PLANT PHYSIOLOGY
TRANSPORT IN PLANT
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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On a humid day, the water potential gradient between the intercellular air space and theexternal atmosphere increases to stimulate water loss by evaporation.
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Water arriving at the spongy mesophyll cells via the symplast pathway must move byosmosis through the cell surface membrane before evaporation from the surface of the cells.
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Water diffuses down the water potential gradient from the saturated air space through theguard cells before evaporating from the surface of the cells into the atmosphere.
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Water moves up the xylem in the apoplast pathway and can continue on this pathway byosmosis to reach the spongy mesophyll cells before evaporating into the intercellular airspace.
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Detailed explanation-1: -Solution : Transpiration is the loss of water in the form of vapour from the living tissues of aerial parts of the plant.
Detailed explanation-2: -When the plant is photosynthesising during the day, these features allow carbon dioxide to diffuse into the spongy mesophyll cells, and oxygen to diffuse out of them. To enter the leaf, gases diffuse through small pores called stomata. As the stomata open, water is lost by the process of transpiration .
Detailed explanation-3: -1-Water is passively transported into the roots and then into the xylem. 2-The forces of cohesion and adhesion cause the water molecules to form a column in the xylem. 3-Water moves from the xylem into the mesophyll cells, evaporates from their surfaces and leaves the plant by diffusion through the stomata.
Detailed explanation-4: -The pathway of water is through the root hair cells, root cortex cells and then to the xylem which transports water to the mesophyll cells in the leaves.