Structure of a Leaf (WJEC GCSE Biology)

Revision Note

Naomi H

Author

Naomi H

Last updated

Structure of a Leaf

  • Leaves are plant organs; they are adapted to maximise the rate of photosynthesis

Leaf structure diagram

6l4hVohU_leaf-structure-diagram-biology-revision-notes

Leaf structure is adapted to maximise photosynthesis

Leaf structures & functions table

Structure Function
Cuticle A waxy layer that reduces evaporation from leaf surfaces
Epidermis A thin layer of cells that are transparent to allow light to reach photosynthesising cells
Palisade mesophyll layer A layer of palisade cells at the top of the leaf that contains many chloroplasts; these features maximise light absorption
Spongy layer Air spaces between cells allow the movement of gases
Xylem Transports water from the roots to the leaves
Phloem Transports the products of photosynthesis to the rest of the plant
Stomata Allow gases to move in and out of the leaf
Guard cells Can close to prevent excessive water loss in dry conditions

Stomata

  • Stomata (singular stoma) are pores on the underside of leaves that allow gas exchange
    • Photosynthesising cells need carbon dioxide for photosynthesis
    • Oxygen is released from photosynthesising leaves as a waste product
  • Stomata also allow water vapour to diffuse out of leaves, maintaining the upward movement of water in the xylem
  • Guard cells surround the stomata; when water availability is low the guard cells can cause the stomata to close, preventing loss of water vapour by transpiration

Stomata diagram

stomata

Stomata can close to reduce water loss 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.