Question

the passage below describes an experiment.
image of a person using a microscope every day at work, ruth made a large cup of tea that she drank throughout the morning. she wondered how much bacteria might be growing in her cup of tea as the morning went on. to find out, ruth filled three identical cups with tea and placed them on her desk for three hours. after the first hour, she placed a drop of the tea from each cup on a separate microscope slide and counted the number of bacteria in the drop. ruth repeated this with each cup of tea after the second hour, and again after the third hour.
caption: using a microscope to count bacteria on a slide
complete the sentence.
in this experiment, the number of bacteria in a drop of tea was ______.

a dependent variable

an independent variable

Explanation:

In an experiment, the dependent variable depends on the independent variable (here, time). Ruth measures bacteria count (dependent) over time (independent). So bacteria count is dependent.

Answer:

a dependent variable