PLANTS
TRANSPORT IN PLANTS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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They do not contain cytoplasm
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They contain companion cells
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Their end walls have not been completely broken down.
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They transport sugars only.
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Detailed explanation-1: -Phloem is composed of sieve tube elements, companion cells, phloem parenchyma and phloem fibres. sieve tubes are longitudinally arranged cells. It is seen associated with the companion cells. Sieve tubes contain large cytoplasm without nucleus and its activity is controlled by sieve tubes.
Detailed explanation-2: -The companion cells and Sieve tubes maintain close cytoplasmic connections with each other through fine pits. Hence, tracheids are not an element of phloem tissue, so the correct option is (1) Tracheids.
Detailed explanation-3: -The cells of phloem are called sieve tubes, which contain cytoplasm but no nucleus.
Detailed explanation-4: -So, the correct answer is ‘Peripheral cytoplasm, a large vacuole and a prominent nucleus; all are absent in a mature sieve tube element’