Final answer:
To tell whether a cylindrical plant structure is a stem or root, examine its internal structure for features such as the arrangement of vascular tissue, presence of a root cap, and the proportion of cortex to pith.
Step-by-step explanation:
Identifying a Plant Structure as Stem or Root
To determine if a cylindrical structure cut from a plant is a piece of stem or a piece of root, we can examine the internal structure and look for specific features.
- Root Development: In a longitudinal section of a root, we would expect to see a meristem at the tip with small, actively dividing cells. As we move back, cells become larger and show features like secondary cell walls.
- A typical root cross-section includes dermal tissue, a cortex surrounding the endodermis, a pericycle just inside the endodermis, and a core of vascular tissue which could be a central pith or a solid core.
- Plant Stem Modifications: Stems may have nodes and internodes and can give rise to structures like rhizomes, stolons, and tubers, which have specific characteristics like the ability to give rise to new plants.
- Root Anatomy: Roots have a protective root cap exclusive to them, and their inner structure is different from stems, exhibiting a significant amount of cortex compared to pith.
Differences in vascular tissue arrangement, presence of a root cap, and the overall tissue structure can help distinguish whether the cylindrical structure is from a stem or root.