Sue is setting up an experiment to test whether fly maggots select a dark or a brightly lit environment. She sets up a chamber in which there is a gradient in light intensity from one end (dark) to the other (brightly lit).
The experimental hypothesis was
“There will be a large difference between the number of maggots in a dark environment and the number in a brightly illuminated one.”
What is the dependent variable? Select one option from the list below.
1)Light intensity
2) The reaction rate of maggots
3) The average number of maggots in each light condition after 5 minutes
4) The total number of maggots
5) The number of maggots in each light condition
6) The distance between the darkest and most brightly lit parts of the choice chamber
7) The time of day
5 or if the experiment is replicated, 2
An independent variable is the potential stimulus or cause, usually directly manipulated by the experimenter, so it could also be called a manipulative variable.
A dependent variable is the response or measure of results.