In the experiment described, the variable that was controlled is the amount of water. The student ensured that each tomato plant received the same amount of water and fertilizer each day, while the hours of sunlight (independent variable) and the sweetness of the fruit (dependent variable determined by the rankings) varied between the plants. The total number of leaves produced can also be considered an observation, but it is not controlled in the sense that it's not kept the same across all plants; it is likely affected by the varying hours of sunlight.
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, with the other 5 plants receiving 1, 3, 5, 7, and 9 hours of sunlight. At then end of the experiment, she had 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?
Hours of sunlight
Amount of water
Sweetness of fruit
Number of leaves
1 answer