Question

time that plants grow a little more slowly with ultraviolet light.

experiment 2: a student did a test to see if a new fertilizer makes roses bloom earlier. she followed a logical method and used a control group and experimental groups. she performed one experiment and found that the fertilizer had no effect.

which experiment is more likely to be reliable, and why?

a. experiment 1, because the results supported the hypothesis
b. experiment 1, because it gave the same results every time
c. experiment 2, because the setup included a control group
d. experiment 2, because it followed a logical method

Explanation:

Reliable experiments require controlled setups to isolate variables. Experiment 2 used a control group (standard for comparison) and experimental groups, which is a key feature of valid scientific design. While it mentions a logical method, the inclusion of a control group is the most critical factor for reliability here—control groups help rule out alternative explanations for results. Experiment 1's details are incomplete (no mention of controls or replication), so Experiment 2 is more reliable due to its control group.

Answer:

C. Experiment 2, because the setup included a control group