Final answer:
The model's advantage is that it clearly illustrates the general movement directions of substances within a plant, highlighting the roles of xylem and phloem in the vascular system.
Step-by-step explanation:
An advantage of using the model of the transportation systems in a plant is that it clearly shows the general directions that food, water, and minerals must move. This model aids in visualizing the basic functions of the plant's vascular system, which consists of xylem and phloem tissues. The xylem primarily moves water and minerals absorbed from the roots upwards to the rest of the plant, while the phloem transports sugars produced by the leaves to various parts, including the roots. By focusing on the directionality of substance movement, the model can make the concept more understandable for students.