A Biological Question: Which fertilizer is better: brand A or brand B?The Hypothesis: Brand B, because its advertizement on TV says there is nothing better.
The Experiment:
- Use 3 identical plants.
- Give water to each plant equally on Fridays.
- Plant 1 will just get water.
- Plant 2 will get water with fertilizer A added.
- Plant 3 will get water with fertilizer B added.
- Measure the height of each plant on Mondays.
- Run the experiment for 2 months.
- At the end of the experiment, the best fertilizer will produce the tallest plant.
| Week | Plant # 1 - cm | Plant # 2 - cm | Plant # 3 - cm | 1 | 12 | 12 | 12 |
|---|---|---|---|
| 2 | 12 | 13 | 12 |
| 3 | 13 | 14 | 13 |
| 4 | 13 | 15 | 13 |
| 5 | 14 | 16 | 14 |
| 6 | 14 | 16 | 15 |
| 7 | 15 | 16 | 16 |
| 8 | 15 | 16 | 17 |
Graph the data and answer these questions:
- Which plant served as the control in the experiment?
- What is the independent variable?
- What is the dependent variable?
- Was your hypothesis correct?
- Do you see any problems with the experiment?
- What changes in the procedures would you make?
Use the grid below for your graph. (HINT: the graph will have a line for each plant.) There are 29 squares on the horizontal axis and 23 squares on the vertical axis. Use the How To Page as a guide to making a scientific graph and the Graphing Rubric as a scoring guide.