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    Another hard one
    The effects of polyploidy and fertilisation in flowering plants .
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    (Original post by blink)
    Another hard one
    The effects of polyploidy and fertilisation in flowering plants .
    :eek: :eek: :eek:
    Umm if that turned up on the exam I would not be happy to say the least.
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    :bawling:
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    wouldnt that increase the population as polyploidy is when it occurs large amounts of offspring are produced...or am I wrong.....DAMN
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    (Original post by Bond007)
    wouldnt that increase the population as polyploidy is when it occurs large amounts of offspring are produced...or am I wrong.....DAMN
    Polyploidy is when you have 3 or more complete sets of chromosomes, like polyploidy in wheat.
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    (Original post by Bond007)
    wouldnt that increase the population as polyploidy is when it occurs large amounts of offspring are produced...or am I wrong.....DAMN
    it's when each individual cell in the offspring has >2n chromosomes (4n/6n etc) IIRC.
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    argh so wots polysomy? when non-disjunction occurs and u have just 1 set of complete chromosomes?
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    (Original post by sahsum)
    argh so wots polysomy? when non-disjunction occurs and u have just 1 set of complete chromosomes?
    when you have three or more chromosomes instead of a pair- trisomy 21 is when there are 3x chromosome 21s instead of 2. (trisomy 21 causes Downs' Syndrome)
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    (Original post by sahsum)
    argh so wots polysomy? when non-disjunction occurs and u have just 1 set of complete chromosomes?
    Polysomy's just a general term for having the wrong number of chromosomes. In non-disjunction, the gamete that becomes 2n - 1 after fertilisation is monosomic and thus inviable normally, and the one that's 2n + 1 after fertilisation is trisomic, e.g. Down's syndrome.
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    Oh small cows i can never remember which way round it goes!!

    And what's this aobut wheat???

    And how WOULD it effect it?!?!
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    haploid = n
    diploid = 2n

    polyploid = many n


    I remember -some as "body" or chromosome, so polysomes are many bodies, or many chromosomes.

    this site has some info on polyploidy wrt wheat
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    My latest theory is that Downs Syndrome has two s's in it and polysomy has an s
    polyploidy doensn't

    Actually now you mentioned it diploid/haploid/polyploid is very obvious and i'm positive i've been told before!!
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    ok, its probs way too late for me to be learning meiosis, buts whats the difference between homologous chromosomes and just chromosomes??
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    Homo always means the same
    homosexual
    homogeneous

    homologous means a pair that go together
    e.g. 22 and 22 are homologous
    8 and 8 are homologous
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    (Original post by sahsum)
    ok, its probs way too late for me to be learning meiosis, buts whats the difference between homologous chromosomes and just chromosomes??
    Homologous chromosomes are chromosomes with the same genes but different alleles.
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    I thought homologous were the same alleles and heterozygous were different alleles? Also I assume your doing a different optional module to me, because I'm doing growth developement and reproduction and Polyploidy only comes up in OCR Biology 2.
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    (Original post by Saagar)
    I thought homologous were the same alleles and heterozygous were different alleles?
    thats homo- hetero- zygous
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    ah rite, thnx, well i don't think thats in my paper but at least i won't mess up in case it does.
 
 
 
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