Question

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., with the other 5 plants receiving 1, 3, 5, 7, Add 9 hours of sunlight. At the end of the experiment she has people try a tomato from each plant and has the has the 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? (1 point)
A) sweetness of fruit
B) number of leaves
C) hours of sunlight
D) amount of water

Answer 1

D) amount of water

She kept the water (and fertilizer) the same for each plant, so water is a controlled variable.