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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 Snibob)
    I predict 53-54 as it was quite an easy paper
    Most likely not, most people found it quite challenging, probably 47 to 49 for the A*
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    Both moths can pollinate.
    Only species 2 can reach the necter due to the shapes of the beak being complimentry that of the flower (25mm.)
    Mutation caused co-evolution, and talk about how co-elvolution occours.

    50% of it being a sufferer boy.
    24 for the question on the HIV infection.

    Urea is produced by the liver during the metabolic process of breaking down protein.

    sacchromyces cervisiae for the name - spelling doesn't matter as long as it sounds right.

    Insert the plasmid into a bacteria, and grow it in a fermenter. Then take that bacteria and infect the leaves of the plant with it. That acts as vector. Using tissue culture, remove the successful leaves and grow it as a transgenic plant.

    First six marker:
    Primary produces less antibodies as it takes longer for the B-lymphocytes to produce antibodies. However, it leaves memory lymphocytes behind. Therefore in the secondary infection, the memory lymphocytes produces a lot more in the SAME TIME (2 days) before we see the graph falling. IT takes longer for the graph to fall (the antibodies to lower) due to the abudnce of antibodies in the blood.

    Second six marker:
    Sodium Alginate is mixed with Calcium choloride. This forms Calcium Alginate - which is an insoluable bead containing lactase.
    Lactace breaks down lacotose in the milk into galactose.
    These beads are stored in a large continer. Milk is passed though it. Due to calcium Alginate being insoulable, it won't dissolve.
    Keep the milk with the beads for around 15 minutes and at 40 degrees celcius. These are the optimum conditions.
    Then filter the milk from the bottom.
    The milk is now lactose-free.
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    (Original post by stephen1011)
    Both moths can pollinate.
    Only species 2 can reach the necter due to the shapes of the beak being complimentry that of the flower (25mm.)
    Mutation caused co-evolution, and talk about how co-elvolution occours.

    50% of it being a sufferer boy.
    24 for the question on the HIV infection.

    Urea is produced by the liver during the metabolic process of breaking down protein.

    sacchromyces cervisiae for the name - spelling doesn't matter as long as it sounds right.

    Insert the plasmid into a bacteria, and grow it in a fermenter. Then take that bacteria and infect the leaves of the plant with it. That acts as vector. Using tissue culture, remove the successful leaves and grow it as a transgenic plant.

    First six marker:
    Primary produces less antibodies as it takes longer for the B-lymphocytes to produce antibodies. However, it leaves memory lymphocytes behind. Therefore in the secondary infection, the memory lymphocytes produces a lot more in the SAME TIME (2 days) before we see the graph falling. IT takes longer for the graph to fall (the antibodies to lower) due to the abudnce of antibodies in the blood.

    Second six marker:
    Sodium Alginate is mixed with Calcium choloride. This forms Calcium Alginate - which is an insoluable bead containing lactase.
    Lactace breaks down lacotose in the milk into galactose.
    These beads are stored in a large continer. Milk is passed though it. Due to calcium Alginate being insoulable, it won't dissolve.
    Keep the milk with the beads for around 15 minutes and at 40 degrees celcius. These are the optimum conditions.
    Then filter the milk from the bottom.
    The milk is now lactose-free.
    It was 25%
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    (Original post by Amelia Louise)
    Could you send me the mark scheme with all the marks please? Do you know how many i would get?
    Hi! It is question 6 b)* which is near the very end of the paper.

    mark scheme; https://qualifications.pearson.com/c...-June-2014.pdf

    question paper:
    https://qualifications.pearson.com/c...-June-2014.pdf
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    (Original post by MaherPhd)
    The question was about the probability of the offsprings who inherit the disease. Not the probability of getting male offsprings. Also the diease is found on the X chromosome not Y.

    Posted from TSR Mobile
    Nope it clearly said "MALE with haemophilia"
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    Lets start a mark scheme check my thread help build up answers!

