plant cell organisation

• The root, stem, and leaves, together make up an organ system
• waxy cuticle: layers of wax on the leaf surface to prevent water loss

  
• upper epidermis: helps protect the leaf by aiding in preventing water loss and providing an extra layer between the outside and the inside of the leaf

  
• Palisade mesophyll layer: contains chloroplasts and is the site of photosynthesis

  
• Spongy mesophyll layer: contains lots of air spaces for better diffusion of gases in and out the cell and is the site of photosynthesis

  
• Lower epidermis: is the outermost layer of the leaf and contains chloroplasts

  
• guard cells: help to regulate the rate of transpiration by opening and closing the stomata

  
• stomata: tiny openings or pores that enable gaseous exchange

  
• At night time, when photosynthesis can't take place, are the stomata normally open or closed:

  • closed