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    (Original post by samwray)
    The january 2010 BY4 paper 10 marker was essentially the same. This was the mark scheme: so no, maybe 3 marks of the possible ones will be down to what you left out
    A. Decomposition / putrefaction; B. Recycling nutrients; C. Breakdown of organic materials into inorganic / suitable e.g.; D. Nitrifying bacteria; E. Nitrosomonas, Nitrobacter; F. ammonium compounds to nitrites; G. nitrites to nitrates; H. ammonium compounds to nitrates if no F/G; I. Nitrogen fixing bacteria; J. atmospheric nitrogen converted into organic nitrogen / e.g.; K. free living azotobacter; L. rhizobium; M. root nodules of (legumes); N denitrification [Max 8] O. encourage aerobic conditions (to stop denitrifyers) / ploughing; P drainage for aerobic conditions to stop denitrifyers; Q grow leguminous crops / add organic waste products / manure / urea etc;[Max 2]
    Thanks a lot man!! Thats really really helpful, ive just read through it and if i can remember correctly ive probably got about 8/9 marks. Hopefully it'll still be enough for the A* 😅😷 i guess all we can do now is wait. Im still not sure about what the answer to intercellular aerobes was though.
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    Has anyone got a copy of the HB4 exam?
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    Hi, for the Nitrogen Cycle essay I wrote ammonia/ammonia ions instead of ammonium ions :/ Will that be accepted?
    Thank you!
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    (Original post by Chirpa)
    Hi, for the Nitrogen Cycle essay I wrote ammonia/ammonia ions instead of ammonium ions :/ Will that be accepted?
    Thank you!
    Sadly. I hate to say this but that will be a contradiction. I made that mistake and got no marks in my mock 😶.. so yh.. but u will have smashed it tho .. dont worry dude ✊
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    (Original post by Mr Average.98)
    Sadly. I hate to say this but that will be a contradiction. I made that mistake and got no marks in my mock 😶.. so yh.. but u will have smashed it tho .. dont worry dude ✊
    Ok thank you I hate to be a pain but if you look at the Gareth Rowlands A2 Biology textbook on pages 52 and 53 they write ammonia as well as ammonia compounds (I can't send a picture so I'll quote)
    "The ammonia formed in putrefaction is converted by nitrification..."
    "Ammonia is converted to nitrite by Nitrosomonas"
    "Atmospheric nitrogen can be converted directly into ammonia"
    "This species of bacteria reduce gaseous nitrogen to ammonia"
    "Atmospheric nitrogen is reduced to ammonia by Rhizobium"
    Like the book writes ammonia, ammonium ions or ammonia compounds

    Also the markscheme from January 2010 means I should be able to get most of the marks without saying ammonium ions?
    A. Decomposition / putrefaction
    B. Recycling nutrients
    C. Breakdown of organic materials into inorganic / suitable e.g.
    D. Nitrifying bacteria
    E. Nitrosomonas, Nitrobacter
    F. ammonium compounds to nitrites
    G. nitrites to nitrates; H. ammonium compounds to nitrates if no F/G
    I. Nitrogen fixing bacteria
    J. atmospheric nitrogen converted into organic nitrogen / e.g.
    K. free living azotobacter
    L. rhizobium
    M. root nodules of (legumes)
    N. denitrification [Max 8]

    Thank you and I hope your exam went well! Onwards and upwards to BY5

    I'm pretty certain I wrote ammonia (not ammonia ions)!
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    (Original post by Chirpa)
    Ok thank you I hate to be a pain but if you look at the Gareth Rowlands A2 Biology textbook on pages 52 and 53 they write ammonia as well as ammonia compounds (I can't send a picture so I'll quote)
    "The ammonia formed in putrefaction is converted by nitrification..."
    "Ammonia is converted to nitrite by Nitrosomonas"
    "Atmospheric nitrogen can be converted directly into ammonia"
    "This species of bacteria reduce gaseous nitrogen to ammonia"
    "Atmospheric nitrogen is reduced to ammonia by Rhizobium"
    Like the book writes ammonia, ammonium ions or ammonia compounds

    Also the markscheme from January 2010 means I should be able to get most of the marks without saying ammonium ions?
    A. Decomposition / putrefaction
    B. Recycling nutrients
    C. Breakdown of organic materials into inorganic / suitable e.g.
    D. Nitrifying bacteria
    E. Nitrosomonas, Nitrobacter
    F. ammonium compounds to nitrites
    G. nitrites to nitrates; H. ammonium compounds to nitrates if no F/G
    I. Nitrogen fixing bacteria
    J. atmospheric nitrogen converted into organic nitrogen / e.g.
    K. free living azotobacter
    L. rhizobium
    M. root nodules of (legumes)
    N. denitrification [Max 8]

    Thank you and I hope your exam went well! Onwards and upwards to BY5

    I'm pretty certain I wrote ammonia (not ammonia ions)!
    You can still write ammonia ions, dont worry. If you look at the June 2014 paper the very first question accepts ammonia ions.
    This is my understanding of it:
    When a plant decomposes, the bacteria deaminate the amino acids because they dont want the NH2 group. I imagine there is a mixture of IONS in the soil, NH2, NH3, NH4. So by saying ammonia ions, I guess it's like saying different ions of ammonia rather than saying ammonium ions.
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    (Original post by matt1997x)
    You can still write ammonia ions, dont worry. If you look at the June 2014 paper the very first question accepts ammonia ions.
    This is my understanding of it:
    When a plant decomposes, the bacteria deaminate the amino acids because they dont want the NH2 group. I imagine there is a mixture of IONS in the soil, NH2, NH3, NH4. So by saying ammonia ions, I guess it's like saying different ions of ammonia rather than saying ammonium ions.
    Thank you for your help! That's put me at ease
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    Guys btw. . What did you put down for the homeostasis question.. the one about beaver, pig and kangaroo rats.And the sheep's environment one. I said its a dry environment than i explained by talking about the figure given in table.. is "dry environment" correct ??


