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    Hello just confused about if I'm in the right group, is this thread for ial or gce? I'm doing ial.. if not then is there any thread for it? Thanks in advance
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    Guys I've got a high B in f211, and D's in both of my coursework, Im retaking f212,f214 and f215. If i get a B in f212 and f214 and maybe a high C in f215, Would that be a B overall?
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    What does it mean to 'predict the phenotypic ratios in problems involving epistasis'?
    Does anyone have an example of a past paper q where we've needed to do this?
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    (Original post by Beni24)
    Guys I've got a high B in f211, and D's in both of my coursework, Im retaking f212,f214 and f215. If i get a B in f212 and f214 and maybe a high C in f215, Would that be a B overall?
    I haven't worked it out exactly but from estimating how high the D's were and estimating how high a C/B you'd get this year I think you'd just be short of a B. I think you need to get a B in f215 this year to be sure
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    (Original post by medactuary)
    What does it mean to 'predict the phenotypic ratios in problems involving homeostasis'?
    Does anyone have an example of a past paper q where we've needed to do this?
    Do you mean epistasis rather than homeostasis?
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    Hi can anyone explain to me how light is harvested in the chloroplast membranes? Like involving the photosystems etcI was doing a past paper which had this question, but i didn't quite understand the mark schemeThanks
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    Can someone explain to me how stacking thylakoids into grana possibly increases the surface area!?

    Surely you are decreasing the surface area as thylakoids in the middle of a granum will have the top part of the membrane and the bottom part of the membrane unexposed... Literally nothing on the Internet explains this. Everyone just goes 'stacking thylakoids into grana increases the surface area for light dependent reactions' .. Doesn't explain how the surface area is increased. By looking at it, you can see the surface area clearly decreases from the diagrams of a chloroplast surely?


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    (Original post by Hilton184)
    Can someone explain to me how stacking thylakoids into grana possibly increases the surface area!?

    Surely you are decreasing the surface area as thylakoids in the middle of a granum will have the top part of the membrane and the bottom part of the membrane unexposed... Literally nothing on the Internet explains this. Everyone just goes 'stacking thylakoids into grana increases the surface area for light dependent reactions' .. Doesn't explain how the surface area is increased. By looking at it, you can see the surface area clearly decreases from the diagrams of a chloroplast surely?


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    If we for a moment visualise these thylakoids as cubes as I think it demonstrates my point effectively. Ignore the fact I can't draw haha


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    I'm not doing this exam, but I hope it goes amazingly for all of you! I can't wait to do A2 bio next year, it looks really interesting
    Good luck!!
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    (Original post by Clueless130)
    Hi can anyone explain to me how light is harvested in the chloroplast membranes? Like involving the photosystems etcI was doing a past paper which had this question, but i didn't quite understand the mark schemeThanks
    I think I know the question you mean - from Jan13 - where it wants you to explain basically how the photosystems work using the diagram.

    So what you needed to say was how pigments are arranged in photosystems. These pigments absorb photons/light energy which is used to excite electrons. Also the diagram shows the energy being passed between pigments - the accessory pigments pass the energy they absorb to the 'primary pigment reaction centre' where cholorophyll a is. You could also say how different wavelengths of light are refelected and absorbed by different pigments. Then obviously the QWC terms.

    Not sure if that was what you needed but hope that helps a bit.
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    what are the features of the PCT that allows it to perform its function efficiently?
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    (Original post by Beni24)
    what are the features of the PCT that allows it to perform its function efficiently?
    Microvilli on side of tubule fluid. Opposite side near capillaries also folded. Both increase surface area for transport of ions, glucose, amino acids, etc. Co-transporter proteins for sodium ions with glucose/amino acids. Many mitochondria make lots of ATP for active processes.
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    Hi could someone please send me a link to the past papers for Biology F214 (communication, homeostastis and energy) please!
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    (Original post by Nmak2015)
    Hi could someone please send me a link to the past papers for Biology F214 (communication, homeostastis and energy) please!
    Here you go, http://www.thebiotutor.com/past-papers3.html you can also get them from the ocr website
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    Thank you so much!!
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    Why is nitrogenous wastes such as urea toxic?
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    (Original post by Beni24)
    Why is nitrogenous wastes such as urea toxic?
    Lone pair of electrons on nitrogen atom accepts a hydrogen ion in solution, hence making amines like urea weak bases. This would cause pH to increase and become alkaline. Hence enzymes denature etc.


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    oh yea oops!
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    (Original post by AnnekaChan173)
    I just typed up a huge answer to this but my tablet just killed it for me ok okok
    I'll write it back up when I get home, I have a maths exam today (!) good luck for anyone doing S1, S2 or any other applied modules today!
    hi, sorry would it be possible to explain it again? Thank you and hope your exam went well
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    why does excess paracetamol in the blood lead to liver failure/kidney failure?
 
 
 
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