Question

Which experimental procedure would provide the best evidence for the effect of light on plant growth?(1 point)
Responses

Plant seeds of the same variety in the same conditions and vary only the amount of light, then measure plant growth.
Plant seeds of the same variety in the same conditions and vary only the amount of light, then measure plant growth.

Plant seeds in different soils and expose them to different amounts of light, then measure plant growth.
Plant seeds in different soils and expose them to different amounts of light, then measure plant growth.

Measure plants receiving different amounts of light in their natural environments.
Measure plants receiving different amounts of light in their natural environments.

Measure plants of the same variety grown in environments that receive different amounts of light.
Measure plants of the same variety grown in environments that receive different amounts of light.

Answer 1

"Plant seeds of the same variety in the same conditions and vary only the amount of light, then measure plant growth."

This isolates light as the independent variable, keeps other factors controlled, and measures its effect on growth (the dependent variable).