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    (Original post by InItToWinItGetIt?)
    Yeah that makes sense, I'm not thinking straight today! :mad:

    It depends on how much time you have till the exam. I just went through it today, but I have a Unit 4 exam for bio, and a Psychology exam the day before Unit 5.

    I haven't done any past papers for this unit yet. But from a quick scan of the June 2010 paper, it seems the synoptic stuff is saved for the article. I've attached it for you, if you want a look yourself.
    Do you have a mark scheme for this that you could attach? Thanks
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    (Original post by Adam9)
    Do you have a mark scheme for this that you could attach? Thanks
    http://www.scribd.com/doc/46124423/B...-Scheme-Unit-5

    (Original post by monkeyytastic)
    Thank you um not sure but in the article it mentions stem cells and things, and says manufactore red blood cells rather than simply proteins so thought it might need to be in
    I can't find in the article where it mentions stem cells for EPO production
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    2 things guys!

    firstly, I noticed in last june's exam that any material from hte specification that is relevant to the article, they leave it just for the article.. therefore we are to expect lots on eye and the brain in the first part of the exam, and respiration and muscles in the article question..

    secondly, was there a unit 5 sitting in january 2010? because i can't find it anywhere... there was a unit 4 sitting, so why there wasn't a unit 5 one? :/
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    The paper is marked out of 90 right? Does anyone know what you have to get out of 90 (roughly - I know it changes year to year) to get a grade B???
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    (Original post by LibbyU)
    The paper is marked out of 90 right? Does anyone know what you have to get out of 90 (roughly - I know it changes year to year) to get a grade B???
    Check the grade boundaries off the edexcel website. I can't remember what it is off the top of my head.
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    Does anyone have links to the old SNAB papers? They used to be on the Edexcel site but it seems they've removed them :/
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    (Original post by gildartz)
    Does anyone have links to the old SNAB papers? They used to be on the Edexcel site but it seems they've removed them :/
    http://www.edexcel.com/i-am-a/teache...astpapers.aspx

    Click on GCE (curriculum 2000) for 2008 onwards of the old spec and the ''Summer 2007 and earlier'' link
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    Hey,

    i got given some qustions for the article (without a mark scheme) and not sure how to answer them?

    state the stages that occur in a specific immune response when a known pathogen invades the body (starting with phagocytes going to the nearest lymph node)

    i started writiung this:
    Firstly, there is activation of the T helper cells, bacterium with antigens on the surface is engulfed my macrophage, this then becomes an antigen presenting cell.
    It binds to complementary CD4 on the T helper cells. This then stimulates the cells to divide into clones of active T helper cells and clones of T helper memory cells.
    Then undergoes clonal selection in which the antigen binds to complementary receptor on the B cell, B cell becomes antigen presenting, then binds to activated T helper cell which produces cytokines which stimulates the B cell to differentiate and divide into B memory cells and b effector cells, the B effector cells differientiate into plasma cells producing antibodies.
    Then the antibodies bind to bacteria with antigen on its surface, labelling them, then antigens bind to antigen receptor on the macrophage. Macrophage engulfs the antibodies and bacterium. Lysosomes fuse with the vacuole, releasing digestive enzymes that destroy the pathogen.

    BUT then wasn't sure is it just the T killer cell response??

    how is it that the body picks up and utilises oxygen, so it can be shuttled from the lungs for use in the tissues?

    wasn't sure what there asking, do we talk about, ventilation, inhalation etc? and then respiration?
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    (Original post by InItToWinItGetIt?)
    http://www.edexcel.com/i-am-a/teache...astpapers.aspx

    Click on GCE (curriculum 2000) for 2008 onwards of the old spec and the ''Summer 2007 and earlier'' link
    Thanks a lot
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    (Original post by monkeyytastic)
    Hey,

    i got given some qustions for the article (without a mark scheme) and not sure how to answer them?

