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11th January 2012 - 6BIO1 - edexcel biology unit 1

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  • View Poll Results: HOW MUCH DO YOU PEOPLE THINK YOU'LL GET?
    <40
    9
    9.47%
    40-50
    4
    4.21%
    50-60
    28
    29.47%
    60-70
    34
    35.79%
    70-80
    20
    21.05%

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    (Original post by aqua05)
    I dont think sooo
    But im not sure..how about you checking the specification?? (then let me know)

    Well, its not very difficult soo its good if we know it
    Naa we dont need to know it. I asked my teachers and he said we done, so yh....
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    (Original post by arnab)
    Naa we dont need to know it. I asked my teachers and he said we done, so yh....
    aaww..thanks :cool:

    Btw do you know what are the likely topics which would come in this exam ??
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    (Original post by This Honest)
    Hey, I did this paper last Jan and to my surprise, I gained a good grade

    Tips:

    - read the question properly, I can't emphasis this enough
    - pratise drawing diagrams and LABEL even if they don't tell you to
    - know your experiments inside out including control v. It could be like 5 marks. In my exam, I was asked to describe the daphnia experiment, very easy 5 marks for me
    - know how to interpret and describe graphs/tables; graphs WILL always come up and it's pretty tricky but its easy marks if you get the gist of it
    - read your specification to make sure you know everything
    - nail thr MCQ; easy marks
    Oh and check your paper

    Good luck
    Hello there. Please can u help me. I have done the cgp book for biology unit 1 and the student book. I am doing lots of past papers. I am struggling on the vegetable/fruit questions about transport into cells. These questions often involve sucrose solution and potatoes and observing the change in mass. I was thinking does sugar always make water come out/into fruits/vegetables. I was doing a questions and it said explain why putting sugar on strawberries causes water to come out.
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    (Original post by aqua05)
    aaww..thanks :cool:

    Btw do you know what are the likely topics which would come in this exam ??
    can you help with me osmosis in like potatoes/fruits please?
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    (Original post by blue012)
    can you help with me osmosis in like potatoes/fruits please?
    its in the may 2011 paper right ?
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    (Original post by aqua05)
    its in the may 2011 paper right ?
    yes, did u do it?
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    (Original post by blue012)
    yes, did u do it?
    you need help in the whole question or which part is exactly bothering you?
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    (Original post by aqua05)
    you need help in the whole question or which part is exactly bothering you?
    I really didn't know the answer at first. This was the question: using your knowledge of cell transport mechanisms and the properties of water, explain how the juice is formed from the water that came from the fruit.

    I did a similar question with sucrose solution and potatoes. My question is how you supposed to tackle these questions. And does sugar always take water out/into fruit.
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    (Original post by blue012)
    yes, did u do it?
    i think i got what you dont understand..

    Let me start off from the start of the strawberry question..
    The student had the hypothesis that the juice was the sugar dissolved in water & that the water had come from the fruit..so to test this hypothesis
    1. she weighed some fresh strawberries and sprinkled some sugar on it.
    2. one hour later she rinsed off the juice and reweighed the strawberries..


    The bold part of the question is where the key to answer is

    It says she rinsed off the juice. BUT it is likely that when she rinsed off the juice not all the juice or sugar rinsed off...therefore the percentage loss of strawberries is low.

    Someone else may say..too much washing off the strawberries could even mean that the strawberries losses more water like may be when washing..she is washing it in a rough manner thus more water loss.. Resulting in the high percentage loss


    For 1(iii) When sugar is placed on the strawberries..a concentration gradient is created.. The sugar solutes are hypertonic compared to the solution inside the cytoplasm of the strawberries. This would result in water from the cytoplasm of the strawberries which is of high water potential will move outside to the sugar which is of low water potential by osmosis through a semi permeable membrane.

    I hope this helps !:cool:
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    (Original post by aqua05)
    i think i got what you dont understand..

    Let me start off from the start of the strawberry question..
    The student had the hypothesis that the juice was the sugar dissolved in water & that the water had come from the fruit..so to test this hypothesis
    1. she weighed some fresh strawberries and sprinkled some sugar on it.
    2. one hour later she rinsed off the juice and reweighed the strawberries..


    The bold part of the question is where the key to answer is

    It says she rinsed off the juice. BUT it is likely that when she rinsed off the juice not all the juice or sugar rinsed off...therefore the percentage loss of strawberries is low.

