Question

lets say you want to find out if more water helps plants grow taller. you could take two plants, give one more water than the other (independent variable), and then measure how tall they grow. you would need to make sure both plants get the same amount of sunlight, and are in the same type of pot (controlled variables). this would be a fair test! summary - fair tests help scientists learn about the world in a fair way. - in a fair test, you change only one thing to see what happens. - controlled variables are important because they help you know which change caused the result. multiple choice questions answer the following multiple - choice questions about the reading by highlighting the correct answer. according to the passage, what is the most important reason for controlling variables? a. to ensure that the results are due to the independent variable alone. b. to use more materials. c. to make the experiment take less time. d. to make the experiment easier to conduct. in an experiment to determine if different types of fertilizer affect plant growth, which would be the independent variable? a. the amount of water given to each plant. b. the height of the plants. c. the type of fertilizer. d. the type of soil used. what does the passage suggest is a benefit of finding failure points during testing? a. they prove that the initial hypothesis was correct. b. they indicate that the experiment was not a fair test. c. they always lead to unexpected results. d. they help us see what we can improve.

Explanation:

1. Controlling variables isolates the impact of the independent variable. In the plant - water example, keeping other factors like sunlight and pot type the same ensures results are due to water amount (independent variable).
2. In an experiment on fertilizer and plant growth, the factor being changed (type of fertilizer) is the independent variable.
3. Failure points in testing help identify areas for improvement. They don't prove a hypothesis correct, don't necessarily mean an unfair test, and don't always lead to unexpected results.

Answer:

1. A. To ensure that the results are due to the independent variable alone.
2. C. The type of fertilizer.
3. D. They help us see what we can improve.