Bright Light: Mary wanted to conduct an experiment to determine if the color of light changes how a plant grows. She selected four different colors of light to use: red, white (normal), green, and blue. She used the same type of plants, gave them the same amount of water and exposed them to the same amount of light each day. She grew 3 plants in each light for one month and measured each plant's growth twice a week. After one month, she found that plants grow best in white light. Identify the independent variable.

color of light

Explanation:

The independent variable is the variable that is supplied and often varied/manipulated by the researcher during the course of experiments. It is varied/manipulated in order to see the effect it will produce on another experimental variable - the dependent variable.

In this case, out of all the variables supplied by Mary, only the color of light supplied was varied - red, white, green, and blue; other variables supplied were kept constant. Hence, the independent variable is the color of light.

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