Eve and James are having a disagreement over how to achieve the best growth in plants. Eve thinks that natural rainwater is better for plant growth than water from the tap. She believes that chemicals from the tap water will leech into the water and pollute the plant. James disagrees. He thinks that natural rainwater has too many chemicals from the atmosphere and tap water is better.
They do some research and find that plants must take in nutrients from the surrounding environment to grow. Nitrogen and phosphorous, in particular, encourage growth because they are instrumental in photosynthesis. This is why they are common ingredients in plant fertilizers. When agricultural runoff pollutes waterways with nitrogen- and phosphorous-rich fertilizers, the nutrient-enriched waters often see an increase in algae growth. Water pollution that alters a plant’s surrounding pH level, such as acid rain, can harm or kill the plant. Acid rain forms because of atmospheric sulfur dioxide and nitrogen dioxide, which are emitted from natural and human-made sources. These include volcanic activity and burning fossil fuels. These compounds interact with common atmospheric chemicals, including hydrogen and oxygen, to form sulfuric and nitric acids in the air. These acids return to earth through precipitation, such as rain or snow. Once acid rain reaches the ground, it flows into waterways that carry its acidic compounds into bodies of water. Acid rain that collects in aquatic environments lowers water pH levels, harming plants that cannot tolerate higher acidic conditions.
They decide to set up an experiment to see whose prediction is correct. They decide to buy two identical plants, the same size and species. They put one plant outside and one plant inside away from the rain. When it rains, they water the plant inside with water from the tap.
A fellow classmate wants to perform a similar experiment and compare data, instead of watering the plants with rainwater or hose water, she waters them with bottled spring water. Is this acceptable? Why or why not? Choose two of the following responses.
A fellow classmate wants to perform a similar experiment and compare data, instead of watering the plants with rainwater or hose water, she waters them with bottled spring water. Is this acceptable? Why or why not? Choose two of the following responses.
No, this is not acceptable, because changing the type of water changes the IV of the experiment.
No, this is not acceptable, because spring water is the same as rainwater.
Yes, this is acceptable, because bottled spring water is still a type of water.
Yes, this is acceptable, because another level of the IV provides more data for comparison.
No, this is not acceptable, because data should not be compared unless the same person is carrying out the procedure for each trial.
No, this is not acceptable, because changing the type of water changes the IV of the experiment.
Yes, this is acceptable, because another level of the IV provides more data for comparison.