Question

1. the important data to be recorded in this experiment will come from the observation of the increase in (1) leaf size (2) stem size (3) number of leaves (4) number of roots 21. state the hypothesis being tested in this experiment. 1 22. state one way this experiment could be improved to make the results more reliable. 1

Explanation:

Step1: Analyze the experiment setup

The experiment involves bean seedlings in a nutrient - solution setup with one having aeration (A) and the other not (B). The key factor affected by aeration is root growth as roots need oxygen for respiration.

Step2: Evaluate each option

• Leaf size (1): While leaves are important for photosynthesis, aeration mainly affects roots first, not directly leaf size in the short - term in this context.
• Stem size (2): Similar to leaf size, stem growth is not the most directly affected by aeration in the initial stages compared to root growth.
• Number of leaves (3): Leaf production is not the most immediate response to aeration of the nutrient solution.
• Number of roots (4): Roots need oxygen for respiration and growth. Aeration of the nutrient solution will directly impact root growth and development, so the number of roots is the most important data to record for this experiment.

Step3: Formulate the hypothesis

The hypothesis being tested is likely: "Aeration of the plant nutrient solution will increase the number of roots in bean seedlings."

Step4: Suggest an improvement

One way to make the results more reliable is to increase the sample size. Using more than two bean seedlings in each treatment (aerated and non - aerated) would reduce the impact of individual plant variability on the results.

Answer:

1. (4) number of roots
2. Aeration of the plant nutrient solution will increase the number of roots in bean seedlings.
3. Increase the sample size (use more bean seedlings in each treatment).