What is the best conditions for photosynthesis in the science lab?[Part 2]

All of the following are based on the experiment we conducted in 13 August 2010 and there were some problems encountered:

Methods:

1)Fill 3 transparent beakers with water and add sodium hydrogen carbonate

2)Place a hydrilla in each of the beakers

3)Label them Small , Large and Medium accordingly

4)Place a funnel inverted over the hydrilla such that the small opening is facing upwards

5)Place a test tube filled with water over the small opening of the funnel

6)Place lamps over the beakers and turn on

7)Observe for 10 minutes

8)Record results with data logger by placing oxygen sensor in the test tube

Results :

Surface area of leaves	Oxygen Level(mg/L)
Large	12.74
Medium	12.74
Small	12.73

Note:Normal oxygen level in water is 8.28 mg/L

Observations: After 10 Minutes , with the three hydrilla samples(Large,Medium and Small) submerged in the water.We observed that the hydrilla labeled Large and the one labeled Medium had 1 air bubble entering the test tube and the hydrilla labeled Small did not have any air bubble entering the test tube at all.

Report: Problems encounter in the experiment was that we were unable to get a lamp for each beaker or an accurate device to measure the amount of sodium hydrogen carbonate hence they were inconstant. Also , the difference in the surface area of the leaves were minute and hence , we have leaves with almost similar sizes.

Conclusion:The surface area of the leaves hardly affect the rate of photosynthesis.

Other than all the recorded things , these are our opinions on the experiment.

Karthik:It could be due to colour of the light.We just used white light.We could have used the blue,green and red filter papers provided.Doing such could change the results.

Kok Xuan:Maybe something went wrong , causing there to be only 1 bubble , or none at all.

Robina:The experiment failed due to the wrong way of doing it and there should have been more light so that the plants could photosynthesize. Since little light was used, we got the same results for two experiments.

Derrick:

HanXue:The timing is too short for plants to carry out photosynthesis,and the amount of light gave to each plant is not the same.So there is experiment errors.