B3.2.17 (HL)—Root pressure generation
Root pressure is generated when active mineral ion transport into root xylem lowers water potential and water enters by osmosis.
- Syllabus
- First assessment 2025
- Objective
- B3.2.17
- Level
- HL
Exam analysis
Chance of appearing2%of analysed past papers
Latest appearanceNovember 2025
Most common paperPaper1
Typical marks1–2
Common command terms
- Identify
- Explain
Recent exam appearances
November 2025Paper2 ["HL"] · TZ34(b)(i)[ 2 ]B3.2.17 (HL)—Root pressure generation
May 2017Paper1 ["HL"] · TZ132[ 1 ]B3.2.17 (HL)—Root pressure generation
Practice this objective
Coverage 2017–2025 · Updated 15 Jul 2026
Concept essentials
- Active mineral ion transport into root xylem lowers xylem water potential.
- Water enters the xylem by osmosis in response to the solute gradient.
- The resulting positive pressure can push water upward.
- Root pressure is distinct from transpiration pull and capillary action.