REQUIRED PRACTICAL PHOTOSYNTHESIS

• What is the first step in the practical investigation of light intensity on photosynthesis?


  • Take a boiling tube
  • Place it 10 centimeters away from an LED light source
• Why is an LED light used in the experiment?


  Because it doesn't release much heat
• What does sodium hydrogen carbonate solution release?


  Carbon dioxide
• Why is carbon dioxide needed in the experiment?


  It is necessary for photosynthesis
• What should be done after placing the pond weed in the boiling tube?


  Leave it for five minutes to acclimatize
• What gas is produced by the pond weed during photosynthesis?

  Oxygen
• How do you measure the rate of photosynthesis in this experiment?


  Count the number of bubbles produced in one minute
• How many times should the counting of bubbles be repeated?


  Two more times
• What is the next step after calculating the mean number of bubbles produced?


  Repeat the experiment at different distances
• What distances should the experiment be repeated at?

  20 centimeters, 30 centimeters, and 40 centimeters
• What are the two main problems with counting bubbles in this practical?


  • Bubbles can be too fast to count accurately
  • Bubbles are not always the same size
• How can the problems with counting bubbles be solved?

  Measure the volume of oxygen produced instead of counting bubbles
• What equipment is used to measure the volume of oxygen produced?


  A measuring cylinder filled with water