PLANT PHYSIOLOGY
TRANSPORT IN PLANT
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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covering the shoot with a black plastic bag
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covering the shoot with a clear plastic bag
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removing the leaves from the shoot
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shining a bright light onto the shoot
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Detailed explanation-1: -The xylem cells make up a tube starting from the leaves, down the stem, till the roots. This creates a drinking straw from which the water travels from the roots to the leaves. Hence, if the rate of transpiration increase, the uptake of water from the roots and the shoots also increases.
Detailed explanation-2: -We may conclude that root water uptake depends on a number of factors such as soil hydraulic conductivity, rooting depth, root density distribution, soil moisture pressure head, demand set by the atmosphere (’potential’ transpiration) on the plant system, and the presence of a water table.
Detailed explanation-3: -Plants transpire more rapidly in the light than in the dark. This is largely because light stimulates the opening of the stomata (a mechanism). Light also speeds up transpiration by warming the leaf. Plants transpire more rapidly at higher temperatures because water evaporates more rapidly as the temperature rises.
Detailed explanation-4: -The transpiration rate is directly proportional to the absorption of water by the roots from the soil. A decrease in water absorption causes the closure of stomata and wilting, thereby reducing the rate of transpiration.