Question

Question
A student adds different amounts of fertilizer to bean plants. All other conditions are kept the same. Explain how this test shows if fertilizer affects plant growth. Write your answer in 1-2 sentences.

(2 points)

Answer 1

Because the amount of fertilizer is the only variable changed while light, water, soil and temperature are kept constant, any consistent differences in plant growth can be attributed to the fertilizer. Comparing growth of plants given different fertilizer doses (including a no-fertilizer control) shows whether and how fertilizer affects growth.