A student wants to perform an experiment to test the effect of different colored lights on the growth of basil plants. She sets
up an experiment where multiple basil plants are placed in six different setups; one with red light, one with green light, one with yellow light, one with blue light, one with no light and one with sunlight. In each setup the plant receives the same amount of water, soil, and size of container. What is the independent variable in this experiment
light is the independent variable, height of the plant is the dependent variable. Dependent is the effect that based on the independent.
Explanation:
lets break it down. 1) you want to know the effect of something you apply from one thing to another. Let say, if you grow your plants under the sunlight, the plants grow taller. In this case, the sunshine is the independent variable whereas the height of the plant/how tall it can grow is the dependent variable. 2)NOW, before i give the answer. The design of the question is not good for high school students. i think your teacher thinks "light" is the independent variable. 3)However, the question contains confounding variables in it because different lights might produce different effects to the height of the plants. If you want to test if plants are exposed to light grows taller than plants do not expose to light, then you should have all the lights are the same. 4) So, all the plants should be exposed to one certain light to avoid confounding. Confounding means that either red light and sunlight are both produce the same effect whereas the other colors do not help the plants to grow taller. 5)Your teacher should test one light at a time. So, if he is testing with all different colors of light, then light is the independent variable, and height of the plant is the dependent variable.
