B3.2.8—Xylem vessel adaptations
Xylem vessels are dead, hollow, lignified tubes with absent end walls and pits, supporting efficient water transport and plant structure.
- Syllabus
- First assessment 2025
- Objective
- B3.2.8
- Level
- HL
Exam analysis
Chance of appearing3%of analysed past papers
Latest appearanceNovember 2025
Most common paperPaper2
Typical marks2–3
Common command terms
- Identify
- Outline
Scoring notes
- Common mistake
- Saying xylem is dead without explaining how lack of contents reduces resistance.
Recent exam appearances
November 2025Paper1B ["HL"] · TZ32(f)[ 3 ]B3.2.8—Xylem vessel adaptations
May 2025Paper2 ["HL"] · TZ24(a)[ 2 ]B3.2.8—Xylem vessel adaptations
May 2019Paper2 ["HL"] · TZ14(a)[ 2 ]B3.2.8—Xylem vessel adaptations
Practice this objective
Coverage 2019–2025 · Updated 15 Jul 2026
Concept essentials
- Xylem vessels lack cell contents, so water flow is less obstructed.
- Absent or perforated end walls create long transport tubes.
- Lignified walls provide support and resist collapse under tension.
- Pits allow lateral movement of water and minerals.