core practicals p2

• effect of light intensity,photosynthesis:method


  1.place light at a set distance from the pond weed

  2.the oxygen produced in photosynthesis collects in the gas syringe

  3.the volume of oxygen produced in a set time is measured.

  4.the whole experiment is measured again with the light at seperate distances from the pondweed
• investigate effect of light intensity,photosynthesis: results 


  the further the light the lower the intensity of light reaching the pondweed
• rate of respiration: method


  1.set up respirometer

  2.use syringe to set the coloured liquid to a known level

  3.set a water bath to 15 degrees

  4.the wood lice will use up oxygen during respiration, the carbon dioxide that is released will be absorbed by the soda lime granuals

  5.there’ll be a decrease in the volume of the air in the tube containing the woodlice. this will cause the coloured liquid in the manometer to move towards the test tube containing the woodlice

  6. repeat steps with water bath at different temps to show how temperature affects the rate of respiration