organisation in plants

• What is the primary function of leaves?

  Photosynthesis
• Why are leaves considered organs?

  They contain many tissues working together
• What is the function of the waxy cuticle on leaves?

  Makes the leaf waterproof
• What is the role of the upper epidermis in leaves?

  Protects against water loss and allows light in
• What type of cells are found in the palisade mesophyll?

  Tightly packed cells with chloroplasts
• Why do palisade mesophyll cells have many chloroplasts?

  To absorb light for photosynthesis
• What is the structure of spongy mesophyll cells?

  Spherical cells with air spaces
• How do spongy mesophyll cells facilitate gas exchange?

  They have air spaces for quick diffusion
• What are stomata?

  Tiny openings on the leaf's surface
• What is the function of guard cells?

  Control the opening and closing of stomata
• How do guard cells respond when a plant has plenty of water?

  They become turgid and open the stomata
• What is transpiration?

  Water loss through stomata by evaporation
• What is the transpiration stream?

  Constant movement of water up the plant
• What are the functions of transpiration in plants?

  • Keeps cells turgid
  • Provides water for photosynthesis
  • Transports mineral ions
• What is translocation in plants?

  Movement of dissolved sugars from leaves
• Why is translocation important for plants?

  It allows for respiration, growth, and storage
• What factors affect the rate of transpiration?

  • Temperature
  • Humidity
  • Wind speed
  • Light intensity
• How does temperature affect transpiration rate?

  Higher temperatures increase evaporation rate
• How does humidity influence transpiration?

  Lower humidity increases transpiration rate
• What effect does wind speed have on transpiration?

  More wind increases transpiration rate
• How does light intensity affect transpiration?

  Higher light intensity opens stomata wider
• What is the role of root hair cells?

  Increase absorption of water and minerals
• How do root hair cells increase absorption?

  By increasing the root surface area
• Why do root hair cells contain many mitochondria?

  To transfer energy for active transport