Drawin's experiments are just one way to study phototroprism. A student wants to investigate the effects of phototroprsm in bean plants. She places a light source directly above one plant, at a forty-five degree angle to another, and at a ninety-degree angle from the third. What is the independent variable.

Angle of light source

Explanation:

Independent variable is the variable that the experimenter changes or manipulates in an experiment in order to bring about a measurable response, which is the dependent variable.

In this question, a student wants to investigate the effects of phototropism in bean plants. She places a light source directly above one plant, at a forty-five degree angle to another, and at a ninety-degree angle from the third. This shows that the variable being manipulated (independent variable) is the ANGLE OF THE LIGHT SOURCE.