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    (Original post by ConnorB)
    a process of homoeostasis such as Vasolidation or Sweating which maintains constant internal temperature from small deviations in the external environment?
    well yeah you are correct but you gave me an EXAMPLE of negative feedback, i need its definition.....
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    (Original post by iesians)
    yup we do !
    someone on this page posted a 100% correct answer chk it out !
    Well it's not too much extra to learn :P

    Does anyone else think that Transcription factors will come up in the pre-release?
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    Has anyone got notes on GM's ? only topic I know **** about
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    (Original post by ConnorB)
    Well it's not too much extra to learn :P

    Does anyone else think that Transcription factors will come up in the pre-release?
    Outline role of transcription factors which lead to higher expression of PRDM16 in BAT than WAT, i'm sensing that...
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    (Original post by ConnorB)
    Well it's not too much extra to learn :P

    Does anyone else think that Transcription factors will come up in the pre-release?
    Yes yes yes. I think it will previously has in one of the old article questions.
    Care to explain what Transcription factors are etcc.
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    (Original post by iesians)
    well yeah you are correct but you gave me an EXAMPLE of negative feedback, i need its definition.....
    Negative feedback is the mechanism which restores the body temperature to normal when any change occurs - therefore, negative feedback means that the system only kicks into action when a change occurs.
    Homeostatic systems involve receptors, a communication system and effectors. The receptors detect the change in level and the effectors counteract the change. Negative feedback only works within limits i.e when the change is small ...

    hope this helps
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    (Original post by ZTSR)
    Yes yes yes. I think it will previously has in one of the old article questions.
    Care to explain what Transcription factors are etcc.
    Transcription factors are proteins that control the transcription of genes. Basically, they bind to DNA sites and increase or decrease the rate of transcription. They can be activators or repressors.
    An example given in the CGP guide is the thyroid hormone recpetor. Ideally, it slows down the transcription of a protein that controls metabolism. Howver, when thyroxine binds to it, it speeds up the rate, acting as an activator. More protein is produced and increase body temperatur

    EDIT: just saw you didnt actually want to know. Sorry, but its out there now
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    Hey guys!

    So I have been revising a lot, did lots of past papers, did go through all the spec. points but the one thing always holding me back in biology is the HSW.
    I just can't seem to know what the mark scheme wants, especially if you have to apply your knowledge to an unfamiliar scenario (which always comes up!)
    Can someone please give me advice on how to overcome this tomorrow? I will give rep points to those who give good advice, as I really need an A/A* in tomorrows paper.
    Good luck!
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    (Original post by PlatypusPigeon)
    Outline role of transcription factors which lead to higher expression of PRDM16 in BAT than WAT, i'm sensing that...
    hmmm would this be a good answer to it :-

    certain transcription factors present in BAT initiate the transcription of a gene which codes for the production of PRDM16 by binding to the promoter region in the DNA. the transcribed mRNA is then translated into a functional PRDM16 protein. WAT does not have those transcription factors which are needed for the production of PRDM16 protein.
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    PRDM16 is a protien right ? but article says it is KNOCKED OUT ?! only a gene can be knocked out ? i dont get it ! and is there a hormone or somethign which initiates the production of PRDM16 ..?
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    (Original post by avataraang)
    Hey guys!

    So I have been revising a lot, did lots of past papers, did go through all the spec. points but the one thing always holding me back in biology is the HSW.
    I just can't seem to know what the mark scheme wants, especially if you have to apply your knowledge to an unfamiliar scenario (which always comes up!)
    Can someone please give me advice on how to overcome this tomorrow? I will give rep points to those who give good advice, as I really need an A/A* in tomorrows paper.
    Good luck!
    I know it sounds stupid but all you can really do is practice. There are stock answers you can learn (especially when it applies to ethics or human trials) and other question where you just need to analyse the question carefully. Try and highlight keywords that may give hints to the topic they are talking about and from there write all you can! In many questions it's a 4 or 5 marker so just learn the key points and that should get you through, a lot of answers from markschemes where they give 12 possible answers I don't even recognise (like a H:O ratio in respiration?!). The only other thing you could do is correlate similar questions from each past paper and see what they ask for in each one and make stock answers that can be applied no matter what the situation is.

    Sorry there's no magical answer to it, it's just applying your knowledge and in most cases revising a markscheme which is stupid if you ask me but that's Snab for you!
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    where have you been...............
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    Can someone explain q2a in june 11 and why the shoot goes right and not left to the light.
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    hmmm would this be a good answer to it :-

    certain transcription factors present in BAT initiate the transcription of a gene which codes for the production of PRDM16 by binding to the promoter region in the DNA. the transcribed mRNA is then translated into a functional PRDM16 protein. WAT does not have those transcription factors which are needed for the production of PRDM16 protein.
    Yeah, that sounds like a good answer, can;t think of much more you could say for it! They'd probably link a long question on to it about translation so just blab about ribosomes and trna and how amazing it is :P
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    gonna sound like a very stupid question lol but is ETC process and oxidative phosphorylation the same thing?
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    (Original post by user3456)
    gonna sound like a very stupid question lol but is ETC process and oxidative phosphorylation the same thing?
    ETC and chemiosmosis make up oxidative phosphorylation, may be best not the label them as the same! Without ETC you wouldn't have the energy to move protons down the gradient and form ATP from ATPase :P
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    (Original post by user3456)
    gonna sound like a very stupid question lol but is ETC process and oxidative phosphorylation the same thing?
    oxidative phosphorylation is the major branch out of the two.
    IT INVOLVES ETC and chemiosmosis.
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    (Original post by PlatypusPigeon)
    ETC and chemiosmosis make up oxidative phosphorylation, may be best not the label them as the same! Without ETC you wouldn't have the energy to move protons down the gradient and form ATP from ATPase :P
    i dont get that bit !! why is ENERGY needed to move something DOWN its gradient, isnt it only needed to move somethign AGAINST its gradient ..?hmmmmmmmmmmmm
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    (Original post by rohitbd)
    Can someone explain q2a in june 11 and why the shoot goes right and not left to the light.
    that is EXACTLY what i thought!!! i dont get it surely it makes no sense! I thought maybe they typed the A and B the wrong way round but im sure we would know about it if there was a mistake on a paper
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    (Original post by iesians)
    i dont get that bit !! why is ENERGY needed to move something DOWN its gradient, isnt it only needed to move somethign AGAINST its gradient ..?hmmmmmmmmmmmm
    Oh sozlol, the protons are just pumped from matric to intermembrane space, it's after that they move down the electrochemical gradient. The energy is probably just used to pump them by active transport maybe?
 
 
 
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