Leaf Tissue

Below is a microscopic cross-section of a typical leaf (taken from a dicotyledonous plant)

  • Distribution of tissues may differ between different types of plants according to functional requirements

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Key Features:

  • Palisade mesophyll is the site of photosynthesis and hence is located on the upper surface of the leaf (facing sunlight)
  • Spongy mesophyll is the main site of gas exchange and is hence located on the lower surface of the leaf (near stomata)
  • Stomata are on the underside of the leaf (prevents obstruction so as to maintain an open channel for gas exchange)
  • The top surface of the leaf is covered by a thick, waxy cuticle (prevents water absorption which would affect transpiration)
  • Vascular bundles (including xylem and phloem) are located centrally to allow for optimal access by all leaf cells