Question

ults and Discussion: Describe your sketches of your microscopic observations. γ 2mwg hin How can you distinguish between cell-wall potassium and accumulated potassium in the guard cells? e Why did you pre-treat the corn leaf sections with CaCl2 prior to staining with cobaltinitrite? . What is the photosynthesis mode (C-3 or C-4) of the plant you analyzed? . Can you distinguish between different photosynthetic modes (ie, c3, c4, or CAM) by analyzing stomatal closure/aperture? Explain. ography Gibson, A.C. and P.S. Nobel. 1986. The Cactus Primer. Harvard University Press, Cambridge Mass. oster, A.S. and E.M. Gifford, Jr. 1974. Comparative Morphology of Vascular Plants, 2t ed W.H. Freeman and Co., San Francisco. Pp. 52, 478-482. Meidner, H. 1984. Class Experiments in Plant Physiology. George, Allen & Unwin, London

Answer 1

The two guard cells are present surrounding each stomata which regulate the opening and closing of stomata to facilitate gas exchange and controls the transpiration.

In dark, the guard cells become flassid due to loss of water and decrease in osmotic pressure, turgor pressure and volume of cells and so, change their shape. As a result, stomatas are closed.

In light, the guard cells become turgid due to uptake of water and rise in osmotic pressure, turgid pressure and volume of cells. And as a result, stomatas are open.