Describe how water moves from the soil into a plant and up to the leaves.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
Model answer (4 marks)
Water enters root hairs by osmosis.
Water moves through the cortex towards the xylem.
In the xylem, water travels up the stem.
Evaporation of water from leaf stomata (transpiration) creates a pull that draws water upward.
Water moves through the cortex towards the xylem.
In the xylem, water travels up the stem.
Evaporation of water from leaf stomata (transpiration) creates a pull that draws water upward.
Examiner tips
- Use the word "osmosis" for entry into root hairs. Mention the xylem as the transport tissue. Explain that transpiration creates tension to pull water up. Keep the answer concise and use correct terminology.
Common mistakes
- Forgetting to mention osmosis. Using "capillary action" instead of transpiration. Describing water movement in the wrong direction or omitting the xylem.
Mark scheme (4 marks)
- Water enters root hair cells by osmosis
- Water moves across the root (cortex) towards the xylem
- Water travels up the stem in xylem vessels
- Water evaporates from leaves (transpiration) creating a pull / tension that draws water upwards
Related
- All WJEC GCSE Biology (Wales) revision notes →
- How to answer a "Describe" question →
- Decode the mark scheme abbreviations →
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