Question

passage below describes an experiment.
dr. jackson collected two species of algae, chlorella rotunda and tetraselmis cordiformis. he wanted to know whether one species released more oxygen as it grew than the other. to find out, dr. jackson prepared six culture tanks. he filled each tank with the same amount of a mixture of water and nutrients. then, he added 1,000 live algae cells to each tank and sealed the tanks. to three of the tanks, he added c. rotunda cells. to the other three, he added t. cordiformis cells. after five days, dr. jackson measured the amount of oxygen in each culture tank.
complete the sentence.
in this experiment, the amount of oxygen in the tanks was ______.
a dependent variable
an independent variable

Explanation:

In an experiment, the dependent variable depends on the independent variable. Here, the type of algae (independent variable) affects oxygen production. So oxygen amount is dependent on algae species, making it a dependent variable.

Answer:

a dependent variable