Photosynthesis Practical

• What type of variable is light intensity in this photosynthesis experiment?

  Independent variable
• What is the dependent variable in this photosynthesis experiment?

  Rate of photosynthesis
• How is the rate of photosynthesis measured in this experiment?

  Number of bubbles produced in a minute
• What equipment is mentioned to move to change light intensity?

  Move lamp
• What are the control variables in this photosynthesis experiment?

  • Concentration of carbon dioxide
  • Temperature
  • Type of plant
• What type of lamp is mentioned in the experimental setup?

  Desk lamp
• How is light intensity related to the distance in this experiment?

  Inversely proportional to the square of the distance
• What is the relationship between light intensity (I) and distance (d)?

  $I \propto 1/d^2$
• What are the steps in the method of this photosynthesis experiment?

  1. Place pond weed in a beaker of water, ensuring the stem is submerged.
  2. Add a small quantity of sodium hydrogen carbonate to supply carbon dioxide.
  3. Start with the lamp 10cm from the pond weed and count the number of bubbles coming out of the stem for one minute.
  4. Repeat this twice more to get three sets of results.
  5. Move the light 10cm further away from the beaker and repeat steps 3 and 4.
  6. Repeat this process for a number of distances.
• What chemical is added to the water to supply carbon dioxide?

  Sodium hydrogen carbonate
• How many times should the bubble count be repeated at each distance?

  Three times
• What is the initial distance between the lamp and the pond weed in the described method?

  10cm
• In the experiment, why is it important to ensure the stem of the pond weed is submerged?

  To observe bubbles being produced
• Why is it important to repeat the bubble count multiple times in this experiment?

  To obtain reliable results