Plant anatomy — radial vascular bundles: Identify the arrangement that defines a radial vascular bundle. In this bundle type (typical of roots), xylem and phloem occur on separate, alternating radii rather than together in the same strand. Choose the correct description.
General Knowledge
Biology
Difficulty: Easy
Choose an option
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AXylem and phloem lie together on the same radius (conjoint arrangement)
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BXylem is external and phloem internal (amphicribral)
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CXylem and phloem occur on different, alternating radii (typical of roots) — radial
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DPhloem completely surrounds xylem (bicollateral)
Answer
Correct Answer: Xylem and phloem occur on different, alternating radii (typical of roots) — radial
Explanation
Given data
- Asked: definition of radial vascular bundle.
- Context: classification of vascular bundle arrangements.
Concept / ApproachIn radial bundles, xylem and phloem are in separate strands arranged on alternate radii of the organ. This is characteristic of roots. By contrast, in conjoint bundles (typical of stems/leaves), xylem and phloem lie together on the same radius.
EliminationOptions describing conjoint, amphicribral, or bicollateral arrangements do not match the root-type alternating pattern.
Final AnswerXylem and phloem occur on different, alternating radii (radial).