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

Experiment. The dependence of the rate of photosynthesis on light intensity

Extracts from this document...

Introduction

The dependence of photosynthetic rate on light intensity Introduction The existence of the animal kingdom, including humans, would be impossible without plants, which determines their specific role in the life of our planet. Of all the organisms only by plants and photosynthetic bacteria are able to accumulate the energy from the sun, creating it by means of organic matter from inorganic substances. By the plants' activity was created an atmosphere containing O2, and by their existence it's maintained in a condition suitable for breathing. Light plays an equally important role than soil moisture, air and heat in the normal course of vital activity of plants. Without any light higher plants cannot exist. The only light source that is able to completely support the vital activities of plants, is the sun. Light of the moon, planets and stars, although useful, but not satisfied in this regard to all the needs of plants. Thus, we have been interested in the question: "Does the light level is connected with the process of photosynthesis - one of the main functions of the plants?" ...read more.

Middle

Materials and Methods Materials: puncher, cups, medical syringes with 10 ml cylinder, the leaves of plants Method: We have made a few cuttings of the leaf by using the puncher and infiltrate them with water saturated with CO2. Infiltrated cuttings have been placed in the cups with water enriched CO2. One cup we have placed in the dark box (control group), second cup under the table where light level is low and third one on the windowsill where light level is high. Well, in the end of the experiment the cuttings have had to float but in different cups in different time. So, as a result of accumulation in the intercellular spaces of the oxygen formed during photosynthesis, all the cuttings placed in the third cup that have stayed on the windowsill have had to float but the cuttings placed in the cup that have stayed in the dark box have not had to float at all. Results Well, our results have justified the main theory. ...read more.

Conclusion

First, it's some weaknesses in internal validity that I describe before. The level of sunlight might change not once on this period of time, so it could make a strong influence on our experiment. Probably due this 6th cutting didn't float. Besides, the concentration of soda might be not 0.5% but more or less, so it could made strong influence on the results of the experiment too. Besides, it could change the results in all cups. So, these mistakes jeopardize all of the results of the experiment but anyway I suppose that our experiment have been successful because we have justified the theory. Suggestion for improving investigation As for me, the only things that we can really change is to be much careful with making a soda concentration and probably use the light bulb instead sunlight. First, the concentration of soda plays an important role in this experiment and thus we need to use a special equipment to make right concentration. Then the sunlight is not the best light source for this experiment, as I said before, because it's really fickle, so I would be better to use the light bulb in this experiment. Syromolotov Igor ?? ?? ?? ?? ...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. Experiment - Influencing the Rate of Photosynthesis with Light Intensity and Carbon Dioxide Concentration

    * Time used to count bubbles produce (5 minutes) * Height of lamp * Amount of Sodium bicarbonate (1 gram) * Heat intensity The distance of the lamp was changed, and the number of bubbles produced in the test tube was counted.

  2. affect of light intensity on rate of photosynthesis

    Beaker E is used as controlled, it is tested without the present of light from the lamp Independent variable: Distance from the lamp (light intensity) Dependent variable: pH of the solution (rate of photosynthesis) Controlled variables: * Equal (75 ml)

  1. Factors Affecting the Rate of Photosynthesis Lab

    Record the number of bubbles the elodea produces every 30 seconds for 1 minute and 30 seconds 10. Using a lux meter, locate the spot that the beaker needs to be placed so that it is shined on with 245 lux and let the beaker sit for 1 minute 11.

  2. Testing the effect of characteristics of leaves on the transpiration rate of * ...

    � water � a clamp stand � 2 x clamps � stopwatch � a 30cm ruler (� 0.1 cm) � sheets of squared paper (1cm grid) � a calculator Method 1. Cut four different kinds of branch of plants using secateurs *Make sure the thickness of the branches fits well to the rubbing tube of a potometer 2.

  1. Laboratory work on a theme The dependence of the rate of photosynthesis on ...

    have floated almost every. The circles which were on the distance of 25 cm have floated only 3. And the only one circle has floated in the farthest cup (50 cm). DISCUSSION Data Analysis and Conclusion Analyzing result of the experiment, I made a conclusion that O2 wouldn't produce without light energy.

  2. Plan for an experiment - How does temperature affect the rate of photosynthesis?

    I also need to make sure that light intensity is in excess for this experiment, so that it doesn?t become a limiting factor. Therefore, I will be using a bright light 20cm away from the photosynthometer for each condition. As the bulb produces heat energy as well as light energy, this could also alter the results of my investigation.

  1. Biology lab - testing the effects of light intensity on photosynthesis.

    Independent variables: intensity of light, baking soda Dependent variable: amount of elodea, temperature Controlled variable: amount of oxygen MATERIALS * 4 cut pieces of aquatic plant (Elodea) * 4 test tubes * distilled water (boiled and brought to room temperature)

  2. What is photosynthesis?

    Chlorophyll a and Chlorophyll b take place in photosynthetic process, whereas caretenoids function in protecting the chlorophyll from the excessive light energy that could harm the chlorophyll An overview of the photosynthetic process In the photosynthetic process, O2 produced comes from H2O and the sugar molecules come from CO2.

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