Varying The Distance Of Elodea
Conclusion
The aim of this experiment was to investigate the effect of varying the distance (cm) of the Elodea plant from the light source at (5, 15, 25, 35 and 45 (cm)) (±0.05) on the photosynthetic rate by counting the number of oxygen bubbles rising up the test tube per minute (bubbles min^(-1)).
The hypothesis was supported because as the light intensity increased, the rate at which oxygen bubbles rising to the top of the test tube also increased – for example, at the closest distance of 5 cm, the rate of photosynthesis was at its highest, with the optimum amount of oxygen bubbles being produced. At a distance of 5cm, the average number of bubbles counted for one minute was 175. At 15cm, a slight decrease in the number of bubbles was calculated (111 bubbles). At 25cm however, a significant decrease was calculated, with only 63 bubbles. At 35cm and 45cm, the number of bubbles counted for one minute was 46 and 25 respectively. Graph 1.1 precisely depicts the decrease in the total number of …show more content…
Due to capillary action, an incorrect reading may have taken place. An incorrect reading of sodium bicarbonate has the potential to influence the results as it is a limiting factor of photosynthesis. An improvement to this limitation would be to use a calibrated pipette to ensure only the required amount of sodium carbonate is used.
Also, the way the bubbles were counted was subjective to the human eye, and this could have led to inaccuracies in the number of bubbles being generated. It is possible that bubbles were counted twice or possibly missed completely. Also, it is possible that some bubbles stayed under the (Elodea) plant leaves and were therefore missed in the counting of bubbles. An improvement to this limitation would be to use a photosynthometer – a highly calibrated device that can be used to measure the photosynthetic rate of the Elodea
The aim of this experiment was to investigate the effect of varying the distance (cm) of the Elodea plant from the light source at (5, 15, 25, 35 and 45 (cm)) (±0.05) on the photosynthetic rate by counting the number of oxygen bubbles rising up the test tube per minute (bubbles min^(-1)).
The hypothesis was supported because as the light intensity increased, the rate at which oxygen bubbles rising to the top of the test tube also increased – for example, at the closest distance of 5 cm, the rate of photosynthesis was at its highest, with the optimum amount of oxygen bubbles being produced. At a distance of 5cm, the average number of bubbles counted for one minute was 175. At 15cm, a slight decrease in the number of bubbles was calculated (111 bubbles). At 25cm however, a significant decrease was calculated, with only 63 bubbles. At 35cm and 45cm, the number of bubbles counted for one minute was 46 and 25 respectively. Graph 1.1 precisely depicts the decrease in the total number of …show more content…
Due to capillary action, an incorrect reading may have taken place. An incorrect reading of sodium bicarbonate has the potential to influence the results as it is a limiting factor of photosynthesis. An improvement to this limitation would be to use a calibrated pipette to ensure only the required amount of sodium carbonate is used.
Also, the way the bubbles were counted was subjective to the human eye, and this could have led to inaccuracies in the number of bubbles being generated. It is possible that bubbles were counted twice or possibly missed completely. Also, it is possible that some bubbles stayed under the (Elodea) plant leaves and were therefore missed in the counting of bubbles. An improvement to this limitation would be to use a photosynthometer – a highly calibrated device that can be used to measure the photosynthetic rate of the Elodea