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    How Wavelength of Light Affects Photosynthesis.: Control Group

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    suru suru
    The document discusses how the wavelength of light affects photosynthesis in Elodea plants. It states the null hypothesis that green light decreases photosynthesis, while the alternative hypothesis is that red and violet wavelengths increase photosynthesis by allowing more steps in the light-dependent and light-independent reactions. The experiment varies the light wavelength and measures the rate of oxygen bubble production from sodium hydrogen carbonate surrounding an Elodea plant. Control variables like light intensity, temperature, and sodium hydrogen carbonate concentration are kept constant to isolate the independent variable of light wavelength.

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    How Wavelength of Light Affects Photosynthesis.: Control Group

    Uploaded by

    suru suru
    29 views2 pages
    The document discusses how the wavelength of light affects photosynthesis in Elodea plants. It states the null hypothesis that green light decreases photosynthesis, while the alternative hypothesis is that red and violet wavelengths increase photosynthesis by allowing more steps in the light-dependent and light-independent reactions. The experiment varies the light wavelength and measures the rate of oxygen bubble production from sodium hydrogen carbonate surrounding an Elodea plant. Control variables like light intensity, temperature, and sodium hydrogen carbonate concentration are kept constant to isolate the independent variable of light wavelength.

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    The document discusses how the wavelength of light affects photosynthesis in Elodea plants. It states the null hypothesis that green light decreases photosynthesis, while the alternative hypothesis is that red and violet wavelengths increase photosynthesis by allowing more steps in the light-dependent and light-independent reactions. The experiment varies the light wavelength and measures the rate of oxygen bubble production from sodium hydrogen carbonate surrounding an Elodea plant. Control variables like light intensity, temperature, and sodium hydrogen carbonate concentration are kept constant to isolate the independent variable of light wavelength.

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    29 views2 pages

    How Wavelength of Light Affects Photosynthesis.: Control Group

    Uploaded by

    suru suru
    The document discusses how the wavelength of light affects photosynthesis in Elodea plants. It states the null hypothesis that green light decreases photosynthesis, while the alternative hypothesis is that red and violet wavelengths increase photosynthesis by allowing more steps in the light-dependent and light-independent reactions. The experiment varies the light wavelength and measures the rate of oxygen bubble production from sodium hydrogen carbonate surrounding an Elodea plant. Control variables like light intensity, temperature, and sodium hydrogen carbonate concentration are kept constant to isolate the independent variable of light wavelength.

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    of 2

    How wavelength of Light affects photosynthesis.

    The null hypothesis is that Wavelength of light that is green light decrease photosynthesis.

    The alternates hypothesis states increasing wavelength of light such as red or violet will have a
    significant positive impact on the potential growth of the plants as they are green they are
    absorbing the other wavelengths of light but reflecting back the green. This would allow them to
    go through many steps of Light dependent and light Independent reaction, producing greater
    amount of oxygen and glucose.

    The Independent variable


    The wavelength of the light is being varied by altering the light color ( 5 different colors)
    including white color.

    Dependent variable
    The rate at which the plant Elodea synthesises

    Control variable
    Light intensity: the ​lamp will be kept 10cm away from the Elodea plant at all times hence no
    additional effect on the rate of photosynthesis.

    Room temperature in degrees Celsius: the temperature of the room will be kept 25 degrees celsius
    at all times as well as no air conditioning or open windows will be present to prevent any additional
    affect on the rate of photosynthesis.

    Concentration of Sodium hydrogen Carbonate: the concentration will be 5 mol/dm3 at all times to
    prevent any additional affect on the rate of photosynthesis.

    Time provided for measuring the rate of photosynthesis: the bubbles produced will be measured
    every 40 seconds.

    Control group: ​Another Elodea plant is given normal conditions and they are not provided with
    additional features that could increase or decrease their rate of photosynthesis. Their wavelength of
    light should be red at all times. This allows us to compare the rate at how both the Elodea plants
    differ in terms of photosynthesis.

    Apparatus:
    -Light bulb
    -Elodea plant
    - 1% of 200cm3 of Sodium hydrogen carbonate
    -200 cm3 beaker
    -thermometers
    -safety goggles
    -5 colour filters
    -boiling tube
    -stop watch
    -ruler

    Method
    1- set up the apparatus
    2- add your sample of elodea plant into the boiling tube
    3-Fill boiling tube containing the elodea plant with 1% Sodium Hydrogen Carbonate. Fill it till it
    covers the plant.
    4-record the temperature (make sure it is at 25 degrees celsius)
    5-Plug in the 100W light bulb in and turn it on to its side so that it is facing the beaker. Place it 10cm
    away from the beaker.
    6-Allow the beaker to adapt for 2 minutes and return to starting temperature before beginning net
    experiment
    7-After 2 minutes count the number of bubbles that appeared with 40 second increments in 2 ½
    minutes.
    8-Record the number of bubbles given off
    9-Change the colour of the filter and allow the plant to acclimatise for 2 minutes again before
    repeating the experiment.
    10-Repeat the experiment again with a different wavelength of light
    11- put your results in a table and draw the graph: showing how rate alters with wavelength of
    light.

    Risk assessment

    Risk Why it is harmful Solution

    Bright Light It could cause damage to the The student is not facing the
    retina of the eye light directly

    Sodium hydrogen carbonate Could cause damage to the Wear safety goggles
    eyes if comes in contact with
    it

    Beaker Made of glass and can break It is kept away from the edge
    of the floor

    By: Suraksha Mukesh

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