Coloured scanning electron microscopy (SEM) of a stoma opening and closing. A stoma is a tiny pore which regulates gaseous and water exchange in plants. The stoma is controlled by its two flanking guard cells. The stoma opens in the day to allow carbon dioxide to enter the leaf. However this can lead to excessive water loss through evaporation. When water levels are low, the guard cells close the stoma to prevent more being lost. | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Berrod, Thierry |
Modell-Rechte: | nicht erforderlich |
Länge: | 4 Sekunden |
Seitenverhältnis: | 16:9 |
Restrictions: | - |