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Edexcel B3 unofficial markscheme 19th June 2017 Watch

  • View Poll Results: What mark do you think you got?
    55+
    23
    8.65%
    47-54
    98
    36.84%
    39-46
    88
    33.08%
    30-38
    40
    15.04%
    22-29
    12
    4.51%
    Under 22
    5
    1.88%

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    (Original post by milesdavis)
    what do you guys predict the grade boundary to be?
    last year it was 47 for an A* as the test was harder im predicting maybe 45 for A* and 41 for an A.
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    (Original post by Aaron jhooty)
    Restriction enzyme
    Ligases enzyme
    Sticky ends
    Vector
    Infection of plant
    Incorporation of DNA into plant
    I also mentioned crown galls
    What did u mention?
    I thought you didnt have to write about the enzymes and gene mixing because it already said in the question that the gene was taken out and put into the plasmid which produces a toxin so all i wrote about was that plant leaf discs are infected with it and grow into plants which each contain the toxin making gene and the plasmid acts as a vector when creating the transgenic plants
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    Did anyone get the sacchromyces cervisiae for the yeast question?
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    (Original post by spikelee3138)
    Did anyone get the sacchromyces cervisiae for the yeast question?
    yes
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    (Original post by Zaki1039)
    I thought you didnt have to write about the enzymes and gene mixing because it already said in the question that the gene was taken out and put into the plasmid which produces a toxin so all i wrote about was that plant leaf discs are infected with it and grow into plants which each contain the toxin making gene and the plasmid acts as a vector when creating the transgenic plants
    Your right
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    The last page was a myth because I did not revise enzymes for some idiotic reason. Hoping for low gb most of it was ok tho.
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    (Original post by spikelee3138)
    Did anyone get the sacchromyces cervisiae for the yeast question?
    I wrote sacchromyces but not cervisiae. Do you think I will still be able to get the mark?
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    (Original post by Yateschloe00)
    I wrote that there's a 25% of a child with the disease and 50% chance of a boy with the disease. I put both.
    I don't think putting both will get you a mark.
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    (Original post by MIKESPIKE10)
    i'm sure
    thanks
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    (Original post by Aaron jhooty)
    Restriction enzyme
    Ligases enzyme
    Sticky ends
    Vector
    Infection of plant
    Incorporation of DNA into plant
    I also mentioned crown galls
    What did u mention?
    Did you say that you use agrobacterium tumefacien specifically?
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    (Original post by Zaki1039)
    I thought you didnt have to write about the enzymes and gene mixing because it already said in the question that the gene was taken out and put into the plasmid which produces a toxin so all i wrote about was that plant leaf discs are infected with it and grow into plants which each contain the toxin making gene and the plasmid acts as a vector when creating the transgenic plants
    Yeah I got the same I didn't write about makin the toxin I wrote How it's put in the plant as a vector and plants can breed and create the same gene as stuff like that
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    (Original post by Zaki1039)
    I thought you didnt have to write about the enzymes and gene mixing because it already said in the question that the gene was taken out and put into the plasmid which produces a toxin so all i wrote about was that plant leaf discs are infected with it and grow into plants which each contain the toxin making gene and the plasmid acts as a vector when creating the transgenic plants
    Technically yes ur correct I just wrote it to ensure I didn't miss easy marks, I mentioned all the stuff u said to I.E. infection of plants to incorporate gene into plant and crown gall and how it can be used as a vector, I used agrobacterium tumfacians as an example
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    (Original post by Aaron jhooty)
    Technically yes ur correct I just wrote it to ensure I didn't miss easy marks, I mentioned all the stuff u said to I.E. infection of plants to incorporate gene into plant and crown gall and how it can be used as a vector, I used agrobacterium tumfacians as an example
    Would i get credited for also mentioning the toxin gene of bacillus thuringiesis
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    (Original post by jashab14)
    Everyone in my school got 24 but to be honest, they didn't make it clear as to whether the 0.925% and 0.625% was of the entire 16,000 or out of the two 8,000 groups
    agree it was badly worded
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    (Original post by Aaron jhooty)
    Yeah that's right, the primary response bit was mentioning first infection of pathogen in body, and an immune response is formed as lymphocytes divide and antibodies bind to the antigen and destroy the pathogen, then memory lymphocytes are in the blood.
    A rapid secondary response is triggered with 2nd infection due to the memory lymphocytes which produce a rapid response of lots of antibodies to destroy the pathogen, most likely before symptoms can be felt. I don't think there was anything else to say to get 6/6?
    Thankyou - that's what I put!
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    (Original post by Pastels123)
    I wrote sacchromyces but not cervisiae. Do you think I will still be able to get the mark?

    Don't see why you wouldn't because tbh how on earth do edexcel expect us to memorise that haha?
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    (Original post by Nafisah1001)
    It asked for the difference between the two groups, and if you don't half it you're assuming both groups has 16000 people rather than 8000
    The question said they were in two equal groups
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    (Original post by Jadeelmazi)
    Thankyou - that's what I put!
    No problem
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    (Original post by Nafisah1001)
    It asked for the difference between the two groups, and if you don't half it you're assuming both groups has 16000 people rather than 8000
    Did the question state the group was exactly split into 8000, 8000? If not then you could have any amount in each group , you Gould have 10,000 in one and 6000 in the other
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    (Original post by oliver45456)
    Would i get credited for also mentioning the toxin gene of bacillus thuringiesis
    Potentially, it's technically relevant.
 
 
 
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