The correct option is
B. Rhizomes.
Detailed Explanation:
- Definition of Rhizomes:
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Rhizomes are specialized underground stems that grow horizontally beneath the soil surface. They serve as a means of vegetative reproduction and storage for the plant. Rhizomes can produce new shoots and roots at nodes, allowing the plant to spread and colonize new areas.
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Function of Rhizomes:
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Rhizomes store nutrients and energy, which helps the plant survive adverse conditions (like drought or winter). They also allow for asexual reproduction, meaning that new plants can grow from the rhizome without the need for seeds. This is particularly advantageous for plants in competitive environments.
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Examples of Plants with Rhizomes:
- Common examples include ginger (Zingiber officinale), bamboo, and certain types of grasses. These plants can quickly spread through their rhizome systems, forming dense colonies.
Why the Other Options Are Incorrect:
- A. Bulbs:
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Bulbs are underground storage organs that consist of a short stem surrounded by fleshy leaves or scales. They grow vertically and are not horizontal like rhizomes. Examples include onions and tulips. Bulbs primarily store energy and nutrients for the plant to use during the growing season.
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C. Runners:
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Runners (or stolons) are horizontal stems that grow above the ground. They extend from the main plant and can root at nodes to form new plants. Examples include strawberries. While they also serve a similar purpose of vegetative reproduction, they do not grow underground like rhizomes.
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D. Corms:
- Corms are swollen underground stems that store nutrients, similar to bulbs, but they are solid and do not have the layered structure of bulbs. Corms grow vertically and are not horizontal like rhizomes. Examples include taro and crocus.
Summary of Key Points:
- Rhizomes are underground stems that grow horizontally and are crucial for vegetative reproduction and nutrient storage.
- Bulbs are vertical storage organs, while runners grow above ground and corms are solid, vertical storage structures.
- Understanding the differences between these structures is essential for identifying plant adaptations and reproductive strategies.
Revision Summary:
- Rhizomes are horizontal underground stems that allow for vegetative reproduction.
- Bulbs, runners, and corms serve different functions and structures in plants.
- Recognizing these differences helps in understanding plant biology and ecology.