    1) Species 2
    b) C
    c) Co-evolution between moths and orchid
    4) Moth gets more nectar to itself/food

    2) Keeps them safe increasing chance of survival
    b) Primrose flowers are short day plants, helps them get pollinated by right insects.
    c) Caterpillars will not get eaten by the prey increasing chance of survival

    UREA is produced in the liver due to the breakdown of excess amino acids

    1st six marker
    primary response first infection of pathogen in body
    immune response is formed as lymphocytes divide and antibodies bind to the antigen
    destroy the pathogen, then memory lymphocytes are in the blood.
    A rapid secondary response is triggered with 2nd infection
    memory lymphocytes
    rapid response of lots of antibodies to destroy the pathogen, most likely before symptoms can be felt.

    HOW IS VEGETARIAN CHEESE PRODUCED? (4 MARKS)
    - made using CHYMOSIN
    - produced by GENETICALLY MODIFIED ORGANISMS
    - CHYMOSIN initiating CLOTTING
    -Chymosin and yeast production in fermenters
    - REDUCED use of RENNET (which is extracted from animals)

    2nd six marker
    lactose converted by lactase to glucose and galactose
    sodium alginate
    calcium chloride
    nylon guaze and syringe beads are put in
    Glucose test strip
    lactose encapsulated in beads
    glucose test strip shows it has been converted to glucose and galactose


    Transgenic plant question
    Restriction enzyme
    Ligases enzyme
    Sticky ends
    Vector
    Infects plant so DNA incorporated into plant
    crown galls

    This is what I have so far, if you could help me remember the question I can write more.
    comment your answers below !!
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    (Original post by oliver45456)
    It was 25%
    Nope 50%, confirmed by a teacher as this type of question was seen in the past paper; i will try to find that.
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    (Original post by __sahar)
    Lets start a mark scheme check my thread help build up answers!

    1) Species 2
    b) C
    c) Co-evolution between moths and orchid
    4) Moth gets more nectar to itself/food

    2) Keeps them safe increasing chance of survival
    b) Primrose flowers are short day plants, helps them get pollinated by right insects.
    c) Caterpillars will not get eaten by the prey increasing chance of survival

    UREA is produced in the liver due to the breakdown of excess amino acids

    1st six marker
    primary response first infection of pathogen in body
    immune response is formed as lymphocytes divide and antibodies bind to the antigen
    destroy the pathogen, then memory lymphocytes are in the blood.
    A rapid secondary response is triggered with 2nd infection
    memory lymphocytes
    rapid response of lots of antibodies to destroy the pathogen, most likely before symptoms can be felt.

    HOW IS VEGETARIAN CHEESE PRODUCED? (4 MARKS)
    - made using CHYMOSIN
    - produced by GENETICALLY MODIFIED ORGANISMS
    - CHYMOSIN initiating CLOTTING
    -Chymosin and yeast production in fermenters
    - REDUCED use of RENNET (which is extracted from animals)

    2nd six marker
    lactose converted by lactase to glucose and galactose
    sodium alginate
    calcium chloride
    nylon guaze and syringe beads are put in
    Glucose test strip
    lactose encapsulated in beads
    glucose test strip shows it has been converted to glucose and galactose


    Transgenic plant question
    Restriction enzyme
    Ligases enzyme
    Sticky ends
    Vector
    Infects plant so DNA incorporated into plant
    crown galls

    This is what I have so far, if you could help me remember the question I can write more.
    comment your answers below !!
    These are my six markers:

    First six marker:
    Primary produces less antibodies as it takes longer for the B-lymphocytes to produce antibodies. However, it leaves memory lymphocytes behind. Therefore in the secondary infection, the memory lymphocytes produces a lot more in the SAME TIME (2 days) before we see the graph falling. IT takes longer for the graph to fall (the antibodies to lower) due to the abudnce of antibodies in the blood.