    state the stages that occur in a specific immune response when a known pathogen invades the body (starting with phagocytes going to the nearest lymph node)

    i started writiung this:
    Firstly, there is activation of the T helper cells, bacterium with antigens on the surface is engulfed my macrophage, this then becomes an antigen presenting cell.
    It binds to complementary CD4 on the T helper cells. This then stimulates the cells to divide into clones of active T helper cells and clones of T helper memory cells.
    Then undergoes clonal selection in which the antigen binds to complementary receptor on the B cell, B cell becomes antigen presenting, then binds to activated T helper cell which produces cytokines which stimulates the B cell to differentiate and divide into B memory cells and b effector cells, the B effector cells differientiate into plasma cells producing antibodies.
    Then the antibodies bind to bacteria with antigen on its surface, labelling them, then antigens bind to antigen receptor on the macrophage. Macrophage engulfs the antibodies and bacterium. Lysosomes fuse with the vacuole, releasing digestive enzymes that destroy the pathogen.

    BUT then wasn't sure is it just the T killer cell response??

    how is it that the body picks up and utilises oxygen, so it can be shuttled from the lungs for use in the tissues?

    wasn't sure what there asking, do we talk about, ventilation, inhalation etc? and then respiration?
    I just had a big debate with myself whether to use the term ''macrophage'' or ''phagocyte'' lol. The green Edexcel book uses macrophage, while the purple revision guide and CGP book uses phagocyte.

    I'm gonna go with phagocyte. Phagocyte is the general term for any WBC that engulfs stuff and then displays the antigens on it's surface. Macrophages are a type of phagocyte.

    I'd mention both T cell response and B cell response. I'd also mention just in case, that T-killer cells kill infected cells by releasing enzymes that make pores in those cells. Hence fuilds enter and cell swells and bursts. But your answer would no doubt be well enough for 5-6 marks.
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    (Original post by InItToWinItGetIt?)
    I just had a big debate with myself whether to use the term ''macrophage'' or ''phagocyte'' lol. The green Edexcel book uses macrophage, while the purple revision guide and CGP book uses phagocyte.

    I'm gonna go with phagocyte. Phagocyte is the general term for any WBC that engulfs stuff and then displays the antigens on it's surface. Macrophages are a type of phagocyte.

    I'd mention both T cell response and B cell response. I'd also mention just in case, that T-killer cells kill infected cells by releasing enzymes that make pores in those cells. Hence fuilds enter and cell swells and bursts. But your answer would no doubt be well enough for 5-6 marks.
    THnk you very much!!!

    I was also wondering could you help with this one?
    Explain how an adenovirus would be recognised and destroyed by the immune system? 4 marks

    The body can have antibodies in the body which are complementary to the antigens on the surface of the adenovirus so will recognise them. Antibodies will bind to the antigens, which is complementary to the antigen binding site on the antibody, which then bind to the antibody receptor on the macrophage which engulfs the adenovirus, and destroys it.
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    (Original post by InItToWinItGetIt?)
    I just had a big debate with myself whether to use the term ''macrophage'' or ''phagocyte'' lol. The green Edexcel book uses macrophage, while the purple revision guide and CGP book uses phagocyte.

    I'm gonna go with phagocyte. Phagocyte is the general term for any WBC that engulfs stuff and then displays the antigens on it's surface. Macrophages are a type of phagocyte.

    I'd mention both T cell response and B cell response. I'd also mention just in case, that T-killer cells kill infected cells by releasing enzymes that make pores in those cells. Hence fuilds enter and cell swells and bursts. But your answer would no doubt be well enough for 5-6 marks.
    The general answer for the immune response is usually always the same.... you need to pay attention to what they are asking.... i.e. whether you need to talk about cell mediated or humoral response....

    virus-infected cells, bacterium infected cells and cancer cells are dealt with by the Killer T cells that, like you said, release chemicals (called perforins) that lead to pores in the cells thereby causing these cells to burst and thus die... (NB: cell lysis may not be the best option because the viral particles inside the cell may actually be released and thus can go on and infect other cells... but hey )

    in the article:

