Question

1. describe one way the student could make the experiment more valid.
2. what purpose did the untreated cuttings serve in this experiment?

Explanation:

Question 4

To increase experiment validity, a common method is to control variables or repeat trials. For example, the student could repeat the experiment multiple times (e.g., with multiple plant cuttings) to reduce random error, or ensure all conditions (like light, water, temperature) are identical for all experimental groups except the one being tested. Another way is to increase the sample size (use more cuttings) to make results more representative.

In an experiment, untreated cuttings (or a group without the experimental treatment) typically serve as a control group. The control group provides a baseline to compare with the treated group(s), allowing the experimenter to determine if the treatment (e.g., a growth hormone, a specific environmental condition) has an effect by seeing the difference in outcomes between the treated and untreated groups.

Answer:

One way is to increase the sample size (e.g., use more plant cuttings) to reduce random error and make results more representative, or repeat the experiment multiple times under consistent conditions.

Question 5