Which one of the following statements about transport of nutrients in phloem is false?
a) Differences in osmotic concentration at the source and sink cause a hydrostatic pressure gradient to be formed.
b) Companion cells control the rate and direction of movement of phloem sap.
c) A sink may be located anywhere in the plant.
d) A sink is that part of the plant where a particular solute is consumed or stored.
e) Solute particles can be actively transported into phloem at the source.
Ans: b) Companion cells control the rate and direction of movement of phloem sap.
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