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    Im stuck trying to understand the order of Muscular contraction..

    1. Neuromuscular junction - depolaristation etc. Ca2+ released
    2. Troponin + Tropomyosin stuff where Ca2+ bind to troponin?
    3. then the power stroke?
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    (Original post by KayleighBella)
    guys i've been really ill for the last 6 months and started revision last week. any notes for last minute revision?
    http://www.megaupload.com/?d=7?3ALBJ4C all notes and old spec Q's knock yourself out
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    (Original post by Mcfilly)
    This may sound stupid - but what is leghaemoglobin??
    A protein found in the root nodules of plants where nitrogen fixation takes place, it absorbs oxygen to make the conditions anaerobic.. which is needed for the enzyme nitrogen reductase to work, which allows the plant to fix nitrogen gas, the nitrates are needed for making amino acids.. etc
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    (Original post by catherinegalloway)
    Ahh thankyou very much! that makes alot more sense now haha
    So now, if this comes up in the exam, you'll think of a little buzzing bee and BAM - full marks
    You're welcome!
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    (Original post by atman7)
    http://www.megaupload.com/?d=7?3ALBJ4C all notes and old spec Q's knock yourself out
    apparently the link is unavailable ;S
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    (Original post by HEC14)
    A protein found in the root nodules of plants where nitrogen fixation takes place, it absorbs oxygen to make the conditions anaerobic.. which is needed for the enzyme nitrogen reductase to work, which allows the plant to fix nitrogen gas, the nitrates are needed for making amino acids.. etc
    Thanks
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    Hi, I was just wondering if someone could tell me how much I actually need to know about homeobox genes? Thank you
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    does anyone know what kind of questions they might ask about homeobox genes?
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    Anyone want to explain golden rice to me? I have no clue
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    anyone thing that things like neuromuscular junctions and the power stroke and all of that will come up?
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    (Original post by fortunecookie)
    I think this is a relatively simple question, but could someone explain to me what a transcription factor is? Is it something that causes something to start being transcribed?

    Also, could someone just check I have this right ....
    Bivalent - Two homologous pairs of chromosomes, joined at chiasmata.
    Homologous chromosomes: Two chromatids (Is this the same as sister chromatids?)
    A transcription factor is a protein that binds to a specific DNA sequence therby controlling transcritpion (DNA to mRNA)
    It performs its function by blocking or promoting the binding of RNA polymerase (which is the enzyme that helps add RNA bases to the template DNA strand to make the mRNA strand)

    It also binds to a promotor region on the DNA, they transcritipiton factor therfore regulates the gene expression (that length of DNA)

    Bivalent- correct
    and homologous chromosomes No they are NON sister chromatids, homologoues chromosomes are pairs of chromosomes which code for the same things but are not identical, i.e maternal and paternal chromosomes can be homologous
    X X

    where the red is from mum and has an allele that codes for green eye colour and the black one is from dad and has an allele that codes for blue eye colour etc.

    Where did you come across transcription factor in the book?
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    (Original post by Mcfilly)
    anyone thing that things like neuromuscular junctions and the power stroke and all of that will come up?
    Most people seem to agree there is a good chance that the sliding filament model will come up
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    (Original post by NWA)
    Anyone want to explain golden rice to me? I have no clue
    A few posts above I have explained it, may need to go back 2 pages or so
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    (Original post by NWA)
    Anyone want to explain golden rice to me? I have no clue
    rice is most popular crop in developing countries where people are poor and can't afford a proper diet - bare people go blind from vitamin A deficiency.
    they took phytoene synthetase from daffodils which converts precursor molecules into lycopene, and crt 1 enzyme from bacteria which converts lycopene to another molecule, then there area already enzymes present in the endosperm (rice grain) to convert that to beta-carotene
    beta carotene is a derivative of vit. A and therefore cures vit. A deficiency.

    then a load of rubbish about rights and wrongs of genetic modification, lack of genetic variety if all countries grow this strain, unknown long term effects, etc.
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    difference between tetanus and twitch?
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    List of plant hormones and effects please?
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    (Original post by Arab_Empress)
    A transcription factor is a protein that binds to a specific DNA sequence therby controlling transcritpion (DNA to mRNA)
    It performs its function by blocking or promoting the binding of RNA polymerase (which is the enzyme that helps add RNA bases to the template DNA strand to make the mRNA strand)

    It also binds to a promotor region on the DNA, they transcritipiton factor therfore regulates the gene expression (that length of DNA)

    Bivalent- correct
    and homologous chromosomes No they are NON sister chromatids, homologoues chromosomes are pairs of chromosomes which code for the same things but are not identical, i.e maternal and paternal chromosomes can be homologous
    X X

    where the red is from mum and has an allele that codes for green eye colour and the black one is from dad and has an allele that codes for blue eye colour etc.

    Where did you come across transcription factor in the book?
    Ah right okay. I came across it in homeobox genes, so I'm guessing here it promotes the binding of RNA polymerase.

    Ahh okay, that helps a lot. Thanks
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    (Original post by KayleighBella)
    apparently the link is unavailable ;S
    ah sorry, click on it again in a while and it should be sorted that happens sometimes on the upload site. Sorry about that. I'm missing 3 files too in the pack which I've also attached in this post.
    Attached Files
  1. File Type: docx Revision_Notes_for_Animal_Responses.docx (755.5 KB, 103 views)
  2. File Type: docx Revision_Notes_for_Behaviour.docx (17.5 KB, 130 views)
  3. File Type: docx Revision_Notes_for_Plant_Responses.docx (51.9 KB, 699 views)
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    (Original post by Zeddude)
    Im stuck trying to understand the order of Muscular contraction..

    1. Neuromuscular junction - depolaristation etc. Ca2+ released
    2. Troponin + Tropomyosin stuff where Ca2+ bind to troponin?
    3. then the power stroke?
    Help Please!!

    model answer for Muscular Contraction e.g

    Describe the sequence of events that happens after an impulse arrives at a neuromuscular junction? (9) *made it up*
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    On 'controlling plant growth' on page 224 in the textbook (evaluate experimental evidence blah blah...)

    What exactly are we meant to know about it?? It's the worst spread in the book for explaining things!
 
 
 
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