plant tissues

• the top and bottom of the leaf are covered with a layer of very thin cells called the epidermis cells that form epidermis tissue
• the role of the epidermis?

  protects the surface of the leaf
• feature of the upper epidermis

  • transparent= allows light to pass through to the photosynthetic cells below
  • covered with a thin layer of oily material= waxy cuticle
• what is the purpose of the waxy cuticle?

  reduces the evaporation of water from the surface of the leaf

  = helps prevent leaf from drying out
• what are the tiny pores called in the lower epidermis?

  stomata
• role of the stomata?

  allows CO2 to enter the leaf and O2 to leave

  helps control the amount of WV that can pass out of the leaf
• whats on the sides of the stomata?

  guard cells
• the palisade mesophyll consists of palisade cells
• palisade cells are packed full of chloroplasts that contains chlorophyll which absorbs light energy needed for photosynthesis
• what is the spongy mesophyll full of?

  air spaces
• what is the purpose of the air spaces?

  allows CO2 to diffuse from the stomata through the spongy mesophyll to the palisade cell
• oxygen diffuses from the palisade cells through the spongy mesophyll to the stomata
• role of xylem in plant tissues:

  • transports water from the roots to the stem and leaves

  = some water is used in photosynthesis

  • transports dissolved mineral ions (Mg= used to make chlorophyll)
• role of phloem in plant tissues:

  • transports dissolved sugars produced by photosynthesis from the leaves to the rest of the plant

  = sugars can be used for glucose in respiration

  = then can be stored as starch
• whats translocation?


  Movement of sugars and other molecules through phloem tissue
• where is meristem located?

  growing tips (shoots and roots)
• what does meristem tissue contain?

  stem cells which can differentiate into different types of plant tissue
• meristems are important because they allow plants to grow continuously throughout their life cycle.
• what is the order of plant tissues in plant cells?

  waxy cuticle, upper epidermis, chloroplasts, palisade mesophyll, spongy mesophyll, air space, stomata + guard cells, lower epidermis