B3.2.9—Stem tissue distribution
Dicot stems arrange vascular bundles in a ring, with xylem, phloem, cambium and supporting tissues positioned for transport and support.
- Syllabus
- First assessment 2025
- Objective
- B3.2.9
- Level
- SL
Concept essentials
- Dicot stem vascular bundles are arranged in a ring.
- Xylem is usually nearer the centre of each bundle, with phloem toward the outside.
- Phloem is the tissue responsible for sucrose translocation.
- Plan diagrams emphasise tissue positions rather than individual cells.
ConceptIB Biology SL