Woodlice: Choice Chamber

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  • Topic: Choice, Chi-square distribution, Light
  • Pages : 2 (443 words )
  • Download(s) : 483
  • Published : April 8, 2013
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To investigate the habitats woodlice prefer is dark condition or wet condition 1. Use a shoebox and place some soil and dry leaves in it. Start looking under rocks or bricks for some woodlice and place them in the shoebox. Make sure the soil is placed enough and evenly to keep the woodlice happy when not under investigation. * 25 woodlice were used for the experiment because the more woodlice used increases the statistics of which condition the woodlice prefer and give a more accurate data.

2. Set up a choice chamber with wet cotton wool on the base. Light source is placed at a constant distance from the choice chamber. A silver foil is then used to wrap up one side of the choice chamber. Netting will be placed over the top so the woodlice can walk over it.  * A choice chamber was chosen to use in the experiment because it gives choices of two different conditions such as differences in light intensity or dampness. * A lamp, acting as the light source was placed 20cm from the choice chamber and remained constant throughout the experiment. * Two petri dishes can be cut and glued together; another two petri dishes were placed upside down to cover the first two petri dishes, making a simple choice chamber. * There is a problem with the woodlice clumping up with each other (this is one of the things they naturally do when the get close to something or each other). It  may affect the distribution but unfortunately there isn’t a solution for this problem.

3. The 25 woodlice are then placed in the choice chamber for them to choose which condition they prefer. The results are taken down every minute for twenty minutes to put in a graph. * A digital stopwatch was started as soon as the woodlice have all been placed in  the choice chamber.

* The experiment was done for twenty minutes because it enables a chi- squared test to be done at the end of the experiment. The chi- squared test is a test that checks the reliability of the...
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