flowering plants

• What is photosynthesis?


  It is the process of making glucose from sunlight in the leaves of the plant.
• What type of reaction is photosynthesis?


  It is an endothermic reaction.
• What is the equation for photosynthesis?


  light + carbon dioxide + water → glucose + oxygen
• What are the chemical formulas for carbon dioxide, water, glucose, and oxygen?


  CO₂, H₂O, C₆H₁₂O₆, O₂
• What factors affect the rate of photosynthesis?


  • Temperature
  • Light intensity
  • Carbon dioxide concentration
• How does temperature affect the rate of photosynthesis?


  It increases the rate up to a certain point, after which enzymes denature.
• How does light intensity affect the rate of photosynthesis?


  Higher light intensity generally increases the rate of photosynthesis.
• What is the relationship between light intensity and distance from the light source?


  Light intensity is inversely proportional to the square of the distance.
• How does carbon dioxide concentration affect the rate of photosynthesis?


  As carbon dioxide concentration increases, the rate of reaction increases.
• What are the steps to investigate photosynthesis using water plants like Elodea?


  1. Set up a lamp with an LED bulb beside a beaker of water with the plant.
  2. Add sodium hydrogen carbonate to supply carbon dioxide.
  3. Observe the evolution of oxygen from the plant.
• What are the steps to investigate the effect of light intensity on photosynthesis?


  1. Place pondweed in water and set up a desk lamp.
  2. Move the lamp away by 10 cm.
  3. Leave for 5 minutes.
  4. Count bubbles produced in 1 minute.
  5. Repeat the steps.
• What are the steps to investigate the effect of carbon dioxide on photosynthesis?


  1. Use the same setup as the light intensity experiment.
  2. Instead of varying light intensity, use different concentrations of sodium hydrogen carbonate.
  3. Keep other variables constant.
• What are the steps to investigate starch production in a leaf?


  1. Cover half of a leaf with foil.
  2. Place the plant in sunlight for 48 hours.
  3. Boil the leaf to kill it.
  4. Soak in hot ethanol to remove chlorophyll.
  5. Dip in iodine solution.
  6. Observe color change: blue-black for starch, orange-brown for no starch.
• How does the experiment with a variegated leaf demonstrate the requirement of chlorophyll for photosynthesis?


  • Only green areas contain chlorophyll.
  • Only green areas will turn blue-black with iodine, indicating starch production.
  • White areas remain orange-brown, showing no starch production.
• What is the function of the waxy cuticle in leaves?


  It helps to reduce water loss by evaporation and is a protective layer.
• Why is the upper epidermis of a leaf thin and transparent?


  To allow light to enter the palisade mesophyll.
• What is the role of the palisade mesophyll in leaves?


  It contains lots of chloroplasts for rapid photosynthesis.
• How does the spongy mesophyll facilitate gas exchange?


  It has lots of air spaces to allow gases to diffuse in and out faster.
• What does the lower epidermis of a leaf contain?


  It contains guard cells and stomata.
• What is the function of guard cells in leaves?

  They open and close the stomata by absorbing or losing water.
• What happens to stomata during the day and night?


  Stomata open during the day and close at night.
• What is the role of magnesium in plants?


  It is required for chlorophyll production.
• What is the effect of magnesium deficiency in plants?


  It causes leaves to turn yellow.
• What is the role of nitrate in plants?


  It is required to produce amino acids.
• What happens to plants with nitrate deficiency?


  It causes stunted growth and turns leaves yellow.