In a plant, food is transported by phloem, while water and minerals are transported through xylem. The pressure-flow model in phloem is the main way food is transferred. The pressure-flow model contains elements called the source and the sink. The source is where the solution is more concentrated, while the sink is where the solution is less concentrated. Phloem transport is directional, and in the pressure-flow model, the solution flows from source to sink. Which means it flows from areas of higher concentration to areas of lower concentration. In the pressure-flow model, sucrose is actively transported into sieve tube members by osmosis. When this solution enters the sieve tube members, it causes a greater pressure potential at one end: the source. Because of this pressure, the entire solution of sucrose is pushed towards the sink end of the tube. In order for transport, the sieve plates must be...