Question 1 Report
| Distance of lamp / cm | 10 | 20 | 30 |
| Bubbles per minute | 40 | 18 | 8 |
Fig. shows the number of gas bubbles given off by pondweed as a lamp is moved further away. What does the data show?
As the lamp is moved away the light reaching the pondweed becomes dimmer, and the bubble count falls from 40 to 18 to 8. Because bubble rate reflects photosynthesis, the data show that the rate of photosynthesis falls as light intensity decreases with distance. There is a clear change, and the plant is still producing bubbles, so it has not died.
Everything you need to excel in your exams