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    (Original post by ibysaiyan)
    Hi there,Lets see...
    Err do you mean like hpw do the gametes cross link with each other for instance in the punnet square?
    Oh I think i get it now...
    Sex linkage is where you get diseases or "Characteristics" exclusively on one type of chromosome.Say haemophilia which is an 'X' chromosome recessive allele.Note: X^hX^h fetus doesn't survive.
    Now one would think why don't women show these "characteristics" but just carry them? Reason well as we know our beautiful mums carry two X's as a result one dominates the other allele.
    Hope I made it clear on the sex-linkage bit? tbh I had it at first confused with the autosomal linkage.


    Genetic linkage:Is the estimate of how the recombination of alleles or genes undergoes during meiosis or to be specific inheritance.

    So the frequency of the crossing over or re-shuffling depends on how close the alleles/genes are.
    Say for example: We observe Gene A and Gene B together always.This probably means they are situated in the same chromosome close to each other so when segregation occurs there is "less" chance of them being displaces in the newly formed hybrid.
    For genes being physically apart there will be a greater or more likely chance of them being re-shuffled.

    Hope I made sense. =}

    Hi sorry i rarely post on here but I read it all and well done to you all you work so very hard, i hope it pays off for each and every one of you!!


    just a quick question, so genetic linkage refers to in meiosis where chiasma happens? and how the sister chromotids will cross over? So ones that are together (on the same chromosome) will always appear together?????

    can someone help me cos im FREAKING OUT!!! AAAH
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    could anyone also help me with how you identify and sequence genes? there are two arent there? and one uses PCR? i think one is the chain-termination method.

    could anyone also help me with epistasis? like the different types?? what goes on? ALL I REMEMBER IS ABOUT RABBITS????

    and if ANYONE can help me with how you isolate enzymes then PLEASE DO!! the books seem to contradict themselves??

    sorry i know this is alot to ask but i am reeaaaally worried now!!!!
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    (Original post by aiden1234)
    Hi sorry i rarely post on here but I read it all and well done to you all you work so very hard, i hope it pays off for each and every one of you!!


    just a quick question, so genetic linkage refers to in meiosis where chiasma happens? and how the sister chromotids will cross over? So ones that are together (on the same chromosome) will always appear together?????

    can someone help me cos im FREAKING OUT!!! AAAH
    Hi there: No to be exact we call it crossing over and to answer your question again ti all depends nothing is for certain but there is a greater frequency for genes or alleles which actually appear to be at quite a far distance in the chromatins such that once the recombinations takes place the newly di-hybrid chromosome might have them totally displaced.
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    (Original post by aiden1234)
    could anyone also help me with how you identify and sequence genes? there are two arent there? and one uses PCR? i think one is the chain-termination method.

    could anyone also help me with epistasis? like the different types?? what goes on? ALL I REMEMBER IS ABOUT RABBITS????

    and if ANYONE can help me with how you isolate enzymes then PLEASE DO!! the books seem to contradict themselves??

    sorry i know this is alot to ask but i am reeaaaally worried now!!!!
    From what I can recall the way you could "read" a genome of an organism is by electrophoresis and there is also another route which is done by reverse transcription such as one in the production of Insulin.
    Let me go through with you on electrophoresis.I am typing it as at the minute.
    .....
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    (Original post by Sakujo)
    Muscle work=half of module 4:yep:
    Yeay =}
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    thankyou so much!!!
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    Guys we don't have to know about genetic diseases do we? Only the concepts behind them.
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    so genetic linkage is just when alleles say hair colour and eye colour for example are on the same chromosome then they will be inherited together??

    and sex linkage is when genes are located on the sex chromosome and therefore ones on the Y only males will get it? and ones on the X, females will have less chance as they have two X's?
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    (Original post by aiden1234)
    could anyone also help me with how you identify and sequence genes? there are two arent there? and one uses PCR? i think one is the chain-termination method.

    could anyone also help me with epistasis? like the different types?? what goes on? ALL I REMEMBER IS ABOUT RABBITS????

    and if ANYONE can help me with how you isolate enzymes then PLEASE DO!! the books seem to contradict themselves??

    sorry i know this is alot to ask but i am reeaaaally worried now!!!!
    It sure is a lot to ask at once but anyway I am not losing anything but gaining and so are the rest of us.
    Ok:
    Electrophoresis: Basically fragments of DNA are run through a tube which has potential difference running through it consisting of agarose gel.