    Second six marker:
    Sodium Alginate is mixed with Calcium choloride. This forms Calcium Alginate - which is an insoluable bead containing lactase.
    Lactace breaks down lacotose in the milk into galactose.
    These beads are stored in a large continer. Milk is passed though it. Due to calcium Alginate being insoulable, it won't dissolve.
    Keep the milk with the beads for around 15 minutes and at 40 degrees celcius. These are the optimum conditions.
    Then filter the milk from the bottom.
    The milk is now lactose-free.
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    (Original post by stephen1011)
    Nope 50%, confirmed by a teacher as this type of question was seen in the past paper; i will try to find that.
    Well your wrong, in the 2014 paper it was 25% so unlcukyyyyyyy
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    (Original post by oliver45456)
    Well your wrong, in the 2014 paper it was 25% so unlcukyyyyyyy
    I do agree that the answer was 25%, they did not specifically ask for 'JUST OUT OF MALES' they asked from the whole punnet square ;/
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    (Original post by oliver45456)
    It was 25%
    Agreed, it was 25%
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    (Original post by __sahar)
    I do agree that the answer was 25%, they did not specifically ask for 'JUST OUT OF MALES' they asked from the whole punnet square ;/
    And it was 25% ....... as women who have X^H and X^h are just carriers not affected
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    (Original post by __sahar)
    I do agree that the answer was 25%, they did not specifically ask for 'JUST OUT OF MALES' they asked from the whole punnet square ;/



    So the XhY is the boy, who is affected, the XHXh is a girl who is carrying it, the XHY is a boy without it because haemophilia is on the X chromosome, recessive. And XHY is dominant on the X chromosome. XhXH is a girl carrier. Just an explanation, not for you specifically, but anyone who wants it And XHXH is not affected at all
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    Check out the thread 'b3 unofficial mark scheme' created by myself and comment answers so i can add it to the thread!
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    (Original post by oliver45456)
    Well your wrong, in the 2014 paper it was 25% so unlcukyyyyyyy
    Listen, the 2014 paper is different:

    "Using the Punnett square, calculate the probability that individuals C and D could have a child with haemophilia."

    this isn't the same as

    "calculate the probability that individuals C and D could have a BOY with haemophilia."

    A BOY!

    https://fastly.kastatic.org/ka-perse...88f5aabdfb.png
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    (Original post by stephen1011)
    Listen, the 2014 paper is different:

    "Using the Punnett square, calculate the probability that individuals C and D could have a child with haemophilia."

    this isn't the same as

    "calculate the probability that individuals C and D could have a BOY with haemophilia."

    A BOY!

    https://fastly.kastatic.org/ka-perse...88f5aabdfb.png
    It wasn't it said children
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    (Original post by stephen1011)
    Listen, the 2014 paper is different:

    "Using the Punnett square, calculate the probability that individuals C and D could have a child with haemophilia."

    this isn't the same as

    "calculate the probability that individuals C and D could have a BOY with haemophilia."

    A BOY!

    https://fastly.kastatic.org/ka-perse...88f5aabdfb.png
    It is 25%, XhY is a boy with haemophilia and the only way for a boy to have haemophilia. The other combinations were XHXH XhXH and XHY, XhXH is a carrier girl and the other two aren't affected.
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    (Original post by stephen1011)
    Listen, the 2014 paper is different:

    "Using the Punnett square, calculate the probability that individuals C and D could have a child with haemophilia."

    this isn't the same as

    "calculate the probability that individuals C and D could have a BOY with haemophilia."

    A BOY!

    https://fastly.kastatic.org/ka-perse...88f5aabdfb.png
    EXACTLY! A BOY? does it say just probabilities of boy against boy? NO
    its the probability from the whole punnet square .--------.
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    (Original post by oliver45456)
    It wasn't it said children
    Regardless to what it said, only one child HAD haemophilia anyway! The other one, XhXH is a girl and a carrier, the other two aren't affected.
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    (Original post by oliver45456)
    Would i get credited for also mentioning the toxin gene of bacillus thuringiesis
    Dont think so because the plasmid the gave the name of is different to Bt toxin. I think you would have to mention it if it explicitly said so
 
 
 
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