    And than what did you say for explaination for environment of the sheep(using info from table) .. ??
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    (Original post by Spwoosh)
    Thanks a lot man!! Thats really really helpful, ive just read through it and if i can remember correctly ive probably got about 8/9 marks. Hopefully it'll still be enough for the A* 😅😷 i guess all we can do now is wait. Im still not sure about what the answer to intercellular aerobes was though.
    I'm 99% sure intracellular means the bacteria lives inside the cells of a host
    Aerobic is a pretty standard microbiological word, meaning requires oxygen to grow
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    (Original post by Mr Average.98)
    Guys btw. . What did you put down for the homeostasis question.. the one about beaver, pig and kangaroo rats.And the sheep's environment one. I said its a dry environment than i explained by talking about the figure given in table.. is "dry environment" correct ??


    And than what did you say for explaination for environment of the sheep(using info from table) .. ??
    That was a difficult question being it didnt really give you guidance about what to actually put.
    I put the sheep lives in a dry environment because urine conc was higher meaning more water is retained, which suggests water isnt always readily available.
    For the two before that i literally said a beaver lives in water so water is always available and so on. Another ambiguous question.
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    (Original post by matt1997x)
    That was a difficult question being it didnt really give you guidance about what to actually put.
    I put the sheep lives in a dry environment because urine conc was higher meaning more water is retained, which suggests water isnt always readily available.
    For the two before that i literally said a beaver lives in water so water is always available and so on. Another ambiguous question.
    The beaver kangaroo rat one was an exact replica of the textbook but the sheep one threw me off too! Because it asked for it evolved I was like ??? I said the same though but suggested it may have evolutionarily lived in an area of less ready water supply like a hill
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    (Original post by k.russell)
    I'm 99% sure intracellular means the bacteria lives inside the cells of a host
    Aerobic is a pretty standard microbiological word, meaning requires oxygen to grow
    That's what I wrote so let's hope that's right, I think I specified aerobic resp though :/
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    Seriously frustrated about this exam! Did all the past papers and found them pretty easy then for the one that actually matters I struggled with it a fair bit typical wjec tbh most of the questions had really debatable answers so hopefully the markscheme will be lenient with lower grade boundaries!
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    (Original post by Dan_Lumber_)
    Seriously frustrated about this exam! Did all the past papers and found them pretty easy then for the one that actually matters I struggled with it a fair bit typical wjec tbh most of the questions had really debatable answers so hopefully the markscheme will be lenient with lower grade boundaries!
    Im exactly the same .. all past papers and then this comes up
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    What about the question about pH change in different regions? Anyone remember that one?
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    (Original post by Looloowoo)
    What about the question about pH change in different regions? Anyone remember that one?
    Thylakoid space has a lower pH as there is a high concentration of H+
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    Can anyone remember what the had for the 2 questions on the basement membrane part? After the collagen question. Something along the lines on how it looked like the one in the diagram and how it caused kidney failure

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    (Original post by Rhyss01)
    Can anyone remember what the had for the 2 questions on the basement membrane part? After the collagen question. Something along the lines on how it looked like the one in the diagram and how it caused kidney failure

    Posted from TSR Mobile
    Something about the membrane being the molecular sieve. Only meant to let the small molecules though by ultrafiltration. But when it's got the condition it lets the larger molecules through?
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    (Original post by Looloowoo)
    Something about the membrane being the molecular sieve. Only meant to let the small molecules though by ultrafiltration. But when it's got the condition it lets the larger molecules through?
    I said something on the lines of allowing large molecules in but couldn't figure out how blood and protein could cause kidney failure. They expect us to known first year medicine stuff ffs

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    (Original post by Rhyss01)
    I said something on the lines of allowing large molecules in but couldn't figure out how blood and protein could cause kidney failure. They expect us to known first year medicine stuff ffs

    Posted from TSR Mobile
    Yep that's what I said. Just that basically the basement membrane acts as a molecular sieve to prevent large, insoluble molecules from being filtered, but if the membrane is damaged/has disintegrated, the blood and protein aren't filtered so the kidney has to work a lot harder to try and remove these large molecules that shouldn't be there - but that's not a very scientific thing to say so doubt that's right. And I so agree that a lot of it was like 1st year medicine (well I've not done first year med but you know). Like the temperature of action potentials...no idea. Then the sheep one... You have no idea what they want you to write and it's the wjec after all so nothing would surprise me... -_-
    Sorry, rant over
 
 
 
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