What is the primary function of the tubes found in stems?

The primary function of the tubes found in stems is to transport food and water throughout the plant. In vascular plants, two main types of tubes are responsible for this transportation: xylem and phloem. Xylem tubes carry water and dissolved minerals absorbed from the soil up from the roots to the leaves, where photosynthesis occurs. On the other hand, phloem tubes transport the sugars and nutrients produced during photosynthesis from the leaves to other parts of the plant, including roots, stems, and fruits, where they are needed for growth and development. This transport system is crucial for maintaining the plant's health, as it ensures that all parts of the plant receive the necessary resources to thrive.

While the structural support of the stem is important, and the plant can have adaptive features to store nutrients and defend against herbivores, the primary role of the vascular tubes remains focused on the essential processes of water and nutrient transportation.