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?
Student 1’s methods would be more accurate, because the student would control more factors. Only one variable at a time (either temperature or acidity) would be tested on each group of worms. On the other hand, Student 2 is testing both factors on all the worms, which could make the results unclear.
It looks to be green, which is the color of chlorophyll produced in the chloroplasts. This means that it is found in the green leaves and is used to convert light into energy.
