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    (Original post by terminatorsb)
    wat do u mean unreliable
    wats the point
    u cud just join in with the other people in 6BIO5
    Kept crashing.
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    From reading the "stressed out" part of the article I seem to be gathering that stress causes the release of noradrenaline; this then binds to b-adrenoreceptors stimulating production of cyclic AMP, which is important in the release of neurotransmitters, including noradrenaline. Repeated stimulation causes both the number of b-adrenoreceptors to fall and makes noradrenaline less able to stimulate the production of cyclic AMP, so less neurotransmitter is produced. This is a coping mechanism for stress, but noradrenaline is still needed as a coping mechanism.

    Yeah, that seems a bit convoluted. I can kinda make links between bits; anyone care to clean up any of that slightly, if it seems vastly incorrect?
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    Hi

    I am abit worried about the exam tommorow as I went to my teacher earlier to get some revision notes and he reminded me that there could be questions on the core practicals!

    I think he said they were for the spirometer and habituation of snails. I was absent for both of these and the SNAB website is down and has been down for a few hours. :eek3:

    Does anyone have these core practicals or any notes that I need to know?

    Would be greatly appreciated if anyone can help! x
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    where is everyone getting their past papers from?
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    What are people doing about the pre-released material? don't really know what to do to prepare.
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    (Original post by Simone_)
    Hi

    I am abit worried about the exam tommorow as I went to my teacher earlier to get some revision notes and he reminded me that there could be questions on the core practicals!

    I think he said they were for the spirometer and habituation of snails. I was absent for both of these and the SNAB website is down and has been down for a few hours. :eek3:

    Does anyone have these core practicals or any notes that I need to know?

    Would be greatly appreciated if anyone can help! x
    I wasn't there either, but I've got notes

    Habituation:
    Get an African land snail, leave it on a clean surface and wait for it to come out of it's shell. Dampen a cotton wool buf and firmly touch it between the eyes. Time how long it takes to come out again. Repeat.

    Breathing:
    Basically just using a spirometer to show tidal volume and vital capacity. Soda lime is used to remove CO2 to prevent the person dying :/

    Oxygen Uptake:
    Using maggots and soda lime, measure the decrease in the volume of air in the boiling tube every minute, using a capillary tube. Again soda lime absobs Co2 so the volume decrese = O2 used in respiration.

    Hope that's usefull, feel free to add to it
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    :confused:
    (Original post by MTGjumper)
    From reading the "stressed out" part of the article I seem to be gathering that stress causes the release of noradrenaline; this then binds to b-adrenoreceptors stimulating production of cyclic AMP, which is important in the release of neurotransmitters, including noradrenaline. Repeated stimulation causes both the number of b-adrenoreceptors to fall and makes noradrenaline less able to stimulate the production of cyclic AMP, so less neurotransmitter is produced. This is a coping mechanism for stress, but noradrenaline is still needed as a coping mechanism.

    Yeah, that seems a bit convoluted. I can kinda make links between bits; anyone care to clean up any of that slightly, if it seems vastly incorrect?
    I got a bit confused with this, if noradrenaline means less cAMP is made, then surely less noradrenaline can be made as cAMP helps relase neurotransmitters. But the next line says 'so stress increases the amount of noradrenaline'. Help :confused:
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    hey guys, in terms of flies, why would 'off the shelf' strains be better?
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    is anyone comfortable enough to do this exam?
    • Thread Starter
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    I'm going to post summaries for STRESS and Pain+Gender later on.
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    our bio profess just sent us the pre released material... awesome
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    (Original post by skotch)
    May as well type up the 2nd set of questions seeing as I'm bored...

    ...and before I get a million PMs about it, no, I don't have answers or a mark scheme, these are made up by my teachers and I haven't even done them yet so I don't have any answers.

    Here we go:

    Dancing Worms and Deep Depression
    Spoiler:
    Show
    1. Describe the sequence in the neuronal pathway to make the worm clench its muscles.

    2. What is taking place at the neuromuscular junction of the worm to elicit a 'jump'?

    3. Suggest how the 'forward' and 'backward' jump might work in terms of excitatory and inhibitory synapses.

    4. Normal cells don't respond to a light stimulus except the rhodopsin and iodopsin containing rods and cone cells. How could the scientists engineer neuronal cells that are sensitive to light?

    5. Explain the sequence of events starting from zapping a neuron with a wire electrode to seeing an electrical spike.

    6. Explain how deep brain stimulation (DBS) as a therapy is able to target only a small area of the brain as opposed to standard drug therapy which acts throughout the brain.

    7. what is the vagal nerve? Where does it start and where does it end?

