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    (Original post by KomradeKorbyn)
    OCR 21st Century Biology B7 GCSE
    Unofficial Mark Scheme

    The part of answers in brackets () refers to extra detail that may not be necessary
    The square brackets [] denote comments on the question or answer

    Question on designing questions to ask about somebody's lifestyle and medical situation in order to create a fitness regime on them:

    Lifestyle (Any two answers):
    Do you smoke?
    What is your BMI?
    What is your diet?
    How often do you drink alcohol?
    Any other valid question about lifestyle

    Medical (Any two answers):
    Do you have any family history of genetic illness (eg diabetes, heart disease, etc)?
    Do you have any personal history of illness (eg diabetes, heart disease, etc)?
    Are you taking any current medication?
    Have you had any recent surgery? What for?
    Any other valid question about medical history

    Question on whether a person should be worried about their weight, what the consequences of this are, how they should improve their weight:
    6 marks

    Yes, because:
    BMI = 31 (rounded), this is in the obese category, (therefore he's well above a healthy weight);
    Body fat = 29%, this is well into the "above average" category for people his age, (so his weight is higher than the average person)

    Consequences of this:
    Heart disease (from fat blocking blood vessels);
    Diabetes (from lowered insulin production or body not recognizing insulin);
    Any other valid consequence of obesity

    To improve:
    He should eat fewer fatty foods, as (these are high in cholesterol which) leads to heart disease (especially in men and especially at his age);
    He should exercise more, as this will make his muscles stronger and make him less fat, (making heart attacks and other diseases less likely);
    Any other valid way of reducing fat

    Question on changes in blood flow before vs during exercise:

    (Any three answers):
    Higher blood flow to muscles (use data from the table) as they are respiring more and so need more oxygen
    Lower blood flow to digestive organs (use data from the table) as blood is needed in other organs for exercise
    Higher overall blood flow (28.0 vs 5.0) as she needs to keep her cells supplied with oxygen + glucose from blood to move about during exercise

    Question on what the blood flow is to her lungs before exercise and why this was not included in the table:

    What the value was:5 (litres per minute)

    Why it was not included:(The heart is a double pump/double circulatory system, and so) the amount of blood going to her lungs is the same as amount of blood going to her body - the blood is deoxygenated after giving its oxygen to cells, and so is pumped to her lungs to become oxygenated, therefore including it in the table was unnecessary.

    Question on using bacteria to produce human insulin:
    6 marks

    [This was almost the exact same question as in a past paper, so I'm just copying in from the official mark scheme]

    [Level 3]
    Answer correctly uses the words ‘isolate’, ‘replicate’, ‘transfer’ and ‘vector’ to explain all of the steps in the process in the correct sequence. All information in answer is relevant, clear, organised and presented in a structured and coherent format. Specialist terms are used appropriately. Few, if any, errors in grammar, punctuation and spelling. (5 – 6 marks)

    relevant points include:

    isolate gene (that codes for) human insulin;
    replicate the gene;
    put gene into a vector;
    such as a virus or plasmid;
    use vector to transfer the gene into bacteria;
    idea that DNA is a universal language that can be interpreted by any organism;
    idea of expression of the gene in the bacteria (to produce human insulin);

    Question on disadvantage of using bacteria for insulin production:

    May cause disease






    Disclaimer: This mark scheme is completely unofficial, and has no affiliation with OCR. Answers may or may not be correct, as they are solely based off of students' personal answers.
    Am i like the only one who completely flopped this exam?
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    (Original post by Ananya._c)
    Last year's exam was beautiful, was it 43 for an A*?

    Posted from TSR Mobile
    Last year was 45, I think this years will defo be lower than that considering how easy last years was in comparision
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    (Original post by KomradeKorbyn)
    Yeah 45 or so seems fair, if a little low, I would say maybe more like 48 A*, as a past paper was 45 A* and was definitely harder than this one
    Added those in, thanks
    48 is highly unlikely
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    Question on what the blood flow is to her lungs before exercise and why this was not included in the table:

    I don't think the justification given was correct. The table said that it only included blood sent from the left ventricle, and blood is sent to the lungs from the right ventricle.
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    Wasn't the last question about insulin production (the 1 mark question after the 6 mark) asking what wasn't a problem/feature regarding the use of microorganisms or something along those lines? All the options they gave you were reasons why microorganisms are ideal for industrial use (e.g. reproduce rapidly, contain plasmids, their biochemistry is simple, etc.) and the only one that wasn't was they cause diseases which isn't true
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    (Original post by iX George Xi)
    Wasn't the last question about insulin production (the 1 mark question after the 6 mark) asking what wasn't a problem/feature regarding the use of microorganisms or something along those lines? All the options they gave you were reasons why microorganisms are ideal for industrial use (e.g. reproduce rapidly, contain plasmids, their biochemistry is simple, etc.) and the only one that wasn't was they cause diseases which isn't true
    Yes. That answer is correct. A lot of people lost marks on that because they didn't read the question properly.


    ⚔🛡⚔~Nothing happens to anyone that he is not fitted by nature to bear - Maximus Decimus Meridius~⚔🛡⚔
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    Political Ambassador
    (Original post by iX George Xi)
    Wasn't the last question about insulin production (the 1 mark question after the 6 mark) asking what wasn't a problem/feature regarding the use of microorganisms or something along those lines? All the options they gave you were reasons why microorganisms are ideal for industrial use (e.g. reproduce rapidly, contain plasmids, their biochemistry is simple, etc.) and the only one that wasn't was they cause diseases which isn't true
    (Original post by MR.ANONYMOUS 786)
    Yes. That answer is correct. A lot of people lost marks on that because they didn't read the question properly.⚔🛡⚔~Nothing happens to anyone that he is not fitted by nature to bear - Maximus Decimus Meridius~⚔🛡⚔

    That may well have been the case, can't remember now but I might have misread it

    What was the correct answer?
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    (Original post by KomradeKorbyn)
    That may well have been the case, can't remember now but I might have misread it

    What was the correct answer?
    You had the correct answer, "it causes diseases." Just the question was wrong
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    C7 Mark scheme anyone?
 
 
 
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