A scientist wants to determine how temperature affects photosynthesis? He sets up a controlled experiment in which he places sma
ll plants acquired from an aquarium store into 3 separate test tubes. He pours 20 ml of cold water into one test tube, 20 mL of room temperature water into the second test tube, and 20 mL of warm water into the third test tube. He covers each test tube with a small latex balloon and measures the circumference of each balloon after 2 days. What is the test (independent0 variable?
The independent variable of an experiment is the variable that the experimenter changes or manipulates in order to effect an outcome or response in the measured variable/dependent variable.
In this experiment, a scientist wants to determine how temperature affects photosynthesis. He sets up the experiment by adding 20ml of water at different temperatures to three test tubes. Hence, the independent or experimental variable is the DIFFERENT TEMPERATURES GIVEN TO EACH PLANTS IN THE TEST TUBE because it is what the experimenter changes in order to effect a measurable outcome i.e. oxygen released in each balloon as a result of photosynthesis, which is the dependent variable
