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    Hi
    rep if you can help answer this.

    During mitosis at the start during interphase you call them chromosomes until anaphase where you refer to sister chromatids then at telophase they are called chromosomes again,why?
    what is the big diffenece between them?

    Thanks
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    (Original post by hissyfit)
    Hi
    rep if you can help answer this.

    During mitosis at the start during interphase you call them chromosomes until anaphase where you refer to sister chromatids then at telophase they are called chromosomes again,why?
    what is the big diffenece between them?

    Thanks
    Four Chromatids aka tetrad= A pair of chromosome.If that makes any sense
    Basically prior to DNA replication you have single chromatids which later on replicate.
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    During anaphase the chromosomes split into 2. Each half of a chromosome is called a chromatid. In interphase the chromatids are still together to make chromosomes
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    (Original post by hissyfit)
    Hi
    rep if you can help answer this.

    During mitosis at the start during interphase you call them chromosomes until anaphase where you refer to sister chromatids then at telophase they are called chromosomes again,why?
    what is the big diffenece between them?

    Thanks


    In Interphase they look like this:



    Each of p and q is one chromatid, where as p & q together make one chromosome (or a sister chromosome). On the diagram above, there are 2 chromosomes attatched by the centromere as they have been duplicated. They remain like this until anaphase.

    At anaphase they are referred to as the single chromatids because the chromosome has been pulled apart at the centromere by the microfibrils, and is migrating to the poles. Because the chromatids have been pulled apart in anaphase, it would be impossible to refer to them as chromosomes.

    In telophase they are referred to as chromosomes again because this it the last stage of the cycle- the chromatids have been duplicated and have formed new chromosomes. Back to stage 1 so it can all continue again
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    (Original post by racheatworld)
    In Interphase they look like this:



    Each of p and q is one chromatid, where as p & q together make one chromosome (or a sister chromosome). On the diagram above, there are 2 chromosomes attatched by the centromere as they have been duplicated. They remain like this until anaphase.

    At anaphase they are referred to as the single chromatids because the chromosome has been pulled apart at the centromere by the microfibrils, and is migrating to the poles. Because the chromatids have been pulled apart in anaphase, it would be impossible to refer to them as chromosomes.

    In telophase they are referred to as chromosomes again because this it the last stage of the cycle- the chromatids have been duplicated and have formed new chromosomes. Back to stage 1 so it can all continue again
    Aha! thanks I think I get it because at telophase the sister chromatids start to replicate again when they start to go into interphase again.
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    (Original post by hissyfit)
    Aha! thanks I think I get it because at telophase the sister chromatids start to replicate again when they start to go into interphase again.
    Yep! :thumbsup:
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    (Original post by racheatworld)
    Yep! :thumbsup:
    thank you
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    hi

    A replicated CHROMOSOME is 2 SISTER CHROMATIDS JOINED TOGETHER by the centromere



    Hope it helped
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    was this gcse stuff? im screwed for exams this year :/
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    Name:  img006.jpg
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    I drew the diagram and I hope this helps.

    So basically they are called sister chromatids because each of the chromatids have replicated and produced identical chromatid. It's still attached by the centromere so it's still on the same chromosome.
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    (Original post by ash92:))
    hi

    SISTER CHROMATIDS ARE 2 CHROMOSOMES JOINED TOGETHER (CONSISTS OF A CHROMOSOME AND IT'S COPY) by the centromere



    Hope it helped
    I'm pretty sure one chromosome has 2 sister chromatids instead...
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    Sorry but what is chromatin?
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    (Original post by Nash24)
    Sorry but what is chromatin?
    do you mean chromatid as chromatin is completely different thing!
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    (Original post by Sigma5116)
    do you mean chromatid as chromatin is completely different thing!
    I mean chromatin..Because I was reading the stages of meiosis and Prophase is described as:
    'Condensing and supercoiling of chromatin'
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    Basically chromatin is a DNA and other associated proteins which form the chromosome which is highly condensed structure. So chromatins are usually less condensed than chromosome.

    Hope that Helps
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    (Original post by sy_1)
    was this gcse stuff? im screwed for exams this year :/
    I didnt know this when i did GCSE

    Im still trying to get my head round it
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    (Original post by Sigma5116)
    I'm pretty sure one chromosome has 2 sister chromatids instead...
    oooh, crap. yeh sorry it's the other way round. i'll edit that post
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    I also read that during mitosis, the chromatids are called chromsomes when they reach the opposite poles of the cell, i would look this fact up as well, to be sure incase you get a question like this in the exam.
 
 
 
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