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    (Original post by Srikmeister)
    HAHA! unless you have seen the paper already or know everything inside out...NOBODY! let us hope it is a paper with low grade boundaries
    Grade boundaries so far have been just 65 and 60 marks for an A!!!
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    20 HOURS REMAIN UNTIL THE EXAMINATION WHICH SHALL DECIDE YOUR FUTURE FIRM OFFER OR NO OFFER OR INSURANCE OFFER OR RESIT

    Although its closer to 14 hours considering a person needs 6 hours of sleep...:eek:
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    (Original post by hellosarah)
    What do we need to know about cyclic AMP, apart from it activates proteins by altering its 3D structure...? Anything elsee??
    If its an enzyme, if you can say that by changing the 3D shape its shape is a better fit for its complementary molecule/substrate
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    (Original post by hellosarah)
    What do we need to know about cyclic AMP, apart from it activates proteins by altering its 3D structure...? Anything elsee??
    Applications - the lac operon:
    Lactose binds to repressor protein changing its shape.
    Lactose is the (inducer) or the (first messenger) xD

    Another one is on the sliding filament model.
    Ca 2+ ions binds to troponin, changing its shape allowing the myosin head to bind with actin filaments and bend.
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    (Original post by greenford)
    So whose actually feeling prepared for this exam?
    Not at all
    I'm trying to be positive though haha, so yeah it's gonna be great!!!! ... :/
    You?
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    (Original post by 786girl)
    please could somone outline the points about NERVIUS SYSTEM its the only topic i feel very weak at. help!!
    The nervous system is split into the CNS (the brain and spinal chord) and the PNS (the neurones that send impulses to and from the CNS)

    The PNS can be split further into the somatic nervous system (voluntary muscles) and the autonomic nervous system (involuntary muscle) which is made up of the parasympathetic nerves (helps relax the body eg when sleeping) and the sympathetic nerves (prepares body for times of stress and danger)
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    (Original post by thecookiem0nster)
    Grade boundaries so far have been just 65 and 60 marks for an A!!!
    True, but it also means you've got to be able to pick up those 65 or so marks to get the grade, and in Unit 5, it is no easy thing. Having said that though, many people get an A in biology so it is certainly possible!
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    (Original post by thecookiem0nster)
    The ocr book really makes it confusing. I was confused too

    Gibberellins cause stem elongation.

    Heres the evidence:

    In the same species, some plants are dwarfs and others are tall plants. It was found that tall plants had more gibberellins than dwarfs. A mutant plant without the gene for creating gibberellin did not grow tall. But when one of it’s branches were grafted onto a normal plant, the graft grew tall. Therefore, gibberellins are responsible for stem elongation
    I thought it was actually to do with having the specific allele that could break down GA20 to GA1 (but yes, higher GA1 conc's in plants = greater stem elongation).

    Eg Dwarf plant has loads of GA20 but no "Le" allele, and therefore cannot break down GA20 to GA1 and grow. (has a recessive "le" allele)

    Tall plant has GA20 and GA1 because it has GA20 to begin with and the "Le" to break it down.

    However if you graft the tall plants lateral stem onto the dwarf plant, it receives the "Le" allele and instantly starts to grow.
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    (Original post by intellectual1)
    x
    :emo:

    I haven't even done any past papers properly!
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    hey does anyone know the grade boundries for f215 specimen paper?
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    Does anyone think abscission's likely to come up? :/y
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    (Original post by 786girl)
    please could somone outline the points about NERVIUS SYSTEM its the only topic i feel very weak at. help!!

    also just as a general question; has there ever been a time when u have WORKED VERY HARD and put it a lot of effort into revising and still get a grade with which u were disappointed? or does hard work always pay off?
    LOL You mean nervous system

    Someone on page 104 did a nice flowchart. The nervous system is split into the central and peripheral. Peripheral contains the somatic and automic components.

    The central nervous system is just the brain and spinal cord. The peripheral neroucs system is all other nerves.

    The autonomic component is split into Sympathetic and parasympathetic

    Symathetic is stimulated for the fight/flight response. The parasympathetic returns the body back to normal. The parasympathetic brings you down like a parachute - that helps me remeber the difference between the two

    I find hard work always pays off
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    (Original post by intellectual1)
    20 HOURS REMAIN UNTIL THE EXAMINATION WHICH SHALL DECIDE YOUR FUTURE FIRM OFFER OR NO OFFER OR INSURANCE OFFER OR RESIT

    Although its closer to 14 hours considering a person needs 6 hours of sleep...:eek:
    I hope I'm not the only one who feels quite annoyed whenever you do this. I manage to get into a nice rhythm of work and relaxation and ask a few questions on this thread, and then get that.

    Please stop.
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    (Original post by DrDr)
    I thought it was actually to do with having the specific allele that could break down GA20 to GA1 (but yes, higher GA1 conc's in plants = greater stem elongation).

    Eg Dwarf plant has loads of GA20 but no "Le" allele, and therefore cannot break down GA20 to GA1 and grow. (has a recessive "le" allele)

    Tall plant has GA20 and GA1 because it has GA20 to begin with and the "Le" to break it down.

    However if you graft the tall plants lateral stem onto the dwarf plant, it receives the "Le" allele and instantly starts to grow.
    Thats right The mutant plant had the homozygous le genotype
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    for hardy weinburg equations, do we have to work out q squared? or will it give us everything including the eq an we just put it in...haha?

    because i don't understand for the example of cystic fibrosis, how q= cfcf and q^2 =cFcf
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    (Original post by rebeccalouise_92)
    for hardy weinburg equations, do we have to work out q squared? or will it give us everything including the eq an we just put it in...haha?

    because i don't understand for the example of cystic fibrosis, how q= cfcf and q^2 =cFcf
    q^2 should be cfcf, books wrong.
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    (Original post by rebeccalouise_92)
    right, can anyone tell me the ratios i need to know for genetics, i can remember dihibrid crosses should be 9:3:3:1 , if not it must be because of epipstasis, any others..
    Dominant epistasis - 12:3:1 or 13:3
    Recessive epistasis - 9:3:4
    Complementary action: 9:7
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    (Original post by rebeccalouise_92)
    for hardy weinburg equations, do we have to work out q squared? or will it give us everything including the eq an we just put it in...haha?

    because i don't understand for the example of cystic fibrosis, how q= cfcf and q^2 =cFcf
    I think it's a mistake in the book, q^2 is cfcf aswell, though why they had to use 2 letters anyway is stupid.
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    Describe the role of the brain and nervous system in the coordination of muscular movement;
    ?
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    (Original post by rebeccalouise_92)
    for hardy weinburg equations, do we have to work out q squared? or will it give us everything including the eq an we just put it in...haha?

    because i don't understand for the example of cystic fibrosis, how q= cfcf and q^2 =cFcf
    q=cf (the recessive allele)
    q^2=cfcf (homozygous recessive)
 
 
 
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