    “There’s a problem with repeated dosing: your body will build
    antibodies against the virus that inserts the gene into your cells, so if you give another injection
    with the same virus, your body’s immune system may very well wipe out the virus before it can
    deliver its genes,”

    in this case, the cell isnt actually infected but the virus particles in the blood stream that were going to infect the cells are detected by the B lymphocytes that then undergo clonal selection to produce the desired antibodies
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    (Original post by InItToWinItGetIt?)
    Check the grade boundaries off the edexcel website. I can't remember what it is off the top of my head.
    do you know where I can find them on the edexcel site? I have looked but can't find them thanks
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    (Original post by monkeyytastic)
    THnk you very much!!!

    I was also wondering could you help with this one?
    Explain how an adenovirus would be recognised and destroyed by the immune system? 4 marks

    The body can have antibodies in the body which are complementary to the antigens on the surface of the adenovirus so will recognise them. Antibodies will bind to the antigens, which is complementary to the antigen binding site on the antibody, which then bind to the antibody receptor on the macrophage which engulfs the adenovirus, and destroys it.
    The q asks how the adenovirus would be recognized... like i said in my post above:

    1) macrophages (or even better, dendritic cells) detect these viruses as FOREIGN because they have proteins on their protein coat...
    2) engulfed and presented on the cell surface membrane of the APC
    3) a T helper cell is activated when it attaches and binds to these complementary receptors. It then divides by clonal selection into clones of T helper cells and memory T helper cells
    4) When a B lymphocyte comes in contact with these viruses they attach and bind to them with the cell surface receptors. When the T helper cell with complementary receptors releases the cytokines the B lymphocytes divide and differentiate into plasma cells that secrete antibodies that are specific and complementtary to the antigen
    5) Antigen bind to these viruses and form immune complexes... basically immobilising them... these immune complexes are destroyed by macrophages
    6) If there is a second encounter with the antigens the secondary immune response is involved and the B lymphocytes release antibodies again and immobilisies the viruses
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    (Original post by chemdweeb1234)
    The general answer for the immune response is usually always the same.... you need to pay attention to what they are asking.... i.e. whether you need to talk about cell mediated or humoral response....

    virus-infected cells, bacterium infected cells and cancer cells are dealt with by the Killer T cells that, like you said, release chemicals (called perforins) that lead to pores in the cells thereby causing these cells to burst and thus die... (NB: cell lysis may not be the best option because the viral particles inside the cell may actually be released and thus can go on and infect other cells... but hey )

    in the article:

    “There’s a problem with repeated dosing: your body will build
    antibodies against the virus that inserts the gene into your cells, so if you give another injection
    with the same virus, your body’s immune system may very well wipe out the virus before it can
    deliver its genes,”


    in this case, the cell isnt actually infected but the virus particles in the blood stream that were going to infect the cells are detected by the B lymphocytes that then undergo clonal selection to produce the desired antibodies
    Yeah you're right. In the case of the bold bit, it's the humoral response that is required.

    (Original post by monkeyytastic)
    THnk you very much!!!

    I was also wondering could you help with this one?
    Explain how an adenovirus would be recognised and destroyed by the immune system? 4 marks

    The body can have antibodies in the body which are complementary to the antigens on the surface of the adenovirus so will recognise them. Antibodies will bind to the antigens, which is complementary to the antigen binding site on the antibody, which then bind to the antibody receptor on the macrophage which engulfs the adenovirus, and destroys it.
    I'd go with the same answer. Antigens recognised as non-self.... etc. etc.

