Plant tissue

• By the end of this video you should be able to describe the roles of the different tissues in a plant
• Photosynthesis takes place in leaves
• Leaf

  A plant organ
• Leaf


  • Contains different tissues
• This diagram shows a cross section of a leaf
• Epidermal cells


  Form epidermal tissue
• Upper epidermis

  Covers the top of the leaf
• Lower epidermis

  Covers the bottom of the leaf
• Epidermis


  • Protects the surface of the leaf
• Upper epidermis

  • Transparent to allow light to pass through
• Waxy cuticle

  Thin layer of oily material covering the upper epidermis
• Waxy cuticle

  • Reduces evaporation of water from the leaf surface
• Stomata

  Tiny pores in the lower epidermis
• Stomata

  • Allow carbon dioxide to enter and oxygen to leave the leaf
• Guard cells


  Found on either side of the stomata
• Palisade mesophyll

  Cells packed full of chloroplasts
• Spongy mesophyll

  Full of air spaces
• Spongy mesophyll

  • Allows carbon dioxide to diffuse to the palisade cells and oxygen to diffuse out
• Xylem

  Transports water and dissolved mineral ions from roots to stem and leaves
• Phloem

  Transports dissolved sugars produced by photosynthesis from leaves to rest of plant
• Translocation

  Movement of sugars through phloem tissue
• Meristem tissue


  Contains stem cells that can differentiate into different plant tissues
• Meristem tissue is found at growing tips of shoots and roots