PLANTS
TRANSPORT IN PLANTS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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starch, up and down
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starch, up only
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sucrose, down and up
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sucrose, down only
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Detailed explanation-1: -The photosynthates from the source are usually translocated to the nearest sink through the phloem sieve tube elements. For example, the highest leaves will send sugars upward to the growing shoot tip, whereas lower leaves will direct sugars downward to the roots.
Detailed explanation-2: -Transport in the phloem is therefore both up and down the stem. Sucrose is the transport sugar in the phloem. Transport of substances in the phloem is called translocation . Translocation requires energy as it is an active process.
Detailed explanation-3: -The direction of movement of sugar in phloem is bi-directional as it depends on source-sink relationship which is variable in plants. So, the correct answer is ‘Bidirectional’