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    Not wanting to sound fresh or anything but how do you click on the notes?
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    Notes for topic 3
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  1. File Type: pdf Topic 3.pdf (395.8 KB, 1188 views)
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    (Original post by Divinedify)
    Notes for topic 3
    Thanks !
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    (Original post by Divinedify)
    Notes for topic 3
    Ahh, Thanks
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    Hey guys!

    I was just reading through some notes I came across here and I saw stuff on water potential/water pathways?
    Also parts of the plant like epidermis and casparian strip? My teacher didn't go through this and I can't find it in the book.

    I checked on the spec and I can't find anything mentioned

    Is this on the spec?
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    (Original post by letsbehonest)
    Hey guys! I was just reading through some notes I came across here and I saw stuff on water potential/water pathways? Also parts of the plant like epidermis and casparian strip? My teacher didn't go through this and I can't find it in the book. I checked on the spec and I can't find anything mentioned Is this on the spec?
    No.
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    (Original post by letsbehonest)
    Hey guys!

    I was just reading through some notes I came across here and I saw stuff on water potential/water pathways?
    Also parts of the plant like epidermis and casparian strip? My teacher didn't go through this and I can't find it in the book.

    I checked on the spec and I can't find anything mentioned

    Is this on the spec?
    Don't think it is - but my teacher said you should learn it and I asked people here and they said that I might as well include it.
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    (Original post by The Assassin)
    Don't think it is - but my teacher said you should learn it and I asked people here and they said that I might as well include it.
    Thanks!!

    Do you have the JAN 13 paper by any chance?
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    (Original post by letsbehonest)
    Thanks!!

    Do you have the JAN 13 paper by any chance?
    There you go
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  2. File Type: pdf Biology QP January Unit 2.pdf (455.1 KB, 336 views)
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    Can anyone help with this : 'explain why the kingdom protoctista has been described as a dumping for species- give examples to illustrate your answer' . I found this but i'm not sure if it answers the question --> because they share common characteristics of plants, animals, and fungi; but they are not placed in any of these kingdoms because they lack one or more of the kingdom's traits.because they share common characteristics of plants, animals, and fungi; but they are not placed in any of these kingdoms because they lack one or more of the kingdom's traits.
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    I don't know if anyone can help by re-attaching Assassin's unit 2 notes again? Tried downloading them a few times, doesn't work, thanks!
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    Hey all,

    In the plant cell wall, cellulose microfibrils are arranged in a crisscross pattern or transversely (in straight lines) in the primary cell wall? In the student book it is said it is deposited transversely, but in the revision guide and in a mark scheme (cannot remember the year) its said that it is arranged crisscrossed. Which is right? And also in the secondary cell wall microfibrils are arranged in sheets?
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    (Original post by Relaxedexams)
    Hey all,

    In the plant cell wall, cellulose microfibrils are arranged in a crisscross pattern or transversely (in straight lines) in the primary cell wall? In the student book it is said it is deposited transversely, but in the revision guide and in a mark scheme (cannot remember the year) its said that it is arranged crisscrossed. Which is right? And also in the secondary cell wall microfibrils are arranged in sheets?
    tbh I don't know but i'd say probably best to go with the markscheme
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    Hi all,
    I came across this statement in the Edexcel AS Biology Student's Book recently (page 171, 'Totipotent animal cells,' Topic 3).

    They basically explain about animal cloning using the embryo splitting technique, and while describing how prize stock are transported around the world cheaply, they say this :

    "Cloned early cattle embryos are placed in the uterus of rabbit 'surrogate mothers', where they begin to develop."

    My doubt is, don't embryos of a certain (mammal)species require specific conditions for development, like
    blood/glucose/oxygen supplies etc?
    And don't different mammals have their own particular physiological adaptations to provide these conditions?
    There's also the chance of rejection of foreign tissue..

    So how can cattle embryos develop inside the uterus of a rabbit??

    Could somebody please explain this?
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    Does anyone have the mark scheme for january 2013, just had my mock
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    (Original post by SKK94)
    Hi all,
    I came across this statement in the Edexcel AS Biology Student's Book recently (page 171, 'Totipotent animal cells,' Topic 3).

    They basically explain about animal cloning using the embryo splitting technique, and while describing how prize stock are transported around the world cheaply, they say this :

    "Cloned early cattle embryos are placed in the uterus of rabbit 'surrogate mothers', where they begin to develop."

    My doubt is, don't embryos of a certain (mammal)species require specific conditions for development, like
    blood/glucose/oxygen supplies etc?
    And don't different mammals have their own particular physiological adaptations to provide these conditions?
    There's also the chance of rejection of foreign tissue..

    So how can cattle embryos develop inside the uterus of a rabbit??

    Could somebody please explain this?
    I remember that we discussed this in class. Apparently the embryos don't grow but are kinda like preserved in the uterus of the rabbits, which are transported with the embryos. When the embryos are needed the rabit is killed and the embryo is taken.

    Posted from TSR Mobile
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    (Original post by Relaxedexams)
    I remember that we discussed this in class. Apparently the embryos don't grow but are kinda like preserved in the uterus of the rabbits, which are transported with the embryos. When the embryos are needed the rabit is killed and the embryo is taken.

    Posted from TSR Mobile
    Thanks! That makes more sense I guess

    Btw, could the killing of rabbits to extract the embryos, be an ethical reason against this technique?
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    (Original post by SKK94)
    Thanks! That makes more sense I guess

    Btw, could the killing of rabbits to extract the embryos, be an ethical reason against this technique?
    We didn't learn about any implications of this method, but I suppose your right. Killing rabbits for our own purpose can be considered unethical.

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    (Original post by Relaxedexams)
    Hey all,

    In the plant cell wall, cellulose microfibrils are arranged in a crisscross pattern or transversely (in straight lines) in the primary cell wall? In the student book it is said it is deposited transversely, but in the revision guide and in a mark scheme (cannot remember the year) its said that it is arranged crisscrossed. Which is right? And also in the secondary cell wall microfibrils are arranged in sheets?
    In the primary cell wall, the microfibrils are oriented in the same direction. Whie in the secondary wall they are arranged at right angles to each other.
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    (Original post by NilFBosh)
    In the primary cell wall, the microfibrils are oriented in the same direction. Whie in the secondary wall they are arranged at right angles to each other.
    That is exactly what is in the student book. In a mark scheme and the revision guide, its given the other way round!!

    Posted from TSR Mobile
 
 
 
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