In an experiment, if you change the amount of fertilizer to study plant growth, what is the independent variable?

In an experiment, if you change the amount of fertilizer to study plant growth, what is the independent variable?

• A. Plant height
• B. Amount of fertilizer
• C. Weather conditions
• D. Soil color

Answer: (B)

The factor you deliberately change to see its effect is the amount of fertilizer. That makes it the independent variable. The outcome you measure to assess the plant’s response, such as plant growth or height, is the dependent variable. Weather conditions could influence growth but aren’t the factor you’re varying here, and soil color is a property of the soil, not something you’re adjusting to test its effect. In a well-designed experiment, you’d keep weather and other conditions as constant as possible while changing only the fertilizer amount to isolate its impact on growth.

The factor you deliberately change to see its effect is the amount of fertilizer. That makes it the independent variable. The outcome you measure to assess the plant’s response, such as plant growth or height, is the dependent variable. Weather conditions could influence growth but aren’t the factor you’re varying here, and soil color is a property of the soil, not something you’re adjusting to test its effect. In a well-designed experiment, you’d keep weather and other conditions as constant as possible while changing only the fertilizer amount to isolate its impact on growth.