Describe4 marksStandard
The table below shows the mean stomatal aperture (width in micrometres) measured every 2 hours over a 24-hour period in leaves of a soybean plant (Glycine max) under normal conditions (light from 06:00 to 18:00, dark from 18:00 to 06:00).
| Time (hours) | Stomatal aperture (µm) |
|---|---|
| 00:00 | 1.2 |
| 02:00 | 1.0 |
| 04:00 | 1.1 |
| 06:00 | 2.0 |
| 08:00 | 5.5 |
| 10:00 | 7.8 |
| 12:00 | 8.0 |
| 14:00 | 7.5 |
| 16:00 | 5.0 |
| 18:00 | 2.5 |
| 20:00 | 1.5 |
| 22:00 | 1.3 |
Describe the daily rhythm in stomatal aperture shown in the table and the mechanisms by which stomata open and close in response to environmental conditions, including the role of abscisic acid (ABA).