Evaluating Data Linked to Mass Flow Hypothesis

Question 1

The mechanism of transport that occurs within the phloem is still debated by scientists
The mass flow hypothesis suggests that there

Answer 1

is a translocation of sucrose and other sugars within the phloem occur via a continuous unidirectional flow of water and dissolved nutrients

The direction of flow is from the source (where sugars are produced) to the sink (where sugars are respired)

Question 2

If the mass flow hypothesis is correct then in any one sieve tube there should be a

Answer 2

bulk flow of phloem sap in one direction, travelling at the same rate. This should also be occurring at the same time in most sieve tube elements.