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AQA BIOL5 Biology Unit 5 Exam - 22nd June 2011 watch

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  • View Poll Results: Are you resitting this unit?
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    ok, Here's an essay question from an old Human bio 08 paper.

    discuss 'The biological importance of plants to humans.'

    I'm gonna put my essay plan up, can ppl add topics/points to it that I haven't thought of? Breadth is a bit of a problem for me, I can't really 'think outside the box' very well!

    Plan:

    -plants used in photosynthesis which gives humans glucose (and then a brief description of the stages of photosynthesis)
    -so we can respire (brief respiration description)
    -needed for ATP. uses of ATP: metabolism, reactions, active transport, e.g. in muscle contractions (brief description of its role in moving calcium ions)

    I'm not sure whether these points are relevant for 'biological importance'. What does that even mean???!!!
    -Plants, when prevented for decay, gives fossil fuels
    -the nitrogen cycle (the leguminous plants) which give us ammonium ions


    I'm a bit stuck now. plus it says 'biological' -so can we even talk about fossil fuels?
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    (Original post by Jasmine_009)
    June 2010 paper question 6 (c) (ii)
    how might the insertion of the DNA might have caused cancer??
    in this question.....why cant we talk about mutation of proto-oncogenes?? the mark scheme only accepts comments on tummor suppressor gene
    I think it's because the tumor-suppressor gene it related to the "two hit hypothesis" and requires two mutations for it to be activated. With the proto-onco gene only one mutation is required to deactivate it. Had this problem in class a while back and i'm sure that was the reason
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    (Original post by angel1992)
    in my book nt it says, in vivo is advantageous as it cuts out specific genes not just replicating whole dna samples, but pcr cant replicate whole dna samples, it can only replicate small fragments of dna???
    PCR will replicate as much DNA as is required. There is no limit to the size of the molecule to be replicated providing excess free nucleotides are present
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    (Original post by ZacVR)
    I think it's because the proto-onco gene is the "two hit hypothesis" and requires two mutations for it to be activated. With the tumor-suppressor gene only one mutation is required to deactivate it. Had this problem in class a while back and i'm sure that was the reason
    in my nt book it says it says tumour supressor genes require two mutations to inactivate it, and proto oncogenes one
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    (Original post by angel1992)
    in my book nt it says, in vivo is advantageous as it cuts out specific genes not just replicating whole dna samples, but pcr cant replicate whole dna samples, it can only replicate small fragments of dna???
    Perhaps it is refering to the specificty of vivo gene cloning-specific enzymes- pcr replicates any DNA samples when they are small fragments
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    Guys, please tell me the specimen paper for this unit was a fail for everyone??? I just completely flopped, and its thrown me right off course
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    (Original post by angel1992)
    in my nt book it says it says tumour supressor genes require two mutations to inactivate it, and proto oncogenes one
    just edited post, wrote the genes the wrong way around
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    it also says in the book, a benefit of recombinant gene technology is genetic fingerprinting, but this doesnt involve recombinant dna?
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    (Original post by Count Stefular)
    Guys, please tell me the specimen paper for this unit was a fail for everyone??? I just completely flopped, and its thrown me right off course
    It had alot of errors in the mark scheme.But most questions were straightforward right?
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    (Original post by flf)
    ok, Here's an essay question from an old Human bio 08 paper.

    discuss 'The biological importance of plants to humans.'

    I'm gonna put my essay plan up, can ppl add topics/points to it that I haven't thought of? Breadth is a bit of a problem for me, I can't really 'think outside the box' very well!

    Plan:

    -plants used in photosynthesis which gives humans glucose (and then a brief description of the stages of photosynthesis)
    -so we can respire (brief respiration description)
    -needed for ATP. uses of ATP: metabolism, reactions, active transport, e.g. in muscle contractions (brief description of its role in moving calcium ions)

    I'm not sure whether these points are relevant for 'biological importance'. What does that even mean???!!!
    -Plants, when prevented for decay, gives fossil fuels
    -the nitrogen cycle (the leguminous plants) which give us ammonium ions


    I'm a bit stuck now. plus it says 'biological' -so can we even talk about fossil fuels?

    talk about how plants affect CO2 concentration- and link that to the effect on heart rate, haemoglobin activity etc etc
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    (Original post by angel1992)
    it also says in the book, a benefit of recombinant gene technology is genetic fingerprinting, but this doesnt involve recombinant dna?
    It can! If you have want to check a specific region. You can use the recombinant DNA of a particular mRNA right?
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    (Original post by Count Stefular)
    Guys, please tell me the specimen paper for this unit was a fail for everyone??? I just completely flopped, and its thrown me right off course
    I found it pretty horrible, and now I've been thrown back in the 'can't revise' rut.
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    (Original post by ZacVR)
    PCR will replicate as much DNA as is required. There is no limit to the size of the molecule to be replicated providing excess free nucleotides are present
    However if the DNA strand is too long the chance of error can get so high the it renders the copied DNA invalid?
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    I don't get any of that recombinant DNA stuff ! Please help
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    (Original post by Destroyviruses)
    It can! If you have want to check a specific region. You can use the recombinant DNA of a particular mRNA right?
    im confused, how is that recombinant dna? and how is that used ? ohhhh are you saying that dna is isolated by reverse transcriptase and so dna using this is recombiant which is then used in pcr and genetic fingerprinting?
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    (Original post by mbr)
    I don't get any of that recombinant DNA stuff ! Please help
    Which part? Like, in vivo cloning, or genetic modification?
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    What is a vector and how do they work? cuz i still dont really get that
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    woahhh everyone on here is in proper panic mode!
    although saying that i am too hahaha
    im not even going to attmept to try and understand positive and negative feedback properly lol
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    (Original post by cheekymon999)
    What is a vector and how do they work? cuz i still dont really get that
    a vector is something you can insert a new gene to. in the revision guide the main vector they use is bacterial plasmids. they are useful as vectors because they can be taken up by bacterial cells and can hence divide and reproduce to create multiple amounts of a gene. it is important that when inserting the wanted Gene in to a plasmid the same restriction endonuclease(enzyme used to cut DNA at specific points) on both the human DNA and plasmid is used. Therefore they can be complimentary and stick together using the enzyme ligase.
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    (Original post by appleschnapps)
    Which part? Like, in vivo cloning, or genetic modification?
    me too i'm really confused about probes and restriction mapping :-) please can anyone help with the ATP in muscle contraction as we have learned APT fixed to the myosin head removes the head from the binding site and the energy released from the hydrolysis moves the myosin head back to its original place. in other books it says various things from 2 lots of APT being used at various points, to one to only remove the head. i've contacted AQA and sent 5 different quotes from books and they have said they cant help and I must go back to my tutor. my tutor is going to say she is right but what do you do when 5 different books say different things? please help xxx
 
 
 
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