Question

the passage below describes an experiment. read the passage and think about the variables that are described.
camilla liked to make guacamole, but she could often find only unripe avocados at the grocery store. in biology class, camilla learned that ripe fruits produce a gas called ethylene that can cause other fruits to ripen. camilla wondered whether storing ripe bananas with unripe avocados would make the avocados ripen faster.
camilla prepared four paper bags with five unripe avocados in each bag. she added one ripe banana to two of the bags and no bananas to the remaining two bags. then, camilla sealed all four bags. after three days, she opened each bag and counted the number of ripe avocados in each bag.
which of the following was an independent variable in this experiment?
hint: an independent variable is a variable whose effect you are investigating. a dependent variable is a variable that you measure.
the number of ripe bananas
the number of ripe avocados

Explanation:

An independent variable is what is changed or controlled in an experiment to test its effect on the dependent variable. Here, Camilla is testing the effect of the presence of ripe bananas on avocado - ripening. She controls the number of ripe bananas (0 or 1) added to the bags with unripe avocados. The number of ripe avocados is what she measures, so it is the dependent variable.

Answer:

the number of ripe bananas