plant cell organisation

• What is meristem tissue and where is it found?

  Meristem tissue is made up of plant stem cells. It's found in the growing parts of plants such as the tips of roots and shoots
• What is a stomata?

  Tiny holes in leaves that allow for carbon dioxide to diffuse in from the air for photosynthesis
• What is a phloem?

  Plant tissue responsible for transporting cell sap and sugars up and down the plant (e.g. sugar molecules produced by photosynthesis can be transported to the rest of the plant)
• What is a xylem?

  Plant tissue that transports water and nutrients from the roots to the rest of the plant by active transport
• What is the function of the waxy cuticle on leaves?

  It prevents water loss from the leaf
• How do guard cells respond when there is enough water in the leaf?

  They become turgid and keep stomata open so that carbon dioxide can diffuse into the leaf
• What happens to guard cells when the leaf is short of water?

  They become flaccid and close the stomata to conserve water vapour
• Why do guard cells close at night?

  Because photosynthesis isn't taking place
• Why are stomata primarily located on the underside of the leaf?

  It is cooler and reduces water evaporation
• What are the adaptations of leaves to minimize water loss?

  • Waxy cuticle prevents water loss
  • Guard cells regulate stomata based on water availability
  • Stomata mostly on the underside to reduce evaporation
• Where in the plant is glucose produced?

  The leaves
• What is the movement of cell sap (mixture of sugar and water) up and down the plant called?

  Translocation
• What are the pores in phloem cells for?

  Allowing cell sap to pass along the phloem tube
• How do root hair cells absorb water and mineral ions from the soil?

  Water - osmosis

  Mineral ions - active transport
• What substance are xylem cells reinforced with to make them stronger?

  Lignin
• What is transpiration?

  The evaporation of water from the leaves
• What are the factors affecting the rate of transpiration?

  • Light intensity - brighter light means more photosynthesis so the stomata will be open and water will leave the leaf
  • Temperature - higher temperature increases the rate because the water particles have more energy
  • Air flow - higher air flow means a higher rate because the concentration gradient will remain high
  • Humidity - more humidity means lower rate because the concentration gradient is lower