Plant tissues organs systems

• What are the three main organ systems in plants?

  Stems, roots, and leaves
• What is the function of plant organs?


  To transport substances and support plant growth
• What are examples of plant organs and their corresponding tissues?

  • Epidermal tissue: covers the whole plant
  • Palisade mesophyll tissue: site of photosynthesis
  • Spongy mesophyll tissue: allows gas diffusion
  • Xylem: transports water and minerals
  • Phloem: transports food
  • Meristem tissue: allows growth and differentiation
• What is the role of the upper epidermis in a leaf?


  It is transparent to allow light to pass to the palisade layer
• What is the function of the palisade layer in a leaf?


  It contains many chloroplasts for photosynthesis
• What is the purpose of vascular bundles in a leaf?


  To deliver water and nutrients and support the leaf structure
• What are stomata and their function?


  Stomata are openings that allow CO₂ to diffuse into the leaf
• How do guard cells regulate the opening and closing of stomata?


  They change shape based on water availability
• What is transpiration and its significance in plants?


  • Transpiration is the loss of water vapor from plant leaves.
  • It helps in nutrient transport and cooling the plant.
  • It creates a transpiration stream that pulls water from roots to leaves.
• What are phloem tubes made of?


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


  To transport food, mainly dissolved sugars, throughout the plant
• What is translocation in plants?


  It is the process of transporting food in both directions through phloem
• What are xylem tubes made of?


  Dead cells joined end to end, strengthened with lignin
• What is the main function of xylem tubes?


  To carry water and minerals from roots to stems and leaves
• What causes the transpiration stream in plants?


  It is caused by evaporation of water from leaves
• How does light intensity affect the rate of transpiration?


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


  Higher temperatures increase the rate of evaporation
• How does air flow affect transpiration rates?


  Better air flow increases the transpiration rate
• How does humidity affect the rate of transpiration?


  Higher humidity decreases the rate of transpiration
• What is the role of guard cells in transpiration?


  They control the opening and closing of stomata to regulate water loss
• What shape are guard cells and why?


  They are kidney-shaped to open and close stomata
• What happens to guard cells when a plant has lots of water?


  They become turgid and open the stomata
• What happens to guard cells when a plant is short of water?


  They lose water and close the stomata
• How are guard cells adapted for gas exchange?


  They have thin outer walls and thickened inner walls for effective opening and closing
• Where are most stomata located on a leaf and why?


  On the underside to reduce water loss and provide shade