In a study on how light level affects plant growth, which is the independent variable?

In a study on how light level affects plant growth, which is the independent variable?

• A. Light level
• B. Plant height
• C. Soil moisture
• D. Temperature

Answer: (A)

The main idea here is identifying what the researcher changes to see its effect. In a study about how light level affects plant growth, the factor being varied is the amount of light. That makes light level the independent variable. What you measure in response to that change is plant growth, such as height or biomass, which is the dependent variable. Other factors like soil moisture or temperature could influence growth, but in a well-designed test they’re kept constant or controlled so they don’t confound the effect of light.

The main idea here is identifying what the researcher changes to see its effect. In a study about how light level affects plant growth, the factor being varied is the amount of light. That makes light level the independent variable. What you measure in response to that change is plant growth, such as height or biomass, which is the dependent variable. Other factors like soil moisture or temperature could influence growth, but in a well-designed test they’re kept constant or controlled so they don’t confound the effect of light.