Plant cell organisation

• What are the main organs of a plant?

  Stems, roots, and leaves
• How do plant organs work together?

  They form organ systems for survival and growth
• What is epidermal tissue in plants?

  It covers the whole plant
• What is the role of spongy mesophyll tissue?

  It allows gases to diffuse in and out
• What is the function of palisade mesophyll tissue?

  It is where most photosynthesis occurs
• What do xylem and phloem transport?

  Water, mineral ions, and food
• What is meristem tissue responsible for?

  It allows the plant to grow by differentiating
• What tissues make up a leaf?

  Epidermal, mesophyll, xylem, and phloem
• How does the waxy cuticle benefit the leaf?

  It reduces water loss by evaporation
• Why is the upper epidermis transparent?

  To allow light to pass to the palisade layer
• Why are chloroplasts abundant in the palisade layer?

  To maximize light absorption for photosynthesis
• What is the function of vascular bundles in leaves?

  To deliver water and nutrients and support structure
• How do stomata facilitate gas exchange?

  They allow CO₂ to diffuse into the leaf
• What controls the opening and closing of stomata?

  Guard cells respond to environmental conditions
• What is transpiration?

  Loss of water from the plant's surface
• What causes transpiration to occur?

  Evaporation and diffusion of water
• What is the transpiration stream?

  Movement of water from roots to leaves
• How does light intensity affect transpiration?

  Brighter light increases transpiration rate
• How does temperature influence transpiration?

  Warmer temperatures increase transpiration rate
• What effect does air flow have on transpiration?

  Faster air flow increases transpiration rate
• How does humidity affect transpiration?

  Drier air increases transpiration rate
• How can transpiration rate be estimated?

  By measuring water uptake by the plant
• What is the structure of phloem tubes?

  Columns of living cells with small pores
• What is the function of phloem tubes?

  To transport food substances throughout the plant
• What happens to guard cells when the plant has lots of water?

  They become turgid and open the stomata
• What is the structure of xylem tubes?

  Made of dead cells with no end walls
• What is the function of xylem tubes?

  To carry water and mineral ions from roots
• How do guard cells function?

  They open and close stomata to regulate gas exchange
• What happens to guard cells when the plant is short of water?

  They lose water and close the stomata
• Why do guard cells have a kidney shape?

  To effectively open and close the stomata
• Why are there more stomata on the underside of leaves?

  To reduce water loss in shaded areas
• How do different leaves vary in stomata distribution?

  They adapt to their environmental conditions
• What is the relationship between transpiration and photosynthesis?

  Transpiration is a side-effect of photosynthesis
• What is the role of root hair cells in plants?

  They are adapted for efficient diffusion of water
• What is the significance of measuring transpiration rate?

  It indicates water loss from the leaves
• What is the effect of light on stomata behavior?

  Stomata close at night to save water
• How does temperature affect guard cell function?

  Higher temperatures increase guard cell turgidity
• What is the role of lignin in xylem tubes?

  It strengthens the xylem structure
• What is the main purpose of transpiration?

  To maintain water movement through the plant
• What are the adaptations of guard cells for their function?

  • Kidney shape for opening and closing stomata
  • Turgidity changes with water levels
  • Thin outer walls and thickened inner walls
  • Sensitive to light, closing at night