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    I was a bit concerned on question 9, when it said to "use all the information given" to explain the results from electrophoresis.
    It gave the lengths of the primers which attached to R and r and I felt this would have to be mentioned; it also said that shorter fragments move further and didn't identify L and N; these suggested to me that you would have to identify which of L and N was RR and which was rr.

    BUT, the question only told you the lengths of the primers which were used in the PCR, and not the length of the whole alleles; in the electrophoresis I'm fairly sure it was the whole alleles that were separated and not just the parts which the primers bound to?
    Therefore I didn't think it was possible to identify L and N, so I simply said: "L and N are both homozygous, one has two copies of the R allele and one has two copies of r allele, so only one band seen for each, and the alleles are of different lengths so they moved different distances along the gel. All the offspring were heterozygous so they had one R allele and one r allele, so two bands were seen but only of half the width"

    can anyone back me up on this, or explain why I was wrong? It seems that other people identified the recessive allele as the one which moved further.
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    (Original post by eilish1903)
    I wrote about:

    Controlling population grown due to limited resources and human impact on global warmin.
    Controlling human reproduction because of harmful genetic diseases
    Controlling succession to conserve habitats and species and the benifits of this to humans
    Controlling the growth and development of Bacteria due to the increase in antibiotic resistance
    Controlling development of other mammals (hypothesised in a recently published journal that some mammals have the potential to develope and become as intelligent as humans, e.g apes and monkeys and why we should do this [human dominance])
    Wow people have interpreted essay B soooooo differently and looked at it from so many different angles
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    (Original post by lauraedgar)
    Ok all that chromosome stuff makes sense but
    HOW DOES THE PROBE BIND?
    Who knows. Maybe they used heat treatment or alkali to separate
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    Anyone got the exact wording for the essay questions please? Thanks
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    (Original post by talkbiology)
    I was a bit concerned on question 9, when it said to "use all the information given" to explain the results from electrophoresis.
    It gave the lengths of the primers which attached to R and r and I felt this would have to be mentioned; it also said that shorter fragments move further and didn't identify L and N; these suggested to me that you would have to identify which of L and N was RR and which was rr.

    BUT, the question only told you the lengths of the primers which were used in the PCR, and not the length of the whole alleles; in the electrophoresis I'm fairly sure it was the whole alleles that were separated and not just the parts which the primers bound to?
    Therefore I didn't think it was possible to identify L and N, so I simply said: "L and N are both homozygous, one has two copies of the R allele and one has two copies of r allele, so only one band seen for each, and the alleles are of different lengths so they moved different distances along the gel. All the offspring were heterozygous so they had one R allele and one r allele, so two bands were seen but only of half the width"

    can anyone back me up on this, or explain why I was wrong? It seems that other people identified the recessive allele as the one which moved further.
    Correct me if I'm wrong but didn't the question say that the primer binds to a section of DNA that is however many base pairs long. So the numbers they gave did actually represent the length of the fragments with r and R in so you could distinguish between them
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    (Original post by lauraedgar)
    Wow people have interpreted essay B soooooo differently and looked at it from so many different angles
    I feel like I've interpreted it completely wrong.
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    (Original post by talkbiology)
    I was a bit concerned on question 9, when it said to "use all the information given" to explain the results from electrophoresis.
    It gave the lengths of the primers which attached to R and r and I felt this would have to be mentioned; it also said that shorter fragments move further and didn't identify L and N; these suggested to me that you would have to identify which of L and N was RR and which was rr.

    BUT, the question only told you the lengths of the primers which were used in the PCR, and not the length of the whole alleles; in the electrophoresis I'm fairly sure it was the whole alleles that were separated and not just the parts which the primers bound to?
    Therefore I didn't think it was possible to identify L and N, so I simply said: "L and N are both homozygous, one has two copies of the R allele and one has two copies of r allele, so only one band seen for each, and the alleles are of different lengths so they moved different distances along the gel. All the offspring were heterozygous so they had one R allele and one r allele, so two bands were seen but only of half the width"

    can anyone back me up on this, or explain why I was wrong? It seems that other people identified the recessive allele as the one which moved further.
    thats what I said, they were both homozygous and the offspring was heterozygous. theres nothing else you could say unless we missed a vital piece of information
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    (Original post by Usually-Confused)
    Anyone got the exact wording for the essay questions please? Thanks
    B
    The importance to humans of the control of reproduction, development and growth in organisms, including themselves

    I think...
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    (Original post by lauraedgar)
    Ok all that chromosome stuff makes sense but
    HOW DOES THE PROBE BIND?
    Simple.

    God.
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    Has anyone got the link for the Unofficial mark scheme? I've gone back a few pages and can't seem to find anything
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    I thought it said "the primer binds to a 195-bp-long fragment of r" etc. 195bp would be pretty short for a whole allele, and the other one was only 135! even without introns that would only code for a max 45 AA long peptide
    (Original post by lauraedgar)
    Correct me if I'm wrong but didn't the question say that the primer binds to a section of DNA that is however many base pairs long. So the numbers they gave did actually represent the length of the fragments with r and R in so you could distinguish between them
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    [QUOTE=eilish1903;57126985]
    (Original post by lauraedgar)
    Ok all that chromosome stuff makes sense but
    HOW DOES THE PROBE BIND?[/QUOTE{

    Simple.

    God.
    Can you imagine if AQA decided to go all evangelical with their mark scheme this year XD
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    For 10a i wrote about homeostasis of glucose and temperature, neurones, hormones, chemoreceptors, tropisms, photosynthesis, transpiration, heart, lungs, immunity and plants absorbing ions.
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    [QUOTE=lauraedgar;57127053]
    (Original post by eilish1903)

    Can you imagine if AQA decided to go all evangelical with their mark scheme this year XD
    Get the mark if u have a religious examiner. It's a marking guideline and it's not technically wrong 😂
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    (Original post by studenntt)
    How is muscular contraction affected when Ca 2+ ion channels close (4)
    I spoke about no calcium ions to move troponin from actin binding site? looking at other people's answers on here that seems to be wrong?
    I wrote about that's as well!
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    (Original post by talkbiology)
    I thought it said "the primer binds to a 195-bp-long fragment of r" etc. 195bp would be pretty short for a whole allele, and the other one was only 135! even without introns that would only code for a max 45 AA long peptide
    I don't think it matters if its not the entire gene it still shows that the fragment contained R was shorter than the fragment that contained r (i think it was that way round) so from the electrophoresis you could work out which was which
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    (Original post by Ashleyb96)
    Has anyone got the link for the Unofficial mark scheme? I've gone back a few pages and can't seem to find anything
    I haven't seen an "official" unofficial mark scheme (lmao)
    but a couple of us have shared all our answers

    See post #2084 page 105 http://www.thestudentroom.co.uk/show...06391&page=105

    and post #2034 page 102 http://www.thestudentroom.co.uk/show...ge=102&x=0&y=0
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    (Original post by lauraedgar)
    B
    The importance to humans of the control of reproduction, development and growth in organisms, including themselves

    I think...
    Thankyou! How did you find the paper?
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    (Original post by Usually-Confused)
    Thankyou! How did you find the paper?
    Really good overall. There are obviously some questions where I will have missed marking points or made stupid mistakes but I think I got the general idea with every question
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    How? Just because the primer used was shorter doesn't mean the whole allele was shorter (does it? idk halp)
    (Original post by lauraedgar)
    I don't think it matters if its not the entire gene it still shows that the fragment contained R was shorter than the fragment that contained r (i think it was that way round) so from the electrophoresis you could work out which was which
 
 
 
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