Plant structures and their functions

• What are the main producers of food in ecosystems?

  Plants and algae
• What process do plants use to synthesize food from sunlight?

  Photosynthesis
• What type of reaction is photosynthesis?

  Endothermic reaction
• Where does photosynthesis occur in plants?

  In chloroplasts
• What is the equation for photosynthesis?

  Light + CO₂ + H₂O → C₆H₁₂O₆ + O₂
• What is the chemical symbol for carbon dioxide?

  CO₂
• What is the chemical symbol for glucose?

  C₆H₁₂O₆
• What is a limiting factor in photosynthesis?

  An environmental condition restricting photosynthesis rate
• How does temperature affect the rate of photosynthesis?

  Increases until enzymes denature
• What happens to the rate of photosynthesis as light intensity increases?

  It generally increases
• How does carbon dioxide concentration affect photosynthesis?

  Higher concentration increases the rate

  
• What is the significance of a graph leveling off in photosynthesis studies?

  Indicates a limiting factor is reached
• What is the purpose of measuring oxygen production in photosynthesis experiments?

  To calculate the rate of photosynthesis
• What is the setup for measuring the rate of photosynthesis using pondweed?

  Pondweed in water with a lamp and syringe
• Why is it important to control variables in a photosynthesis experiment?

  To ensure a valid experiment
• What unit is light intensity measured in?

  Lux
• What does the inverse square law state about light intensity?

  It decreases with the square of the distance
• If a lamp is 2 meters away, what is the light intensity compared to its original value?

  It is a quarter of the original value
• What are the adaptations of root hair cells?

  • Large surface area for water uptake
  • Large permanent vacuole for water movement
  • Mitochondria for energy in active transport
• What are the adaptations of xylem cells?

  • Lignin makes cells hollow and strong
  • Cells die to form continuous tubes
  • Lignin spirals withstand water pressure
• What are the adaptations of phloem cells?

  • Sieve plates allow substance movement
  • Cells are alive and functional
  • Companion cells provide energy for transport
• What is transpiration?

  Loss of water vapor from plants
• How does transpiration occur in plants?

  Water evaporates through open stomata
• What role do guard cells play in transpiration?

  They open and close stomata
• Why are more stomata found on the bottom of leaves?

  To minimize water loss by evaporation
• What is translocation in plants?

  Movement of food substances in phloem
• Where does translocation occur in plants?

  Only in the phloem
• What are sources and sinks in translocation?

  Sources are where food is made, sinks are where used
• How can the location of sources and sinks change?

  They can depend on the season
• What are the adaptations of leaves for specific functions?

  Stomata, chlorophyll, thinness, large surface area
• What is the function of stomata in leaves?

  They allow gas exchange and control water loss
• Why is chlorophyll green?

  It is the most efficient color for absorbing light
• How does the thinness of leaves benefit photosynthesis?

  It shortens the distance for gas diffusion
• What advantage does a large surface area provide for leaves?

  It maximizes light absorption for photosynthesis
• What factors affect the rate of water uptake and transpiration?

  Temperature, humidity, air movement, light intensity
• How does an increase in temperature affect transpiration?

  It increases evaporation and transpiration rates
• What happens to transpiration when relative humidity increases?

  It decreases due to a reduced concentration gradient
• How does increased air movement affect transpiration?

  It increases transpiration by lowering water vapor concentration
• What is the effect of increased light intensity on transpiration?

  It increases transpiration by opening more stomata
• How is the rate of transpiration measured using a potometer?

  By measuring the distance a bubble travels in a capillary tube