Passage
Students studied what conditions help bean seeds sprout. In each trial they placed 20 seeds on damp paper in a covered dish and, after one week, recorded the percentage of the seeds that had sprouted (the germination).
Experiment 1: Giving each dish 10 mL of water per day and equal light, the students kept different dishes at different air temperatures and recorded the germination (Table 1).
| Air temperature (°C) | Germination (%) |
|---|
| 5 | 10 |
| 10 | 40 |
| 20 | 85 |
| 25 | 90 |
| 30 | 60 |
| 35 | 20 |
Experiment 2: Holding the air temperature at 25°C and the light constant, the students gave different dishes different daily amounts of water and recorded the germination (Table 2).
| Water per day (mL) | Germination (%) |
|---|
| 2 | 30 |
| 5 | 70 |
| 10 | 90 |
| 15 | 88 |
| 20 | 55 |
In every trial the same kind of seed and the same covered dishes were used.
