Use the scenario to answer the question. A student is studying the effects of sunlight on tomato plants. She chooses 6 tomato plants, making sure that each of them receives the same amount of water and fertilizer each day. She gives one plant 0 hours of sunlight each day, with the other 5 plants receiving 1, 3, 5, 7, and 9 hours of sunlight. At the end of the experiment, she has people try a tomato from each plant and has them rank the fruits by their sweetness. She also records the total number of leaves produced on each tomato plant. Which variable was controlled in the experiment?

Answer 1

In the experiment described, the controlled variable is the amount of water and fertilizer each tomato plant receives. The student ensured that each of the 6 tomato plants receives the same amount of these resources daily, which helps isolate the effect of sunlight on the plants' growth and sweetness of the tomatoes.