such as the water hyacinth, naturally absorb toxins. So she designed an experiment to see how much toxin could be removed from the arsenic-contaminated water by the hyacinths before they reached a saturation point and released the arsenic back into the water. She floated 14 hyacinth plants in 20 liters of water. Then (with safety precautions) she added 300 micrograms of arsenic per liter. After 24 hours , she tested the arsenic level in the water, and if the plants had absorbed the toxin, she added more arsenic to once again equal 300 micrograms per liter. After five days, the plants had reached saturation point and would not absorb any more. Katie concluded that these plants would need to be removed from the water once they had absorbed the maximum amount of arsenic. …