Hi guys, could someone please provide me some feedback on this prac report i wrote 🙏
This was the prompt:
Scenario:
A student wanted to investigate how changing carbon dioxide (CO₂) concentration affects the rate of photosynthesis in pondweed. They placed a sprig of pondweed in water and added different amounts of sodium bicarbonate (which releases CO₂). They then counted the number of oxygen bubbles released per minute.
CO₂ Concentration (%) Bubbles per Minute
0.00 2
0.01 8
0.03 18
0.05 22
0.07 21
0.09 18
Observations:
Photosynthesis rate increases at first
Peaks around 0.05% CO₂
Then begins to decline — you’ll need to explain why
Posible issues:
Were all pondweed pieces the same size?
Was light kept constant?
Did water temperature affect the result?
My response:
Title: The Effect of Carbon Dioxide Levels on Photosynthesis Rates
Introduction:
Photosynthesis is the process through which plants convert sunlight and carbon dioxide into glucose for their everyday energy needs. This process produces oxygen which is then released back into the environment for other living organisms to breathe. The rate of carbon dioxide in an environment is vital to the amount of oxygen bubbles produced.
Aim:
To investigate the effect of carbon dioxide levels on the the rate of photosynthesis.
Hypothesis:
Because carbon dioxide is a raw material for photosynthesis, increased amounts will lead to increased levels of oxygen produced.
Method/Apparatus:
- Fill 6 of the same type of beakers with equal amounts of water.
- Place a sprig of pondweed in each of the beakers.
- Add amounts of sodium bicarbonate with different concentrations of carbon dioxide, 0.00%, 0.01%, 0.03%, 0.05%, 0.07%, and 0.09%.
- Observe and note down the number of bubbles produced per minute in each of the beakers.
Results:
Carbon Dioxide Concentration (%): Bubbles Per Minute:
0.00 2
0.01 8
0.03 18
0.05 22
0.07 21
0.09 18
Analysis:
These results show a mostly clear correlation between the amount of bubbles produced and the concentration of carbon dioxide. The amount of bubbles produced peaks at 0.05% carbon dioxide concentration and steadily decreases from there, with the number starting from 2, then peaking at 22, and gradually decreasing to 18.
Discussion:
These results mostly support the hypothesis, however, the latter part of the results do not support it. There is a sharp uptick in the amount of bubbles produced from 0.01% carbon dioxide concentration to 0.03%. After peaking at 0.05% the amount of bubbles steadily decreases, illustrating the fact that there are other factors at play.
There were numerous flaws presented in this experiment as it has not been mentioned whether the pondweed samples were of the same size, whether the amount of UV exposure was the same for each of the beakers, and whether there was a difference in temperature that affected the pondweed samples.
Conclusion:
To conclude, the results from this experiment mostly supported the hypothesis, however, the abnormal decrease in the number of bubbles produced from 0.05% to 0.07% and 0.09% suggested that there were some unaccounted factors in the experiment which were not controlled.
tysm!
