Two students are planning an experiment that will test how planaria (aquatic flatworms) respond to different environments. They
will conduct two investigations—one that tests the worms’ responses to different water temperatures and one that tests the worms’ responses to different levels of acidity. Student 1 wants to buy two groups of flatworms and use a different group for each investigation. Student 2 thinks the same group of worms should be used for both investigations. Do you think either student’s method would give more accurate results? Why or why not? Explain your response.
Student 2 is correct and the same group of worms should be used.
<h3>What is an experiment?</h3>
An experiment is the process by which we establish cause and effect relationships in science. The control variable are those that must be kept the same in the experiment.
We know that the experiment will only be valid if the research is carried out with the same group of worms. If different groups of worms are used, other factors may account for the results obtained.
Thus student 2 is correct and the same group of worms should be used.
