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    (Original post by adilh301)
    considering that could be used to deconstruct your whole phosphate head deflecting water molecules argument id say its worth it but yeah ill leave this 2 mark grey area be now :P.
    Meh, they could hit the tails too. My teacher said 'collide with the hydrophobic parts of the membrane', so I just interpreted her wrong too.
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    (Original post by racheatworld)
    I know OCR don't tend to be the best at wording questions, but they would definitely not just put "cell surface membranes" and just because it is within a question about onion epidermal cells expect you to read their minds and assume that they are talking about plant cells? They would word it clearer than that, I'm sure they would put something at the very least "explain how water moves across these cell membranes" which would then lead you to look back and see they were talking about the onion cells. Don't worry, I'm not stressed, I'm just sure I read the question as "cell surface membranes"
    Haha relax. Im on your side, but Im sure hes not going to give up either!
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    (Original post by DonFahad)
    Meh, they could hit the tails too. My teacher said 'collide with the hydrophobic parts of the membrane', so I just interpreted her wrong too.
    which in an earlier post you said you couldn't possibly have done but in relation to your above post im giving up now lolz no need to get worked up over a 2mark grey area.
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    (Original post by adilh301)
    and osmosis alone only shows one route mentioning aquaporins is out of the specification.
    its a grey area
    its either symplast or vacuolar or pinocytosis+osmosis
    the only thing thats for sure is if you wrote osmosis alone you didn't get 2 marks.
    im not sure but don't the symplast/vacuolar pathways go through plasmodesmata and not the cell surface membrane. The only way water can move though the membrane is through diffusion/osmosis as it is a small molecule. I guess the second mark is for describing that osmosis is the diffusion from high to low water potential across a partially permeable membrane but i may be wrong
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    (Original post by adilh301)
    which in an earlier post you said you couldn't possibly have done but in relation to your above post im giving up now lolz no need to get worked up over a 2mark grey area.
    I said I couldn't have heard her wrong. Heard =/= interpreted. you fails.
    Secondly, I'm not the worked up one lmfao, you are, you are replying to every post that disagrees with you.
    Thirdly, I finished this argument ages ago, only for you to bring it back up because I made a slight error.

    Chin up mate
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    This exam, I felt, was a lot harder than any of the mocks!

    What was the answer to the question about the steam?
    And also why a plant that has its stem cut survives longer?

    I got something in my eye in the exam, couldn't see for like 5 minutes and had to be taken out of the sports hall to get it out but didn't get extra time... (not that I expected I would) then ran out of time

    Oh dear, it was such a train wreck.
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    (Original post by LVN93)
    This exam, I felt, was a lot harder than any of the mocks!

    What was the answer to the question about the steam?
    And also why a plant that has its stem cut survives longer?

    I got something in my eye in the exam, couldn't see for like 5 minutes and had to be taken out of the sports hall to get it out but didn't get extra time... (not that I expected I would) then ran out of time

    Oh dear, it was such a train wreck.
    It was definitely harder than any exam in the past, apart from the very last one, june 2010, which was pretty hard too.

    Welcome to TSR, and don't worry, there are many resit opportunities.

    The steam one, I said something like, the xylem cells are all in one straight column, which is lignified and dead, meaning that no water molecules can diffuse out of the column.

    The plant which survives longer was the question my teacher word-for-word predicted, its because there are small air bubbles trapped inside, in the last few CM of the stem, so you cut them off to remove the trapped air, then immediately put it under water, so that no more air is trapped. When air is trapped inside, this prevents water from reaching the leaves, and so prevents photosynthesis occurring. No photosynthesis = no energy, = plant dying.
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    (Original post by LVN93)
    This exam, I felt, was a lot harder than any of the mocks!

    What was the answer to the question about the steam?
    And also why a plant that has its stem cut survives longer?

