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

In this experiment we are going to investigate if increased light intensity will increase the rate of photosynthesis in the water plant Elodea. We will monitor the rate by counting the number of bubbles of oxygen formed

Extracts from this document...

Introduction

Name: Laura Akinyi Class: IB1 Subject: Biology Collaborator: Intisar Ahmed and Timmoi Lawoko Date of performance: 2 December 08 The Effect of light intensity on the rate of photosynthesis Introduction Light intensity is one of the three factors that can determine the rate of photosynthesis. Changing the level of this changes the rate of photosynthesis. In this experiment we are going to investigate if increased light intensity will increase the rate of photosynthesis in the water plant Elodea. We will monitor the rate by counting the number of bubbles of oxygen formed or by measuring the volume of oxygen gas formed. We hypothesized that the shorter the distance (independent variable) is between the light source and the plant the more the bubbles (dependent variable) will be formed. Material See instruction sheet. Method 1. Add a spoon of sodium hydrogen carbonate to water in a container and mix. ...read more.

Middle

Place the lamp closer to the plant and measure the distance. Results The number and volume of bubbles formed at different distances from the light source Distance the light source (cm) Temperature before the test Temperature during the test Number of bubbles produced during ten minutes� 1 The volume of the gas formed during ten minutes in cm 1. 47cm 22�C 23�C 148 � 1 0.125 cm 2. 40cm 22�C 21�C 153 � 1 0.125 cm 3. 33cm 20�C 22�C 262 � 1 0.25 cm 4. 24cm 21�C 21�C 266 � 1 0.25 cm 5. 8cm 20�C 20�C 262 � 1 0.25 cm We found that the closer the elodea plant got closer to the light source the more bubbles were formed. However the nearest distance (8 cm) from the elodea plant to the source of light produced less bubbles than the second distance (24cm) thus our experiment supported the prediction to a certain extent. ...read more.

Conclusion

All the carbon dioxide was used up. The temperature was not kept constant. The different trials had different temperatures this was a systematic error since temperature also affects the rate of photosynthesis. Random errors like counting the bubbles inaccurately might have also led to the imprecision. Evaluation The design and method of this investigation was not accurate since some variable such as carbon dioxide and temperature were not kept constant. The weaknesses such as measuring the light intensity by calibrating the distance was not reliable, we should have used a better equipment or method to measure light intensity like using a reliable equipment e.g. a lux meter. We should also wait for a while in each experiment before staring to count the bubbles so that the plant may adjust to the new conditions. To reduce systematic errors we should keep the other variables that affect the experiment like carbon dioxide and temperature constant. We could do this ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our International Baccalaureate Biology 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 International Baccalaureate Biology essays

  1. Marked by a teacher

    Neurology and Behaviour. Focus question: Is there an increase in the perception and ...

    5 star(s)

    of several other studies in suggesting that females have stronger feelings of disgust than their male counterparts. This difference in the disgust response may not simply be due to the genetic composure of men and women but rather their trained responses or environmental factors which influence their behaviour and emotions.

  2. affect of light intensity on rate of photosynthesis

    Controlled variables: * Equal (75 ml) amount of water to be put in each beaker was ensure by the measuring marks on the beaker itself. This helps to have the same ratio between NaCOH3 and water in all 5 beakers * Exactly 1g of NaHCO3 was weighted using balance then put into each beaker.

  1. In this extended essay I am looking at the effect of different kind of ...

    Observations (after several hours): All the seeds have swollen up and have changed their colours from dark brown to light brown. Day 2: Observations: All the seeds are swollen and the radicle is visible. The pictures are shown of seeds on day 2 is shown below: Day 3: => Take the seeds and bury them in cup filled with cups.

  2. Extended Essay- How is production of carbon dioxide (CO2) during digestion affected by the ...

    2008. Flatulence Odor Solution, Web. 28 Oct 2009. <http://www.flat-d.com/flatulence.html>. 30. "Reasons for farting and belching ." Embarrassing Problems. 04 April 2009. Health Press Ltd., Web. 28 Oct 2009. <http://www.embarrassingproblems.com/wind_reasons.htm >. 31. "Fart or Flatulence." Hemorrhoids in Plain English. 2009. Hemorrhoids in Plain English, Web. 28 Oct 2009. <http://www.hemorrhoidsinplainenglish.com/anorectal/flatulence.htm>. 32.

  1. The effect of light intensity on cyclosis on Elodea leaf cells

    In addition, the temperature at which the experiment took place was not controlled, water supply was not monitored and the CO2 concentration was not taken into account. Human errors: The 12th reading of 1 lamp may have human attention span/concentration error since the time measured was much shorter than the average time taken by chloroplast (i.e.)

  2. Environmental Factors affecting plant growth

    0 0 0 0.7 1.3 0 0 0 4 0 3 2 3 2 0 3.1 0 2.6 1.3 5 1 1 0 2 2 0.7 0 4.2 0.4 2.3 Day 9 1 0 0 2 2 2 0 1.2 0 2.6 3.3 Not applicable 2 2 1 0 2

  1. Testing the dissolved oxygen levels in water samples.

    The iodine is then titrated with thiosulfate to find this quantity. Hypothesis The temperature and amount of light an aquatic environment receives greatly affects the dissolved oxygen levels, along with the amount of primary aquatic productivity. Materials Measurement of Dissolved Oxygen This part of the lab required a sample bottle

  2. How does the salinity of water affect the germination of mung been seeds as ...

    gibberellic acid to be produced and as the seed absorbs water and swells the testa will begin to crack. Gibberellic acid in tern causes the synthesis of amylase, which breaks down the starch contained within the cotyledon into maltose. The maltose can then be hydrolysed to glucose for respiration of polymerised to form cellulose, necessary for plant walls.

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