PLANTS
TRANSPORT IN PLANTS
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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(i) a leaf (ii) a growing apple
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(i) the trunk (ii) a leaf
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(i) the roots (ii) a growing shoot
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(i) a growing shoot (ii) a leaf
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Detailed explanation-1: -Water flows up from the roots, through the trunk and branches, to the leaves, where it is used in photosynthesis. Alongside xylem is another system of tubes called phloem, which transports the glucose formed in photosynthesis into the branches, fruit, trunk and roots of the tree.
Detailed explanation-2: -The mechanism by which sugars are transported through the phloem, from sources to sinks, is called pressure flow. At the sources (usually the leaves), sugar molecules are moved into the sieve elements (phloem cells) through active transport.
Detailed explanation-3: -Y: In phloem the direction of movement of phloem sap is bidirectional. Z: In xylem the movement of water and mineral is unidirectional.
Detailed explanation-4: -The increase of sugars lowers the water potential in the phloem and therefore draws in water down a concentration gradient by osmosis. This increase in water causes an increase in pressure within the phloem which causes a mass movement towards the roots.