    (Original post by LibbyU)
    do you know where I can find them on the edexcel site? I have looked but can't find them thanks
    http://www.edexcel.com/iwantto/Pages...oundaries.aspx
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    (Original post by chemdweeb1234)
    The q asks how the adenovirus would be recognized... like i said in my post above:

    1) macrophages (or even better, dendritic cells) detect these viruses as FOREIGN because they have proteins on their protein coat...
    2) engulfed and presented on the cell surface membrane of the APC
    3) a T helper cell is activated when it attaches and binds to these complementary receptors. It then divides by clonal selection into clones of T helper cells and memory T helper cells
    4) When a B lymphocyte comes in contact with these viruses they attach and bind to them with the cell surface receptors. When the T helper cell with complementary receptors releases the cytokines the B lymphocytes divide and differentiate into plasma cells that secrete antibodies that are specific and complementtary to the antigen
    5) Antigen bind to these viruses and form immune complexes... basically immobilising them... these immune complexes are destroyed by macrophages
    6) If there is a second encounter with the antigens the secondary immune response is involved and the B lymphocytes release antibodies again and immobilisies the viruses
    thank you, with the frist question i asked, it uses the word known pathogen, does that mean the body recognises it as foreign? of is it asking about a secondary immune response?
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    heres a question directed at the article i thought people might what to have a go at :
    using examples from the article discuss the benefits and risks of using gene therapy to prevent muscle atrophy:

    so far this is what i came up with:
    Benefits: useful in the sick and elderly prevent muscle being broken down which makes it easy to recover after being ill has don’t have to build up muscle, and means elderly people become less frail. Prevents diaphragm wasting when on a respirator.
    When athletes miss training muscle doesn’t breakdown so less difficult to start up again later.
    Disadvantages: unfairness in sports
    Once inserted gene can’t be switched which lead to over expression
    People replace gene therapy wiyj training which is dangerour as muscle does not mean stay fit, as exercise increase blood supply to muscles and increases number of mitochondria in the muscle cells.
    thanks
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    Thanks! would you mind explaining to me what UMS is? im really confused about it.
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    How is everyone revising for this exam? I'm predicted a C, but desperately need a B in order to get into uni, it's the only thing holding me back because apart from my predicted C in biology im predicted 2 A's in my other subjects I just don't know where I'm going wrong... I seem to get C's every time in biology! can anyone give me any advice?

    For my biology exams I revise mainly from the textbook, reading it thoroughly and making sure I understand it then make notes on it. I also do all the past papers available and mark them using the mark scheme and revise from these. I also watch videos on youtube. Even when I feel like I know the textbook and specification inside out and understand it all I still only get C's! where am I going wrong? and how can I improve my time management in the exams?

    would be grateful for any advice, just feel like no matter how hard I try im getting nowhere
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    Hey you seems to have really good questions based on article/.?.do you have more could you please send it to me?
    or post it here?
    (Original post by monkeyytastic)
    Hey,

    i got given some qustions for the article (without a mark scheme) and not sure how to answer them?

    state the stages that occur in a specific immune response when a known pathogen invades the body (starting with phagocytes going to the nearest lymph node)

    i started writiung this:
    Firstly, there is activation of the T helper cells, bacterium with antigens on the surface is engulfed my macrophage, this then becomes an antigen presenting cell.
    It binds to complementary CD4 on the T helper cells. This then stimulates the cells to divide into clones of active T helper cells and clones of T helper memory cells.
    Then undergoes clonal selection in which the antigen binds to complementary receptor on the B cell, B cell becomes antigen presenting, then binds to activated T helper cell which produces cytokines which stimulates the B cell to differentiate and divide into B memory cells and b effector cells, the B effector cells differientiate into plasma cells producing antibodies.
    Then the antibodies bind to bacteria with antigen on its surface, labelling them, then antigens bind to antigen receptor on the macrophage. Macrophage engulfs the antibodies and bacterium. Lysosomes fuse with the vacuole, releasing digestive enzymes that destroy the pathogen.

    BUT then wasn't sure is it just the T killer cell response??

    how is it that the body picks up and utilises oxygen, so it can be shuttled from the lungs for use in the tissues?

    wasn't sure what there asking, do we talk about, ventilation, inhalation etc? and then respiration?
 
 
 

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