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.
Based on the scenario and background information, which of the following would be the best option for the testable problem statement for the students to use for their experiment?
Based on the scenario and background information, which of the following would be the best option for the testable problem statement for the students to use for their experiment?
How does the type of water affect plant growth?
What type of plant grows best outside?
Does the amount of water affect the growth of a plant?
What type of water produces the most fruit in plants?