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    (Original post by Brad0440)
    I was going to do one for that after my chemistry exam on Wednesday. :P
    Do you mind, by looking at the sheet you made making predictions on what will come up in unit 4. thanks
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    How confident are people with this exam, on a scale of 1 to 5?

    5 - Really Confident................1 - Going to Fail

    I feeling "3" at the moment
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    (Original post by EstebanK0)
    Year '10 '11 '11 '12 '12 '13
    A* 63 58 60 67 63 67
    A 58 54 56 62 58 63
    B 53 50 52 57 53 59
    C 49 46 48 52 49 55
    D 45 42 45 47 45 51
    E 41 38 42 43 41 47
    U 0 0 0 0 0 0

    Raw mark grade boundaries. Apologies for the formatting.
    Weird thing is i found the jan 2013 much harder than the previous years yet huge grade boundary. Anyone else?
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    i really dont know how to answer those big global warming questions! can someone help me out? like what we have to know?
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    (Original post by raves)
    i really dont know how to answer those big global warming questions! can someone help me out? like what we have to know?
    • causes
    • greenhouse effect
    • greenhouse gases
    • effects: think about this in terms of social, economical, and evironmental (thats the most important one)
    • evidence for it
    • evidence against it
    • scientific community and their involvement in getting this evidence
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    Can anyone explain the clonal selection
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    (Original post by SKK94)
    They are asking for overall percentage increase from Jan to May.
    So first, find the values of NPP at each month
    Jan = 1 gm^2
    May = 11 gm^2
    Percentage increase = (difference/ initial value) x 100
    = (11 - 1)/10 x 100
    = 1000 %


    haha..

    sucha simple one ehh. thanks again, wonder how many more times ive to thank you
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    (Original post by [email protected])
    It asked for the percentage increase of NPP between jan to may so at jan NPP was 1 and in May its 11 so percetnage change is 11-1=10 and 10/1 *100 which = 1000%

    thanks
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    (Original post by raves)
    i really dont know how to answer those big global warming questions! can someone help me out? like what we have to know?
    Carbon dioxide and methane are greenhouse gases (methane has a stronger greenhouse effect)
    Absorb ifra red radiation
    Traps heat
    Warms Earth, greenhouse effect
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    Does anyone have any advice on time keeping?
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    (Original post by Brad0440)
    The crosses means that the specification point IS in the past paper.

    As the headings aren't very clear, I'll put a list of them here in the same order as they are on the image:

    Chloroplasts in photosynthesis
    Photosynthesis
    -Energy from light to break up water
    -Hydrogen stored as a fuel in glucose by combination with CO2 and releasing O2
    Light dependent reactions
    ATP as energy
    Light independent reactions
    Use of light independent reaction products
    NPP + GPP
    Trophic levels
    Carbon cycle
    Biotic and abiotic factors
    Ecology study
    Niche
    Succession
    Global warming cause and effect
    Temperature and enzyme activity
    Temperature and development
    Evidence for global warming
    Global warming controversial evidence
    Change in allele frequency due to mutation/natural selection
    Speciation
    Antibitoic resistance
    Accepting evidence due to peer review etc.
    Nature of the genetic code
    Protein synthesis
    Exons
    DNA profile
    PCR
    Gel electrophoresis
    Bacteria Vs. viruses
    Decomposition by micro-organisms
    Barriers to infection
    Specific bacterial and viral diseases (i.e. TB and HIV)
    Non-specific immune system
    Cells etc. within the immune system (e.g. T-cells, antibodies, etc.)
    Immunity
    Antibiotic types (static/cidial)
    Antibiotic effects ('Clear zone' practical)
    Death-forensics

    Sorry about the poor hand-writing, and I can't guarantee that I haven't missed any questions out. Also, the last column is just my predictions as to what could come up in this paper and can be ignored.


    Hard work!

    now im giving all my attention to ur predictions
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    (Original post by swahmad)
    Carbon dioxide and methane are greenhouse gases (methane has a stronger greenhouse effect)Absorb ifra red radiationTraps heatWarms Earth, greenhouse effect
    thank yoou
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    (Original post by nukethemaly)
    • causes
    • greenhouse effect
    • greenhouse gases
    • effects: think about this in terms of social, economical, and evironmental (thats the most important one)
    • evidence for it
    • evidence against it
    • scientific community and their involvement in getting this evidence
    thank yyoooou
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    what are the sequence of events that take place when someone is infected with HIV?
    i.e. the non specific immune response
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    Sorry about this, but what have people learnt for the specific immune response? I have learnt the process from the CGP revision guide, but I am worrying that it is too basic.

    Thanks a lot!
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    (Original post by Selym95)
    Sorry about this, but what have people learnt for the specific immune response? I have learnt the process from the CGP revision guide, but I am worrying that it is too basic.

    Thanks a lot!
    the official textbook is quite good for it, so have a look through that!
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    (Original post by amber109)
    what are the sequence of events that take place when someone is infected with HIV?
    i.e. the non specific immune response
    There are three stages that follow the initial infection:

    The acute phase:
    -HIV antibodies appear in the blood (after 3-12 weeks)
    -The virus enters and destroys T-helper cells to replicate, causing a net loss of T-helper cells and an increase in HIV
    -A few weeks after the initial infection, the T-killer cells recognise and destroy infected T-helper cells

    The chronic/latent phase:
    -The action of T-killer cells keeps in check the number of HIV in the body, but cannot completely eliminate them
    -During this phase, opportunistic diseases (like TB) can reactivate and other illnesses like colds can take longer to get over than normally, due to a decreased immune system

    The disease phase:
    Eventually, the number of HIV in the body overwhelms the immune system and causes the T-helper cell count to drop dramatically, severely damaging the immune system and indicating the onset of AIDS



    (Original post by nukethemaly)
    OCR B by any chance?
    No actually, I'm doing OCR chemistry A.
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    What's the difference between ATP-ase and ATP- synthase? I know they're both enzymes in the thylakoids . but is there any difference? The mark schemes sometimes say ATP-ase and other times it says ATP synthase?
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    What is the humoral immune response? Does it also have a different name?
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    (Original post by tsr1)
    What's the difference between ATP-ase and ATP- synthase? I know they're both enzymes used in the the thylakoids in grana... but is there any difference? The mark schemes sometimes say ATP-ase and other times it says arp synthase?
    ATP synthase is the protein that is responsible for creating ATP in the mitochondria. ATPase is any enzyme/protein that uses ATP as a power source to produce function
 
 
 
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