Transpiration and stomata

    Cards (20)

    • What is the main topic discussed in the study material?
      Transpiration
    • What are the four main factors that affect the transpiration rate?
      1. Light Intensity
      2. Temperature
      3. Air Flow
      4. Humidity
    • How does light intensity affect the transpiration rate?
      The brighter the light, the greater the transpiration rate.
    • What happens to stomata as it gets darker?
      Stomata begin to close as it gets darker.
    • Why do stomata close in the dark?
      Photosynthesis can't happen in the dark, so they don't need to be open to let CO₂ in.
    • How does temperature affect transpiration?
      The warmer it is, the faster transpiration happens.
    • Why does transpiration increase with temperature?
      Water particles have more energy to evaporate and diffuse out of the stomata when it's warm.
    • How does air flow affect transpiration rate?
      The better the air flow around a leaf, the greater the transpiration rate.
    • What happens to water vapor if air flow around a leaf is poor?
      The water vapor surrounds the leaf and doesn't move away, leading to a high concentration of water particles outside the leaf.
    • How does humidity affect transpiration?
      The drier the air around a leaf, the faster transpiration happens.
    • Why does transpiration happen faster in dry air?
      There is a greater difference in concentration between the inside and outside of the leaf.
    • How can you estimate the rate of transpiration in a plant?
      • Measure the uptake of water by the plant.
      • Water uptake is directly related to water loss by the leaves (transpiration).
    • What apparatus is used to measure transpiration rate?
      A potometer is used to measure the rate of transpiration.
    • What should be kept constant during the transpiration experiment?
      The temperature and humidity conditions should be kept constant.
    • How are guard cells adapted to open and close stomata?
      • Kidney shape allows for opening and closing.
      • Fill with water to become turgid and open stomata.
      • Lose water to become flaccid and close stomata.
      • Thin outer walls and thickened inner walls facilitate movement.
      • Sensitive to light, closing at night to save water.
    • Where are stomata usually found in greater numbers on a leaf?
      On the undersides of leaves.
    • Why are there usually more stomata on the underside of leaves?
      The lower surface is shaded and cooler, reducing water loss.
    • How can different leaves be compared for stomata distribution?
      • Peel the epidermal tissue off some leaves.
      • Mount them on microscope slides for observation.
    • Which plant is likely to have fewer stomata per cm² on the underside of its leaves: Aloe vera or primroses?
      Aloe vera is likely to have fewer stomata due to its adaptation to hot, dry areas.
    • Why might Aloe vera plants have fewer stomata compared to primroses?
      Aloe vera plants are adapted to conserve water in hot, dry areas.