Plant Cells Organisation

• Photosynthesis

  Takes place in leaves
• Meristem tissue


  • Found in growing tips like shoots and roots, contains stem cells that can differentiate into different plant tissues
• Spongy mesophyll

  • Full of air spaces allowing for diffusion of gases like carbon dioxide and oxygen between stomata and palisade cells
• Stomata


  • Allow carbon dioxide to enter the leaf and oxygen to leave, help control water vapor passing out of the leaf
• different tissues in a plant

  • Epidermal tissue
  • Palisade mesophyll
  • Spongy mesophyll
  • Xylem
  • Phloem
  • Meristem tissue
• Guard cells


  • Found on either side of stomata, help regulate the opening and closing of stomata
• Xylem tissue


  • Transports water from roots to stem and leaves, transports dissolved mineral ions like magnesium for chlorophyll production
• Phloem tissue


  • Transports dissolved sugars produced by photosynthesis from leaves to the rest of the plant, sugars can be used immediately or stored as starch, movement of sugars is called translocation
• Epidermal tissue


  • Consists of epidermal cells, upper epidermis is transparent allowing light to pass through, lower epidermis has stomata for gas exchange (CO2 enters and 02 leaves), upper epidermis has waxy cuticle to reduce water evaporation
• Palisade mesophyll

  • Consists of palisade cells packed full of chloroplasts containing chlorophyll for photosynthesis
• The rate of transpiration is faster in higher temperatures because the rate of evaporation is faster
• transpiration is quicker under dry conditions because the rate of evaporation is faster
• transpiration is quicker under windy conditions as water is removed from the top of the leaf allowing evaporation to occur quicker
• Transpiration is quicker under sunny conditions because more photosynthesis occurs meaning the stomata open up to allow carbon dioxide in