Photosynthesis

• Pondweed used to measure the effect of light intensity on the rate of photosynthesis
• Method:

  • A lamp is placed at a specific distance from the pondweed, e.g. 10 cm
  • The pondweed is left to photosynthesise, oxygen will be released as bubbles which you should count
  • After a set ammount of time, move the lamp further away from the duckweed, leave to photosynthesise and count the O2 bubbles
  • Repeat for each distance
• As distance increases, the light intesity decreases. This is because light intensity is inversely proportional to distance.
• Light intensity can be calculated using the equation 1/d^2 (distance squared)