Laboratory Report on Oxygen Bubbling Experiment to Investigate of the Effect of Light Intensity on the Rate of Photosynthesis

Biology
Laboratory report on oxygen bubbling experiment to investigate of the effect of light intensity on the rate of photosynthesis

Objective
To investigate the effect of light intensity on the rate of photosynthesis.

Principle of design and Assumptions
It is known that light is required in the photochemical stage of photosynthesis. Nonetheless, it is uncertain that if rate of photosynthesis is related to light intensity.
Since oxygen is the produced from the photolysis of water in light dependent stage of photosynthesis, the amount of oxygen released per unit time reflects the rate of photosynthesis.
In the experiment, light intensity is varied by changing the distance of a bench lamp from the plant. It is assumed that light intensity varies inversely with the square of distance.

Hypothesis
It is predicted that the higher light intensity, the higher rate of photosynthesis, i.e. rate of photosynthesis is inversely proportional to the square of distance between light source and plant.

Apparatus and Materials
1 pipette                                                   1 pair of scissors
1 boiling tube                                           1 meter rule
1 beaker (500cm3)                                     rubber tubing
1 thermometer                                           0.25% sodium hydrogencarbonate solution
1 stand and clamp                                     Hydrilla plants
1 clip
1 bench lamp

Procedure
  1. Cut the stem of a Hydrilla plant to about 10 cm long under water
  2. Set up the apparatus as shown in Figure A.
  3. Adjust the distance of the bench lamp to 0.1m from the plant. Turn on the lamp and allow the plant to equilibrate for 5 minutes.
  4. Such up the solution from the boiling tube. Close the clip completely. Record the starting position of the meniscus in the pipette
  5. Record the initial reading of the water level in the pipette
  6. Wait for 5 minutes and record the final readings in pipette....