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AS Biology Investigations

Discussion in 'Science' started by BelleDuJour, Nov 25, 2011.

  1. BelleDuJour

    BelleDuJour Star commenter

    Go onto AQA website and look under A level biology. TBH as a physics graduate I cannot understand for the life of me why you are being given A level biology to teach.
    Anyway, go onto AQA and you'll find these experiments under ISAs. The spinach one I've done and it's pretty straighforward. It's the decolourising DCPIP if I remember correctly. AQA gives you lots of info.
     
  2. Dear BellDuJour
    Thank you for your quick reply.
    I went to the AQA Biology A level site (http://www.aqa.org.uk/qualifications/a-level/science/biology.php) and on the Key Materials tab under Teacher Resource Bank I found Investigative Skills Assessment (ISA) but there were just two pdf's:
    Guidance for teachers marking ISAs
    Instructions for the administration of the ISA
    Is this the correct link?
    Regards
    Len



     
  3. BelleDuJour

    BelleDuJour Star commenter

    You need to go onto e-AQA which is the secure part of AQA so you need to register and get al og on (do this through the school's exam officer). It's a relatively quick process. Failing that your exams officer can print it out for you or your HoD (or another Biology teacher) should be able to help.
    The chlorplast/DCPIP is the Sep 2009 - May 2010 Unit 6T ISA P. This can be found under 'past papers'.
    Any problems PM your email to me and I'll dowmload and forward to you.
    I've not located the pH/milk one but if I come across it I'll let you know.
    Hope that helps [​IMG]
     
  4. housesparrow

    housesparrow New commenter

    A very good book on practicals I used a lot was Advanced Biology Principles and Applications by C J Clegg, D G MacKean et al. There might be something newer - I suggest you join the Biotutor Discussion Forum - lots of Biology teachers there who will be able to recommend a decent up-to-date practical book http://www.biology4all.com/biotutor.asp
     
  5. Goat2

    Goat2 New commenter

    For chloroplasts
    http://www.practicalbiology.org/areas/advanced/energy/photosynthesis/investigating-the-light-dependent-reaction-in-photosynthesis,60,EXP.html
    and milk hydrolysis
    http://www.practicalbiology.org/areas/advanced/bio-molecules/quantitative-food-tests/a-quantitative-food-test-protein-content-of-powdered-milk,111,EXP.html
    The site has a vast range of biology which could help.
    Also try http://www.ncbe.reading.ac.uk/NCBE/PROTOCOLS/menu.html though none appeared to have chloroplast extraction
    Finally
    http://www.saps.org.uk/

    As a biologist I use the three NCBE, SAPS and Pract Bio regularly hence I know them but to be honest the answers came up too on a Google search!
    The below has a method for chloroplasts but it isn't half complicated!
    http://www.ableweb.org/volumes/vol-2/3-giebel.pdf

     
  6. BelleDuJour

    BelleDuJour Star commenter

    Hmmmm..............we've not managed to get any decolourisation of DCPIP. We've followed instructions perfectly and made up fresh solutions according to technician's notes on ISA. As we're using this as a practice ISA does anyone have a set of results I can have so the students can use them for the written task?
     
  7. Dear All
    Thank you for taking the time to reply to my enquiry - much appreciated.
    I think I will just extract the chloroplasts and not perform the decolourisation of DCPIP part.
    Cheers
    Len

     
  8. BelleDuJour

    BelleDuJour Star commenter

    In which case you'll just be liquidising spinach and filtering it! You won't be able to see the chloroplasts as they are only visible under an electron microscope. Not a lot of point to that..........the whole point is to decolourise with DCPIP, however tricky it might be.
     
  9. Hmm, I think you are right. The AQA specification does cover the extraction of cytoplasmic organells. I thought I would give my learners experience of using a centrifuge but just ending up with a green layer does sound pretty lame.
    Len
     
  10. BelleDuJour

    BelleDuJour Star commenter

    The students only need to understand how a centrifuge works, they do not have to use one.
    As regards this practical it is worth getting them to do the ISA as a practice exercise. Even though results are not good, there's a lot of practical techniques to use and the following written test is excellent for them.
     

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