WebbTerms in this set (20) Describe the mass flow hypothesis for the mechanism of translocation in plants (4 marks) In source/leaf sugars actively transported into phloem. … WebbMass-flow hypotheses include the pressure-flow hypothesis, which states that flow into sieve tubes at source regions (places of photosynthesis or mobilization and exportation of storage products) raises the osmotic pressure in the sieve tube; removal of sugars from sieve tubes in sink regions—i.e., those in which sugars are removed or imported …

14.6 Pressure Flow Theory Mechanism of Phloem Transport

WebbThe movement of phloem cells is bidirectional; however, the movement of xylem cells is unidirectional (upward). For this multi-directional flow, as well as the fact that sap … WebbImage showing the setup of a tracer and ringing experiment. The leaves have been enclosed to ensure the uptake of radioactive carbon dioxide. The results from the experiment show that: The phloem is involved in the transport of sucrose. There is no radioactive sucrose detected past the ringing point on the stems (where the phloem has … rcs/test

Phloem transport: a review of mechanisms and controls

WebbAs a fundamental tissue in the plant body, phloem functions extend from its primary process of transporting sugar to include transporting signalling molecules like mRNAs, hormones, defences from biotic and abiotic agents, sustenance for the organs, gas exchange, and storage of numerous waste products, including starch, calcium oxalate … Webb#pressureFlowTheory#PressureFlowHypothesis #PressureFlowMechanism#PhloemTransport#pressureflowtheory1styearbiology#pressureflow-massflowhypothesis#FSCbiology... WebbEstimation of the phloem resistance indicates that a point might be reached in long sieve tubes where the pressure required to drive the Münch flow cannot be generated. … rc stewart finney md