The Mass Flow Hypothesis explains the movement of sugars in plants. This movement is primarily from:
Sink to source
Root to leaves only
Leaves to root only
Source to sink
Related Questions
Which of the following mechanism can explain the transport of sucrose from source to sink?
    Osmotic movement of water into sugar loaded sieve tube cells which create a higher hydrostatic pressure into the source than in the sink
Tension created by differences in pressure potential between source and sink
    Active absorption of sucrose through sieve tube membrane driven by a specific pump
    Transpiration and active transport of sugar from source to sink
Which observation in the Girdling Experiment confirms the role of phloem in downward transport?
Swelling of the region above the girdle
Wilting of leaves below the girdle
Increased root growth
No change in stem thickness
    When sugars enter sieve tubes, water flows by osmosis, resulting in
    Water potential
Osmotic gradient
Turgor pressure
DPD
Imagine a hypothetical plant where sucrose transporters in companion cells are genetically modified to actively transport sucrose out of sieve tubes near the source. Assuming all other aspects of phloem structure and function remain the same, what would be the MOST likely effect on translocation according to the mass flow hypothesis?
Translocation would proceed normally, as the pressure gradient is independent of companion cell activity.
Translocation would be enhanced, as sucrose would be actively removed from the sieve tubes, creating a stronger sink.
Translocation would be significantly reduced or stopped, as the pressure gradient would be reversed or eliminated.
The direction of translocation would be reversed, with flow occurring from sink to source.
If the mass flow hypothesis were entirely accurate, which scenario would be LEAST likely to occur in a plant?
Movement of sucrose from a leaf to a developing fruit.
Higher turgor pressure in phloem sieve tubes near a photosynthesizing leaf compared to those near a root tip.
Simultaneous bidirectional transport of different organic molecules within the same sieve tube element.
Changes in phloem sap composition based on the source and sink tissues involved.
Sugar stored in roots may be mobilised to become a source of food in the
    Winters
Early spring
Summers
Early summers
The Girdling Experiment demonstrates that the transport of organic nutrients in plants occurs through which vascular tissue?
Phloem
Xylem
Cambium
Pith
Which tissue is primarily involved in the transport of sugars as explained by the Mass Flow Hypothesis?
Xylem
Phloem
Cambium
Cortex
Which of the following is NOT a requirement for the mass flow hypothesis to function?
Presence of living phloem cells
A pressure gradient between source and sink
Active transport of sugars into phloem at the source
Active transport of water into phloem at the sink
    Which of the following is appropriate for mass-flow hypothesis?
    Transpiration pull is responsible for absorption of ions
    Large amount of ions are also absorbed along with the absorption of water
    As suction pressure increases, absorption of water increases and along with water, absorption of ion also increases
    All of the above