    Someone else may say..too much washing off the strawberries could even mean that the strawberries losses more water like may be when washing..she is washing it in a rough manner thus more water loss.. Resulting in the high percentage loss


    For 1(iii) When sugar is placed on the strawberries..a concentration gradient is created.. The sugar solutes are hypertonic compared to the solution inside the cytoplasm of the strawberries. This would result in water from the cytoplasm of the strawberries which is of high water potential will move outside to the sugar which is of low water potential by osmosis through a semi permeable membrane.

    I hope this helps !:cool:
    Thank you very much it does. But does this only happen with sugar or if you put salt on the strawberries will the same happen.
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    (Original post by blue012)
    Thank you very much it does. But does this only happen with sugar or if you put salt on the strawberries will the same happen.
    Yes it will happen as well Same thing
    If you getting confused then just remember when you putting salt/sugar on top of the strawberry..it has NO water thus it is definitely going to be hypertonic Where as the water inside the strawberry contains some water
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    Hiii
    Can someone help me out in the genetic therapy & gaseous exchange bit..pleaseeee!!?!
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    (Original post by aqua05)
    Hiii
    Can someone help me out in the genetic therapy & gaseous exchange bit..pleaseeee!!?!

    Thank you very very much for ur help.

    What dont u get about gene therapy?/gaseous exchange?

    Anyway. Gas exchange is basically (the rate of exchange of 02 and co2 from capillary and alveoli). THe rate of gas exhange/diffusion of gases is faster if there is a large surface area, thin wall, and a high cocentration gradient.

    Our lungs is adapted for fast gas exchange/diffusion because the lung has many alveoli providing a large surface area for gas exchange. Also the alveoli and capillary walls are only one cell thick- this creates a short diffusion pathway. The high concentration gradient is maintained because the alveolus has a good blood supply. Also it is maintained by breathing in and out- this refreshes the air in the alveoli.

    Gene therapy is basically is a way of trying to cure genetic disorders by using alleles (different version of the same gene). It is done by:
    1. Obtaining the normal allele (the one that works)
    2. This allele is going to be introduced into the target cell (the cell with problems)and into the target cell's DNA.
    3. It is introduced by inserting the allele into a vector (liposomes/plasmid
    /viruses)
    4. A nebuliser (spray) can be used to take this up into the cell.

    That is basically what edexcel want us to know. Feel free to ask for more help. Thank you again for that strawberry help!
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    (Original post by blue012)
    Hello there. Please can u help me. I have done the cgp book for biology unit 1 and the student book. I am doing lots of past papers. I am struggling on the vegetable/fruit questions about transport into cells. These questions often involve sucrose solution and potatoes and observing the change in mass. I was thinking does sugar always make water come out/into fruits/vegetables. I was doing a questions and it said explain why putting sugar on strawberries causes water to come out.
    I think you know what it is now
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    (Original post by This Honest)
    I think you know what it is now
    yes thanks
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    [QUOTE=This Honest;35547792]I think you know what it is now [/QUO

    Are u doing unit 1 edexcel biology aswell
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    May 2011 was so hard
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    [QUOTE=blue012;35547841]
    (Original post by This Honest)
    I think you know what it is now [/QUO

    Are u doing unit 1 edexcel biology aswell
    I did it last jan

    I'm doing unit 4 and unit 2 retake :awesome:
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    (Original post by blue012)
    yes thanks
    :rofl:

    I quoted myself, look above for my reply
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    (Original post by blue012)
    Thank you very very much for ur help.

    What dont u get about gene therapy?/gaseous exchange?

    Anyway. Gas exchange is basically (the rate of exchange of 02 and co2 from capillary and alveoli). THe rate of gas exhange/diffusion of gases is faster if there is a large surface area, thin wall, and a high cocentration gradient.

    Our lungs is adapted for fast gas exchange/diffusion because the lung has many alveoli providing a large surface area for gas exchange. Also the alveoli and capillary walls are only one cell thick- this creates a short diffusion pathway. The high concentration gradient is maintained because the alveolus has a good blood supply. Also it is maintained by breathing in and out- this refreshes the air in the alveoli.

    Gene therapy is basically is a way of trying to cure genetic disorders by using alleles (different version of the same gene). It is done by:
    1. Obtaining the normal allele (the one that works)
    2. This allele is going to be introduced into the target cell (the cell with problems)and into the target cell's DNA.
    3. It is introduced by inserting the allele into a vector (liposomes/plasmid
    /viruses)
    4. A nebuliser (spray) can be used to take this up into the cell.

    That is basically what edexcel want us to know. Feel free to ask for more help. Thank you again for that strawberry help!
    This definatelyy helped sooo much !!
    Aahh its okkaayy I'm glad you understood

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