Question

Leah is trying to determine how music affects the growth of plants. She hypothesizes that classical music will cause a plant to grow at a higher rate than no music or rap music. She grows nine tomato plants in similar lighting, temperature, and soil. Three are exposed to classical music 24 hours a day, three are exposed to rap music 24 hours a day, and three are grown in complete silence. Leah measures the growth of the plants every day and finds that the plants all seem to have the same rate of growth. What is missing from Leah’s scientific investigation? an experiment that takes careful and regular measurements a specific hypothesis to test with a controlled experiment experimental data that can be recorded and analyzed research on what other scientists have found on this topic

Answer 1

She is missing the control group. As she seems to have nothing to compare the plant’s growth in exposure to music. So Leah would not be able to prove that music affects plant growth if she does not a a control group to compare it with.

Answer 2

Leah's experiment:
A. Takes careful and regular measurements (she measures the growth every day)
B. Has a specific hypothesis and a controlled experiment (the music is the only changing variable, the growth conditions are identical, and this is what she wants to test in her hypothesis)
C. Experimental data that can be recorded and analyzed (measuring the growth of plant fits this)

So the answer must be D, since there is no mention of past research that scientists have found on this topic.