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AQA BIOL5 Biology Unit 5 Exam - 22nd June 2011 Watch

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    is electrophoresis used in gene sequencing and for genetic fingerprinting?...
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    (Original post by angel1992)
    can anyone explain the difference between endotherms and ectotherms in terms of their activity and body temperature- can you relate it to metabolism etc??
    Ecotherms (reptiles, fish): Can't control their internal body temperature, they can only attempt to control in by behaviour (basking in the sun)

    Internal temperature depends on surrondings (external temp)

    Activity level also depends on external temp, activity level higher at higher temps, lower at lower temps.

    They have a variable metabolic rate, generate little heat themselves.

    Endotherms (mammals, birds): Can control body temp internally by homeostasis and can control temp by behaviour too.

    Internal temp less affected by surrondings, (within certain limits).

    Activity level also largely independent of external temp, active at any temp (within certain limits)

    Constantly high metabolic rate, generate a lot of heat from metabolic reactions.
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    (Original post by appleschnapps)
    ... That would be me getting a little copy and paste happy. Ignore the partial fragments at 3 and 5.
    Thank you, but could you please help me out with this one?

    Question 9biii.

    Again, i get why the 3kb is there, but why the one? How can you work that out from gel? I know the answer, but don't understand how you work it out.

    http://store.aqa.org.uk/qual/gce/pdf...5-W-SQP-07.PDF QP

    http://store.aqa.org.uk/qual/gce/pdf...5-W-SMS-07.PDF MS

    Thanks
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    (Original post by Tericon)
    Ecotherms (reptiles, fish): Can't control their internal body temperature, they can only attempt to control in by behaviour (basking in the sun)

    Internal temperature depends on surrondings (external temp)

    Activity level also depends on external temp, activity level higher at higher temps, lower at lower temps.

    They have a variable metabolic rate, generate little heat themselves.

    Endotherms (mammals, birds): Can control body temp internally by homeostasis and can control temp by behaviour too.

    Internal temp less affected by surrondings, (within certain limits).

    Activity level also largely independent of external temp, active at any temp (within certain limits)

    Constantly high metabolic rate, generate a lot of heat from metabolic reactions.
    CGP. I'm using that too. It's great!
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    (Original post by sarahlovesleon)
    i find synapses and action potentials harder!
    For me they are pretty easy maybe because I like the topic.. And genetics was okay until chapter 16.4 -.- today I've done a moved with the specimen paper and that's the only bit where I was struggling on so now I'm focusing on revising it and then prepare everything that I can for the synoptic essay!
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    (Original post by blackberryaddict)
    CGP. I'm using that too. It's great!
    I don't use anything else...aside from tsr
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    (Original post by Tericon)
    Can someone please help me with 10ci and ii? I know the answer, but don't understand how graph shows this? And what on earth does 'heat-killed' mean?

    http://store.aqa.org.uk/qual/gce/pdf...5-W-SQP-07.PDF QP

    http://store.aqa.org.uk/qual/gce/pdf...5-W-SMS-07.PDF MS
    I had no idea what heat killed was either when I did it, just assumed it literally meant heat killed.

    For Ci, it's active transport. Active transport is caused by a protein and if that protein is heated, it becomes denatured. Hence why no value at heat killed.

    For ii, the mutation has to be more pumps. A more permeable membrane would do nothing, as IAA is moving from high conc. to low conc. therefore ATP must be used. DNP stops the pump from working, you can tell because it returns to the level of the wild type without the mutation.
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    This part of the course is really easy to me in content but the exam is really hard. It's annoying, I'm not sure if my cramming is best spent on the content or answering essays and what not.

    Either way, I'll be glad when its over. Biology has been such a thorn in my side. So many assessments, half of which I resat... just one more!
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    (Original post by Tericon)
    Thank you, but could you please help me out with this one?

    Question 9biii.

    Again, i get why the 3kb is there, but why the one? How can you work that out from gel? I know the answer, but don't understand how you work it out.

    http://store.aqa.org.uk/qual/gce/pdf...5-W-SQP-07.PDF QP

    http://store.aqa.org.uk/qual/gce/pdf...5-W-SMS-07.PDF MS

    Thanks
    I think it's because in this instance it doesn't say that the radioactive fragments are taken from the total digest (so we assume it includes partial digests), so because three is the smallest radioactive fragment it is the first part of the sequence. The next radioactive fragment is 4kb, and since we've already established that the 3kb fragment is first, the only possible option is a partial digest of 3+1 = 4kb.
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    i have a feeling essay will be on Protein / Cell organelles / cell structures are related to their function. doubt variation will come up as it was in specimen paper nor disease causes as thats in june 2010....

    Any1 else agree?
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    Hello again guys!

    Just wondering the actual significance of souther blotting, cus I can't find anything in the NT book so I thought it's not gonna take up much in the exam. Can anyone outline the main parts for me, because I know the process, just not why it's so important.
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    Can anyone explain where in RNA H-bonds are?
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    (Original post by xelaman)
    Can anyone explain where in RNA H-bonds are?
    Only in tRNA, between bases to give that clover shape. And in double stranded RNA.
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    (Original post by appleschnapps)
    I think it's because in this instance it doesn't say that the radioactive fragments are taken from the total digest (so we assume it includes partial digests), so because three is the smallest radioactive fragment it is the first part of the sequence. The next radioactive fragment is 4kb, and since we've already established that the 3kb fragment is first, the only possible option is a partial digest of 3+1 = 4kb.
    Ok, but why isn't it a 3kb fragment, then a four one? I get the impression I'm missing the obvious here. There's four total digest, so three cut sites. One at 3, how do you know where the other two are?

    O------3------------4---------------


    Sorry for sounding really stupid...
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    In last years exam they ask and H-bonds are apparently found in all three (DNA, mRNA and tRNA) just wondering where they are in RNA
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    (Original post by xelaman)
    In last years exam they ask and H-bonds are apparently found in all three (DNA, mRNA and tRNA) just wondering where they are in RNA
    They definitely aren't in mRNA. It is a single polynucelotide strand.
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    (Original post by xelaman)
    In last years exam they ask and H-bonds are apparently found in all three (DNA, mRNA and tRNA) just wondering where they are in RNA
    There are no hydrogen bonds in mRNA. There are obviously in DNA, and also in tRNA between specific base pairs to hold the molecule in shape.
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    (Original post by xelaman)
    In last years exam they ask and H-bonds are apparently found in all three (DNA, mRNA and tRNA) just wondering where they are in RNA
    H-bonds are only in DNA and tRNA, not mRNA.
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    (Original post by Tericon)
    They definitely aren't in mRNA. It is a single polynucelotide strand.
    I suppose they form H bonds with the tRNA at translation??
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    A major resource for the essay. Hope they come in handy to you guys. Good luck! Also have a book (pdf) on writing the essay but it seems too big to attach
    Attached Images
  1. File Type: pdf biologysynopticstudentcreche.pdf (697.3 KB, 677 views)
 
 
 
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