Transport of Water in Plants (WJEC GCSE Biology)

Revision Note

Naomi H

Author

Naomi H

Last updated

Xylem & the Transport of Water

The role of xylem

  • Xylem cells form tubes that carry water and dissolved mineral salts in plants
  • Water is transported from the roots, through the stem and into the leaves
    • Here it is either used in photosynthesis or lost in transpiration
  • Xylem vessels are adapted to allow water to move easily from the roots to the leaves, e.g.
    • They are dead cells, meaning that they are hollow and water can flow through them easily
    • They have no end walls to slow the flow of water

The role of transpiration

  • Transpiration can be defined as

The loss of water vapour by evaporation from the leaves of plants

  • Water evaporates from the surface of cells that line the air spaces inside leaves before exiting by diffusion
    • Water diffuses out via the stomata
  • More water is drawn up the xylem to replace the water that is lost in transpiration, ensuring a continuous stream of water inside the xylem
    • This upward movement of water is known as the transpiration stream
  • This supplies water to leaf cells for photosynthesis, as well as bringing dissolved minerals from the soil

Transpiration diagram

transpiration

Water travels from the roots to the rest of the plant in the xylem before it is lost at the leaves by transpiration

You've read 0 of your 10 free revision notes

Unlock more, it's free!

Join the 100,000+ Students that ❤️ Save My Exams

the (exam) results speak for themselves:

Did this page help you?

Naomi H

Author: Naomi H

Expertise: Biology

Naomi graduated from the University of Oxford with a degree in Biological Sciences. She has 8 years of classroom experience teaching Key Stage 3 up to A-Level biology, and is currently a tutor and A-Level examiner. Naomi especially enjoys creating resources that enable students to build a solid understanding of subject content, while also connecting their knowledge with biology’s exciting, real-world applications.