Testing for starch

Discussion in 'Top Tips' started by Dr.Roo, Sep 27, 2016.

  1. Dr.Roo

    Dr.Roo Enjoying Science, Dresses, Shoes and Rugby.

    In other schools geraniums are kept when testing for starch.
    As we didn't have any geraniums, today we did a straight test using bind weed leaves and results were as expected when iodine was added. Leaves break down easily.

    But if you want to do a comparison between a plant that's been left in the dark for a couple of days then the geranium is the way to go. Bind weed (convovulous) is easier to water during the holidays though.
  2. We find the geraniums pretty hardy. They prefer to be dry, we given them a good water before the holidays and they are fine when we come back, even after the 7 weeks of summer this year!
  3. 007


    We have plenty of privet bush around the school site which also provides good results :)
  4. that is so cool.
  5. I had some success with buddleia last year (my old school was rife with it and had enough pupils to use up a whole geranium forest, so it was the most economical option). For the plant in the dark I covered one with a big opaque groundsheet.

    Another very good one in a pinch was basil (the plants you get from the supermarket in pots).Worked perfectly, very deep black, very easy to remove the chlorophyll and made the room smell lovely to boot! :D

    Of course, my favourite option in the grimmest winter weather (the kind when no sane human being should be doing practical biology) is to dust the geraniums with some starch powder before giving them out and tell the kids it's pesticide if they notice ;) (I also knew a teacher who would wander round stirring pupils' beakers with a starchy stirring rod).
    Claire, clairelucas and Jade like this.

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