Final answer:
All options provided—stolons, rhizomes, tubers, and corms—are stem adaptations used by plants for asexual reproduction and nutrient storage, not root adaptations.
Step-by-step explanation:
The structures listed—stolons, rhizomes, tubers, and corms—are all modifications of the stem, not the root. These stem adaptations serve as means for asexual reproduction and storage of nutrients, allowing plants to thrive in various environments.
- Stolons are stems that grow horizontally at or just below the soil surface and can give rise to new plants at their nodes.
- Rhizomes are horizontal underground stems that can produce vertical shoots from their nodes.
- Tubers, like the common potato, are enlarged structures at the ends of stolons that store starch and can give rise to new plants from their 'eyes' or adventitious buds.
- Corms are rounded, fleshy underground stems that store food, helping some plants survive winter and other harsh conditions.
Therefore, the correct answer to which of the following structures is a stem adaptation instead of a root adaptation is e. All are stem adaptations.