    First of all we break,suspense and precipitate dna.Next Primers along with enzymes and dna bases are added to the solution to make up more genetic material i.e to have more copies of dna so that the original one can be kept safely at one side.Primers are needed because these act as start-points for DNA-polymerase enzyme to initiate PCR.Next "Tagged" nucleotides are added.These nucleotide have certain properties:
    These are marked in different colored say orange for Guanine and Blue for Thymine (just a example).
    Also these nucleotide are doubly De-oxidized.Such that no further base pair rule applies after these "tagged bases" have formed. =}
    After all this lengthy process we get all fragments of DNA starting from One base to who knows what.
    These DNA fragments are added to the tube.As we all know dna is acidic such that it carries Negative charge due its Phosphate back bone.So all fragments head towards positive side.So a longer fragment would take more time i.e slower compared to its shorter counterpart.
    At the end of the tube is a laser gun which fires through oncoming bases.Computer calculates the time it took to reach their along with speed of fragment .
    This is how genome sequencing is done. =} The PCR which you talked about is one of the sub-process of genetic engineering.
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    (Original post by aiden1234)
    so genetic linkage is just when alleles say hair colour and eye colour for example are on the same chromosome then they will be inherited together??

    and sex linkage is when genes are located on the sex chromosome and therefore ones on the Y only males will get it? and ones on the X, females will have less chance as they have two X's?
    Err basically sex linkage is the dependency of inheriting a character depending on the combination of Chromosomes.Say for example Haemophile which we know is an "X" recessive disease.So for females there is no X^hX^h fetus but there are carriers X^h X^H on the other hand sadly for males since they have one X chromosome :/ they have greater chance of suffering the disease.The Possible genotype for them are:
    X^H Y
    X^h Y
    Again sex linkage is just the linking of these "alleles" which are specific to certain chromosomes, see what I mean?
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    (Original post by ibysaiyan)
    It sure is a lot to ask at once but anyway I am not losing anything but gaining and so are the rest of us.
    Ok:
    Electrophoresis: Basically fragments of DNA are run through a tube which has potential difference running through it consisting of agarose gel.

    First of all we break,suspense and precipitate dna.Next Primers along with enzymes and dna bases are added to the solution to make up more genetic material i.e to have more copies of dna so that the original one can be kept safely at one side.Primers are needed because these act as start-points for DNA-polymerase enzyme to initiate PCR.Next "Tagged" nucleotides are added.These nucleotide have certain properties:
    These are marked in different colored say orange for Guanine and Blue for Thymine (just a example).
    Also these nucleotide are doubly De-oxidized.Such that no further base pair rule applies after these "tagged bases" have formed. =}
    After all this lengthy process we get all fragments of DNA starting from One base to who knows what.
    These DNA fragments are added to the tube.As we all know dna is acidic such that it carries Negative charge due its Phosphate back bone.So all fragments head towards positive side.So a longer fragment would take more time i.e slower compared to its shorter counterpart.
    At the end of the tube is a laser gun which fires through oncoming bases.Computer calculates the time it took to reach their along with speed of fragment .
    This is how genome sequencing is done. =} The PCR which you talked about is one of the sub-process of genetic engineering.
    mmmmaaaah!!! thankyou sooooo much ! if theres any justice you'll get a A***
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    (Original post by Sakujo)
    Guys we don't have to know about genetic diseases do we? Only the concepts behind them.
    Actually we do. Some which I can remember off are: Sickle Cell anemia,CFTR.
    Sickle cell nothing to go i much detail just know that substitution of one base causes it which as result has a greater impact on the tertiary structure of the haemoglobin.
    Not to remember: The base glutmate is replaced by valine.
    Again its to do with one being hydrophobic and other hydrophilic can't remember which way it is tbh so which causes all haems to glue onto each other.
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    (Original post by aiden1234)
    mmmmaaaah!!! thankyou sooooo much ! if theres any justice you'll get a A***
    Hey np. =}
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    (Original post by ibysaiyan)
    Actually we do. Some which I can remember off are: Sickle Cell anemia,CFTR.
    I'd rep you if you could do a summary of the basics.
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    does this look correct?