    I got something in my eye in the exam, couldn't see for like 5 minutes and had to be taken out of the sports hall to get it out but didn't get extra time... (not that I expected I would) then ran out of time

    Oh dear, it was such a train wreck.
    So did i! it's my third time taking the exam - i got my script back as i felt i did well in the last one to see my problem is assuming the examiner knows things XD
    But i thought it was a lot harder than any of the past papers, i didn't know about cytokinesis at all!
    the one with the steam? i put that as the xylem is lined with lignin, which is flexible, so it won't collapse in on itself and then about water potential and the xylem being a constant end to end tube.
    i put for the stem cut question that the water doesn't need to travel through the root or root cortex so it the water would travel up the xylem easier by cohesion. XD
    hahaha! that sucks! i ran out of time too but just cause i did XD
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    (Original post by Sohailahmed)
    I got 1650, dunno if i'm right
    yes okay but did you have to round off?? coz it said write an estimate and everone here seems to be rounding off the last no..so does that mean i will get it wrong? regardless of the exact figure..im talking about rounding off bit
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    Did anyone else find that on a few questions they only wrote one line and there was four lines to write on? I got really worried id not written enough.
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    (Original post by LVN93)
    This exam, I felt, was a lot harder than any of the mocks!

    What was the answer to the question about the steam?
    And also why a plant that has its stem cut survives longer?

    I got something in my eye in the exam, couldn't see for like 5 minutes and had to be taken out of the sports hall to get it out but didn't get extra time... (not that I expected I would) then ran out of time

    Oh dear, it was such a train wreck.
    They always put those types of qs to catch you out but its okay because many people probably got them wrong.
    Steam is because they have no end walls and because of them being lignified
    Steam is cut to remove air blocked xylem!

    I'm just annoyed because no cardiac stuff came up
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    (Original post by mud)
    yes okay but did you have to round off?? coz it said write an estimate and everone here seems to be rounding off the last no..so does that mean i will get it wrong? regardless of the exact figure..im talking about rounding off bit
    They will most probably accept a range.

    i
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    for the steam one i put xylem vessels cells are dead with no cytoplasm or organelles to obstruct the steams path, with no end walls between cells - therefore it just flows straight through. guess this must be right then..

    for the shoot, i put decreases distance (from water to cell) so photosynthesis can occur, but didn't think of the bubble bit - think ill still get 1 mark?

    Don, what did you put for the cell division (diff between plants n animals?) 2 mark question?
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    Ahh this is such a huge thread, and my PC is realllyyy slow! So I was wondering what everyone answered for the "how transcription helps water movement up the plant" and "neutrophils" questions.

    Cheers guys!
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    (Original post by Sama93)
    They will most probably accept a range.

    i
    thanks! check ur inbox
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    LOL at everyone getting worked up about 2 mark questions.

    to all the newbies, welcome to TSR :rolleyes:
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    (Original post by DonFahad)
    It was definitely harder than any exam in the past, apart from the very last one, june 2010, which was pretty hard too.

    Welcome to TSR, and don't worry, there are many resit opportunities.

    The steam one, I said something like, the xylem cells are all in one straight column, which is lignified and dead, meaning that no water molecules can diffuse out of the column.

    The plant which survives longer was the question my teacher word-for-word predicted, its because there are small air bubbles trapped inside, in the last few CM of the stem, so you cut them off to remove the trapped air, then immediately put it under water, so that no more air is trapped. When air is trapped inside, this prevents water from reaching the leaves, and so prevents photosynthesis occurring. No photosynthesis = no energy, = plant dying.
    s**t! i wrote about trapped air but then i crossed it out and wrote a whole load of nonsense! instead, i wrote about how the bottom part is dead so it cant transport air therefore we cut off the dead part aggh
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    is there any mark scheme thats going to be posted up??
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    (Original post by blahblah772)
    yeah man I think the histamine question was asking about receptor mediated endocytosis... taking in the histamine into the cell and causing the smooth muscle to contract
    For the histamine question i wrote about receptors and target cell rubbish
    found this exam sooooooooo hard!
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    (Original post by CullenLoverX)
    LOL at everyone getting worked up about 2 mark questions.
    Ah, but two marks could be the difference between an A and a B
 
 
 
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