• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

The effect of varying light intensity on the rate of Photosynthesis of the aquatic plant Elodea.

Extracts from this document...

Introduction

The effect of varying light intensity on the rate of Photosynthesis of the aquatic plant Elodea Mubasher 10B Data Analysis Distance of lamp Length of bubble after 5 minutes (mm) Average length Light Intensity from plant (cm) of bubble (Lux) 5 29 49 52 56 56 59 50.17 4000 10 12 21 22 27 26 30 23 1000 15 9 9 10 12 14 13 11.17 444.4 30 2 3 3 2 5 4 3.17 111.1 50 1 2 2 1 1 2 1.50 40 Light intensity workings: 1/distance2 * 100,000 = 1/52 * 100,000 = 1/25 * 100,000 = 4000 For all the rest, workings are the same. Graph See other sheet Conclusion The pattern shown on the above graph shows that as you increase the light intensity the rate of photosynthesis increases at a decreasing rate. Sunlight + Chlorophyll Carbon dioxide + Water Oxygen + Glucose + Energy These results tell me that an increase in light intensity does increase the rate of photosynthesis. The gradual decrease in the rate of photosynthesis (the straightening of the curve) can be linked to the other factors limiting the rate of photosynthesis. ...read more.

Middle

This is because the light is increasing constantly. However the rate of photosynthesis decreases at the end because the chlorophyll has got enough energy but needs more carbon dioxide to combine with water to increase the rate. This part of the graph shows me that the increase in rate is proportional to the increase in light intensity (i.e. a straight line) and I can show this by taking some readings from the graph (See other Sheet) Evaluation I have identified two anomalous results which are highlighted on the table in red. There were errors in the experiment which could have caused this. Some human errors and some errors we can't help. Measuring the distance from the filament to the plant each time, measuring the length of the bubble and timing are human errors Also when the lamp is close to the plant it gives it heat energy as well. This will increase the rate of photosynthesis so our bubble will become bigger. This only really affects the plant when is close to it. ...read more.

Conclusion

Give it two minutes to settle and adjust to the new light intensity. 5) Start the stopwatch and count the number of bubbles produced in one minute. 6) Repeat 5 times 7) Repeat steps 4, 5 and 6 with distances 30cm, 15cm, 10cm and 5cm. Distance of lamp Amount of bubbles after 1 minute Average amount Light Intensity from plant (cm) of bubbles (Lux) 5 10 15 30 50 A glass wall is kept in front of the beaker so no heat from the lamp can affect the rate of Photosynthesis. After getting all the data I would plot some of the data on a graph. I would plot the amount of bubbles with the light intensity. Then I could find out how light intensity affects Elodea with greater accuracy. To get extra information about the rate of photosynthesis, I could try to relate some of the other limiting factors to the same experiment, as well as investigating them on their own. It could also be worthwhile to explore the effects of coloured lights on the rate of photosynthesis, which could lead to other experiments such as whether or not other types of light, such as fluorescent lights or halogen lights, would have a different effect on the rate of photosynthesis. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Green Plants as Organisms section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related GCSE Green Plants as Organisms essays

  1. Marked by a teacher

    An investigation into the effect of light intensity on the rate of photosynthesis of ...

    5 star(s)

    They are just about within 10% of their mean value. It is impossible to say how much error there is in my reading. Firstly, the distance between the light sources and the Canadian Pondweed were not measured to a very high degree of accuracy, especially when you note the fact

  2. Marked by a teacher

    Investigation to find out how light intensity effects the rate of photosynthesis

    4 star(s)

    Microorganisms living on the pondweed may have even used some oxygen. The amount of oxygen dissolved or used by microbes is probably insignificant to my results since the degree of accuracy at which I measured was not high enough. Some oxygen is also used during the respiration of the plant.

  1. Investigating the effect of Light Intensity on Elodea.

    Fill a beaker with water (500cm3) of water and add a spatula of sodium hydrogen carbonate. Place a funnel and an upturned test tube full of water over the Elodea (as shown below): Measure a distance with a 1m rule e.g. 50cm from the plant and place the lamp there.

  2. What affects the rate of photosynthesis in Elodea?

    I think that repeating the experiment a fourth time is not necessary because the results that we have already are similar enough to each other that I can happily say that all 3 experiments were a success. Analysis The most obvious observation from my investigation out that the elodea releases oxygen bubbles i.e.

  1. This experiment involves using a photosynthometer to investigate how temperature affects the rate of ...

    Acknowledgements: 12- Diagram modified from A-Level biology Revised Edition by W D Phillips and T J Chilton, page 69. Analysis of Variables: Independent variable: The independent variable is the variable, which has to be manipulated in order to get the desired results.

  2. How temperature affects the rate of photosynthesis.

    Therefore the overall rate of photosynthesis is low. Although the reactions are being catalysed, but these reactions are occurring at a very low rate. The activation energy required for the reaction is decreased, but is not decreased by a great amount and still a high amount of energy is required to reach the transition stage and to from the enzyme substrate complex.

  1. Investigating the effect of temperature on the rate of photosynthesis

    Number of bubbles released 10 18 30 240 50 12 70 7 Evaluation During our preliminary experiment, many errors occurred which would affect the accuracy and results of the experiment. Changing the following will do this: The room the experiment was carried out in was not dark enough, therefore light intensity is affected and cannot be controlled.

  2. Investigate the effect of light intensity and the colour of light on the rate ...

    Find the length of the bubble collected. Repeat for all other readings, Sciencetific knowledge: Only green plants can make their own food by the process called photosynthesis. Hence, green plants are known as food producers. All other organisms are called food consumers as they depend directly or indirectly on green plants for food.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work