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    [QUOTE=Rubyturner94;42908439]can someone go atleast 3 control vari
    Root tip squash:
    MolArity of HCl
    temperature heated to
    Volume of hcl (careful as edexcel won't credit amount usually)

    Totipotency:
    concentrations of growth regulators in agar
    species of plant for each replicate procedure
    temperature
    Light exposure

    Antimicrobial properties:
    temperature
    species of bacterium
    concentrations of each solution the paper discs are soaked in

    Tensile strength:
    Length of fibre
    width of fibre
    mass of fibre

    Nitrate ion concentration
    concentrations of all other mineral ions
    Light exposure of plants
    temperature of plants
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    (Original post by The Assassin)
    I can see them coming up actually - I don't recall seeing regulatory authorities before so I've been making sure I know that.

    Sounds accurate overall, but the only thing I'm not certain about is cohesion-tension/pathways (because that hasn't come up before has it?)
    It hasn't and I have a deep feeling its gonna come up this time round. Take my word for it.
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    (Original post by CoolRunner)
    I will be a happy man if mitosis or totipotency come up.

    I'm placing my bets that plant tensile strength would come up.

    The topics i'm also hedging my bets that are gonna come up are stuff about

    Zoos, regulatory authorities, Ethics, Stem Cells, Plant fertilisation (if we are lucky, mammalian fertilisation), Independent assortment and chiasmata, cohesion-tension, water pathways, Definitions, Bionomial name, Linnaeus, Polygenic Punnet squares and chloroplasts.

    I'm hoping my crazy predictions are correct, so grade boundaries would be lower and It be easy for all of us prepared students (in this forum) get 120ums.
    Linnaeus?

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    (Original post by Randy123)
    could someone please explain species evenness to me
    When the population numbers of each species in the habitat are similar (similar abundances).
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    (Original post by Branny101)
    Linnaeus?

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    Linnaeus = Taxonomy

    Linnaeus is just the guy who come up with it.
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    (Original post by cyberphilic_9999)
    hi guys i dont get why doesn't natural selection occur in humans? i saw this question believe it or not in my textbook??

    thanks
    We adapt for those less fortunate?

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    (Original post by CoolRunner)
    Linnaeus = Taxonomy

    Linnaeus is just the guy who come up with it.
    Ahhhh the Genus - Species thing?

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    (Original post by Branny101)
    Ahhhh the Genus - Species thing?

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    Yup
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    (Original post by Kurraiyo)
    oh okay! so pits are like REDUCED cell walls whereas with plasmodesmata there are no cell walls at all? thanks!!!
    Yes you're right, i've also attached a picture of the page in the revision book which talks about it and there's a diagram, which would help make my explanation a bit more clearer.Name:  Cell wall.jpg
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    what are the risks associated with the methods used to obtain stem cells ?
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    (Original post by CoolRunner)
    It hasn't and I have a deep feeling its gonna come up this time round. Take my word for it.
    hey

    I agree this is defo coming up!

    but i have no idea what to learn, do you have any answers and 'example q's they may ask


    Thanks!! x
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    Don't know what to study in biodiversity part . It is like common sense stuff . I don't think mitosis would come because it came in 3b paper . I hope it won't be difficult , and i hope 5 marks question to write experiment procedure for nitrate would come . Chem unit 2 is more important than bio for me


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    I don't think there are much risks with methods to obtain stem cells but there are risks of using them like , risk of tissue rejection ( not for adult stem cells if nucleus taken from patient ) . Then risk of infection when cells received and there are ethical issues with some cells . It differs from different stem cells


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    (Original post by CoolRunner)
    I will be a happy man if mitosis or totipotency come up.

    I'm placing my bets that plant tensile strength would come up.

    The topics i'm also hedging my bets that are gonna come up are stuff about

    Zoos, regulatory authorities, Ethics, Stem Cells, Plant fertilisation (if we are lucky, mammalian fertilisation), Independent assortment and chiasmata, cohesion-tension, water pathways, Definitions, Bionomial name, Linnaeus, Polygenic Punnet squares and chloroplasts.

    I'm hoping my crazy predictions are correct, so grade boundaries would be lower and It be easy for all of us prepared students (in this forum) get 120ums.
    Could you tell me like a bullet point answer for what happens during crossing-over at the chiasmata?

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    Good luck guys do study well



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    • Welcome Squad
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    Lol, I accidently clicked on the AQA thread and saw magnifiication, and was like woah?!?!!
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    Can someone please explain to me what is the role of the endodermis and the Casparian strip ? Thanks
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    could someone explain to me what biodiversity hotspot is and how is it related to biodiversity
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    (Original post by jooh_23)
    hey

    I agree this is defo coming up!

    but i have no idea what to learn, do you have any answers and 'example q's they may ask


    Thanks!! x
    Probably just the usual, and remember locations of various organelles and parts of the plant (like xylem) they are bound to come up.

    (Original post by Branny101)
    Could you tell me like a bullet point answer for what happens during crossing-over at the chiasmata?

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    For crossing-over.

    1) Before the first meiotic division, homologous pairs of chromosomes pair up.
    2) Chromatids then twist or tie around each other.
    3) Bits or parts of the chromatid break off and join the other chromatid.
    4) Thus a different combination of alleles in the four daughter cells.
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    (Original post by maryam1996)
    Can someone please explain to me what is the role of the endodermis and the Casparian strip ? Thanks
    The role of the endodermis and the Casparian strip is to redirect water and stops the movement of water in the apoplast pathway.

    I hope this helps.
 
 
 
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