Plant tissue

• Examples of plant tissue :

  1. Epidermal tissue- covers the whole plant
  2. Palisade metoprolol tissue- where most photosynthesis happens
  3. Spongy mesophyll tissue - big air space allow gas to diffuse in and out of cells
  4. Xylem and phloem - transport things around plant
  5. Meristem tissue - change into lots of different types of plant cells allow plant to grow
• What tissues does the leaf contain?

  Epidermal, mesophyll, xylem, and phloem tissues
• Epidermal tissues are covered with a waxy cuticle, help reduce water loss by evaporation
• Upper epidermis is transparent so light can pass through it to the palisade layer
• The palisade layer has lots of chloroplasts, this means that they’re near the top of the leaf where they can get the most light
• The xylem and phloem form a network of vascular bundles, which deliver water and other nutrients to entire leaf and take away glucose produced by photosynthesis. Also help support the structure
• The tissue of leaves are also adapted for efficient gas exchange

  • Lower epidermis full of holes called stomata, which let CO2 diffuse directly into leaf
• The opening and closing of stomata is controlled by guard cells
• Guard cells are sensitive to light and close at night to save water without losing out on photosynthesis
• When plant has lots of water, guard cells fill up and become turgid. this makes the stomata open so gasses can be exchanged
• When the plant is short of water. guard cells lose water and become flaccid, making the stomata close, helps stop too much water vapour escaping
• More stomata are on the underside of leaves than on the top. The lower surface is shaded and cooler so less water is lost through the stomata than if they were on the upper surface