PLANTS
TRANSPORT IN PLANTS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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They have many mitochondria to release energy for transport of food substances.
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They have many mitochondria to release energy for growth of the phloem.
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They have few mitochondria to reduce resistance to flow of substances in the phloem.
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They have few mitochondria as they receive energy released from sieve tube cells.
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Detailed explanation-1: -Once the sucrose enters the companion cells, it can diffuse along the cytoplasmic links between these cells and their adjacent sieve tube members via the plasmodesmata. Therefore, companion cells are adapted for their role as they contain many mitochondria that provide energy via cellular respiration.
Detailed explanation-2: -The companion cells are connected to the sieve tube elements via narrow channels called plasmodesmata, through which sugar molecules can be transported into and out of the sieve tube.
Detailed explanation-3: -Function of companion cell is to load sugar and amino acids into sieve elements. These cells use transmembrane proteins to take up these molecules by active transport.
Detailed explanation-4: -Companion cells showed a dense cytoplasm and various small vacuoles. They also revealed their characteristic large nucleus and abundant mitochondria.
Detailed explanation-5: -The companion cell actively transports hydrogen ions into the surrounding cells. This creates a hydrogen ion gradient between the surrounding cells and the companion cell. Hydrogen ions move back into the companion cell down their concentration gradient through a co-transporter protein.