Question

Levi decides to examine the effect of fertilizer on the growth of tomato plants. He chooses four plants for his experiment and applies varying amounts of fertilizer to the three of them. He does not apply fertilizer to one plant.

Over a 15-day period, the plants receive fertilizer on Days 1, 4, 7, 10, and 13. Levi measures the height of all of his plants with a meter stick on Days 3, 6, 9, 12, and 15. He also makes sure to hold all experimental factors constant except for the fertilizer.



Which statement describes what Levi did to prepare the control group in his experiment?



Levi applied different amounts of fertilizer to three of his plants.

Levi did not apply any fertilizer to one of his plants..

Levi held all experimental factors constant except for fertilizer., ,

Levi measured his plants on five separate days.

Answer 1

Levi did not apply any fertilizer to one of his plants..

Step-by-step explanation:

In an experiment, there are two major groups namely: control group and experimental group. Control group is the group in an experiment that does not receive the experimental treatment i.e. the group which the independent variable is not applied to.

In this case, Levi is trying to examine the effect of fertilizer on the growth of tomato plants where he used varying amounts of fertilizer on three of the four plants he used for the experiment. The fourth plant did not receive any amount of fertilizer, which is the independent variable (variable being manipulated or changed). This means that Levi prepared the control group in his experiment by NOT APPLYING ANY FERTILIZER TO ONE OF HIS PLANTS.