How do guard cells regulate opening and closing of stomatal pores?
By increasing and decreasing osmotic potential of cell sap of gaurd cells the opening and closing of stomata take place.
What is the difference between guard cells and epidermal cells and how it relate to the difference in their functions?
epidermal cells form the outermost layer of cells of the organism. guard cells control opening and closing of any pore like in the case of stomata, epidermal cells provide protection and guard cells take care of opening and closing of stomatal pore depending on the plant's need of carbon dioxide or oxygen.
Guard cell is an epidermal cell that is also a multisensor hydraulic valve. The guard cells surround the stomatal pore which controls the opening and closing of the stomatal. Due to tugor changes,the guard cells can be triggered by light, temperature, carbon dioxide concentration and hydration of the leaf. Ex: The guard cells are triggered by a high temperature and closes the stomatal pore to conserve water.
There's really isn't a black and white question to this answer. Guard cells when open allow for CO2 and Oxygen to diffuse into the spongy mesophyl, while at the same time this causes water to evaporate at a higher rate through the stomata. There is a fine balance between stomatal opening (Guard cell is turgid) and stomatal closing (Guard cell is flaccid). For example the Guard cells might swell at night so that CO2 and…
The movement of gases into and out of leaves is through the stomata, pores in the leaf or stem. The cells called "guard cells" control the opening and closing of the stomata. (The plural is stomata - Latin for holes - and the singular is stoma.) The opening in the leaf called the stomata and the guard cells that control the opening and closing of the stomata.
The stomata's function is to allow gas exchange with the surrounding air, so that the plant can intake carbon dioxide and oxygen. Stomatal opening is favored when there is plentiful water and moderate temperatures. Abscissic acid, a plant hormone, acts on the guard cells to open and close stomata. Some plants are even genetically engineered with a mutated era gene, which makes them more sensitive to abscissic acid and more prone to the opening and…
---- Stomata are microscopic pores found on the under side of leaves. You will find the stomata in the epidermal tissue. The stomata is bounded by two half moon shaped guard cells that function to vary the width of the pore. Each guard cell contains chloroplasts. The glucose concentration of the the cells changes with the photosynthetic activity and therefore it is the guard cells that regulate the opening and closing of the stoma. ----
Stomatal pores close if excessive water loss occurs. As long as there is sufficient water in the soil to replace the water that is being lost by a plant, stomata stay open. Low concentrations of CO2 also cause the stomata to open source. The stomata's function is to allow gas exchange with the surrounding air, so that the plant can intake carbon dioxide and oxygen. Stomatal opening is favored when there is plentiful water and…
Guard are cells surrounding each stoma. They help to regulate the rate of transpiration by opening and closing the stomata. To understand how they function, study the following figures. As you look at the figures, keep in mind that an increase in solute concentration lowers the water potential of the solution, and that water moves from a region with higher water potential to a region of lower water potential.
How does the net gas exchange between the air and the cells of the mesophyll take place in the dark?
The opening and closing of a stomata depends on its environmental factors, the most important being light, carbon dioxide concentration in the leaf tissue, and water supply. Stomata tend to open during daylight in response to light, and close at night. Low CO2 levels also promote stomatal opening. Conditions that include water stress causing the stomata to close, regradless of light or CO2 levels.
The guard cells synthesize glucose through photosynthesis in the presence of light. as glucose accumulates, osmotic pressure increases and this enables them to draw water from adjacent epidermal cells by osmosis. this makes the guard cells turgid and the stomata opens. at night, there is no photosynthesis and therefore glucose levels go down leading to lowering of osmotic pressure. guard cells lose turgidity and become flaccid and therefore stomata closes. Am sure you can derive…