    Many genes can control the same characteristic. This can be because the allele of one gene masks the expression of the alleles of other genes – this is called epistasis.
    For example:
    If you have two copes if a recessive epistatic allele then this masks the expression of the other gene.

    If you had the recessive gene being g (for green coat) and then a person had BBgg then the person would have a green coat. However if you had BBGg then they would have a blue coat.

    If you cross a homozygous recessive parent with a homozygous dominant parent then you will get 9:3:4 with the 4 being the recessive epistatic gene.
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    (Original post by Sakujo)
    I'd rep you if you could do a summary of the basics.
    I dont remember much but anyways lets see:
    CFTR: (Cystic fibrosis conductance trans membrane regulator).
    Is a genetic disease which if i remember correctly is caused by a faulty recessive allele version on chromosome 9?
    The implications of it are: Low immune system along with short breath and excessive mucus secretion ( to an extent that a person might drown).
    How it all works? Here is how:
    On a normal human being the cells in the lung region have special protein channels which actively throw out K+ ions out as a result of which we get a water potential gradient.The ore K's out the more water potential increases, this causes excess water to be secreted out of the cell and mix-up with the mucus.S you can figure out now wheat happens to a faulty version? No channel proteins made
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    (Original post by aiden1234)
    does this look correct?

    Many genes can control the same characteristic. This can be because the allele of one gene masks the expression of the alleles of other genes – this is called epistasis.
    For example:
    If you have two copes if a recessive epistatic allele then this masks the expression of the other gene.

    If you had the recessive gene being g (for green coat) and then a person had BBgg then the person would have a green coat. However if you had BBGg then they would have a blue coat.

    If you cross a homozygous recessive parent with a homozygous dominant parent then you will get 9:3:4 with the 4 being the recessive epistatic gene.
    Err from what you have defined I think its right. As epistasis is the control of the appearance of a character "phenotype" by more than one genes. For example color coat in mice or any organism.The bit I am not sure of is this:

    If you had the recessive gene being g (for green coat) and then a person had BBgg then the person would have a green coat. However if you had BBGg then they would have a blue coat.
    Wouldn't the coat color be Blue anyway? as Dominant alleles always "show their appearance" ?
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    (Original post by ibysaiyan)
    Err from what you have defined I think its right. As epistasis is the control of the appearance of a character "phenotype" by more than one genes. For example color coat in mice or any organism.The bit I am not sure of is this:


    Wouldn't the coat color be Blue anyway? as Dominant alleles always "show their appearance" ?
    yeah im really confused, does this make sense?:

    if the g gene is recessively epistatic then it will overide the BB or the bb or the Bb and will be shown anyway?
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    (Original post by aiden1234)
    yeah im really confused, does this make sense?:

    if the g gene is recessively epistatic then it will overide the BB or the bb or the Bb and will be shown anyway?
    It depends say if the recessive allele acts as the "on" switcher(hypostatic i think) then yes.
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    (Original post by ibysaiyan)
    It depends say if the recessive allele acts as the "on" switcher(hypostatic i think) then yes.
    ace thankyou so much for your help

    someone up there said about repping you? how do i do this? i want to thankyou for all your help!!!
 
 
 
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