The contents of the phloem always move down the stem of the plant.

Question

Quizplus · Accepted Answer

The pressure-flow model of phloem transport can account for any direction of flow in sieve tubes if we consider that the direction of flow is always from source to sink.In other words,phloem contents can move either up or down as appropriate for the plant at a particular time in its life cycle.For example,recently formed leaves can be a sink,and they will receive sucrose until they begin to photosynthesize maximally.

The Contents of the Phloem Always Move Down the Stem