DR KEITH WHEELER / SCIENCE PHOTO LIBRARY DR KEITH WHEELER / SCIENCE PHOTO LIBRARY
Plant stomata. Light micrograph of stomatal pores on the surface of a kidney bean (Phaseolus sp.) leaf. The stomata are gaps (white) within two guard cells (blue, kidney-shaped). Stomata are pores that regulate the exchange of gases and water vapour into and out of the plant. The guard cells regulate this by expanding and deflating in response to osmotic pressure. When they expand, this causes them to move apart from one another and open the pore. This image was created using an epithelial peel to chemically remove the top layer of the leaf. Magnification: x230 when printed 10 centimetres wide.
Model release not available. Property release not required.