Question

The translocation of organic solutes in sieve tube members is supported by

• A. root pressure and transpiration pull
• B. P proteins
• C. mass-flow involving carrier and ATP
• D. cytoplasmic streaming

Answer 1

The correct option is C mass-flow involving carrier and ATP

According to the mass flow hypothesis, the transport of organic solutes takes place from source to sink. The organic solutes are loaded on to phloem at the source and taken off from the phloem at the sink by active transport, which involves carriers. Root pressure and transpirational pull are involved in the transport of water. Cytoplasmic streaming is involved in the symplast pathway of water transport.