    8. How does the vagal nerve affect breathing rate? Is this the parasympathetic or sympathetic arm of the CNS?

    9. What goes wrong in Parkinson's Disease?

    10. What is the subthalamic nucleus (STN) and what does it normally do? What is it's role in Parkinson's Disease?

    11. What kind of brain imaging technology can make the active or depressed parts of the brain light up?

    12. How can electrical stimulation of the STN accidentally turn on nearby nerve fibres?

    13. What is the limbic system?

    14. Miesenbock's approach of injecting light sensitive ATP in animal brains was a killer limitation for future applications, why?

    15. What cellular processes did expressing the ChR2 gene in nerve cells in a Petri dish involve? N.B. ChR2, like NpHR, is a membrane protein.

    16. How can you genetically engineer an animal to manufacture light-sensitive proteins?

    17. How is the experiment with the rat's barral cortex an example of a conditioned reflex?

    18. Why is the use of 'off-the-shelf' strains of flies better than using ordinary flies?

    19. Behaviours such as grooming, mating and fighting are likely to be controlled by polygenes. How is this likely to complicate assigning specific responses to specific neurones?

    20. What is retinitis pigmentosa and which cells - rods or cones - does it destroy?

    21. Pan's experiment with mice appeared to work. What does this tell us about the visual cortex of the mice?


    Stressed Out
    Spoiler:
    Show
    22. How does adrenaline/noradrenaline mediate the fight or flight response?

    23. Compare and contrast the effect of adrenaline as a hormone with its action as a neurotransmitter.

    24. Stress, an environmental stimulus, induces the increased expression of enzymes needed to synthesise noradrenaline in neurones. How does this help people cope with everyday stress?

    25. Harmless repeated handling of untamed rats reduces the number of receptors for noradrenaline. This is learning through habituation. How does this match with the theory you have learned in your textbook?

    26. How does cAMP act on DNA to modulate the synthesis of neurotransmitters?

    27. How can hydroxyl-dopamine selectively destroy the neurones that use noradrenaline as a neurotransmitter?

    28. What is the evidence that it is an imbalance of many different neurotransmitters and not just one neurotransmitter in particular that can cause stress-related disorders?


    Pain and Gender
    Spoiler:
    Show
    29. How do painkillers like morphine work to reduce the feeling of pain?

    30. Why can we describe pain as a polygenic inherited trait?

    31. Suggest how oestrogen and progesterone might cause their antagonistic effects on the neurones.

    32. Why did male rats have to be castrated and female rats to be sterilised for Levine's experiments?

    33. Suggest how a chemical could block pain and counteract the effect of analgesics.

    34. Which brain scanning technology would have been used by Anthony Jones to visualise the parts of the brain engaged in pain experience?


    If you have any questions about how to answer the questions, feel free to ask me as we've gone over some of the questions in class.
    do u have the ans for these Q's now?
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    (Original post by Soda__Dreamer)
    is anyone comfortable enough to do this exam?
    it'd be easier if we knew what to expect :yep:
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    Hi guys, does anyone have the salters nuffield mark scheme for june 2009?
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    does anyone know where i can get the mark scheme for the unit 5 Sample Assessment Material 6BI05/1 paper.
    Doing the paper now as practice but don't have the mark scheme to check my answers
    If anyone knows where or even if i can get it that would be GREAAATT. Ta
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    (Original post by _joshb_)
    Is this detected via pH by chemoreceptors?


    Are there any receptors in the neck? Or are they all in the carotid artery?

    Also do you know what a 'stretch receptor' is?
    Yeah all rises/falls in carbon dioxide are detected by chemoreceptors;
    I thought the carotid artery was in the neck

    A stretch receptor is stimulated upon an increase in volume of air in the thorax; this sends impulses that inhibit the inspiratory centre in the medulla; then elastic recoil of the aveloi pushes the air out of the lungs
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    (Original post by Soda__Dreamer)
    is anyone comfortable enough to do this exam?
    Yeah I just want to get it over and done with now; topic 7 and 8 I am fine with its just the article I am slightly worried about in terms of what kinds of questions they are going to ask.
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    32. Why did male rats have to be castrated and female rats to be sterilised for Levine's experiments?
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    (Original post by H.Anne)
    does anyone know where i can get the mark scheme for the unit 5 Sample Assessment Material 6BI05/1 paper.
    Doing the paper now as practice but don't have the mark scheme to check my answers
    If anyone knows where or even if i can get it that would be GREAAATT. Ta
    http://www.edexcel.com/migrationdocu...ce-biology.pdf
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    (Original post by poojatanwani7)
    I'm stuck on the article! I get everything except for the noradrenaline bit in the 'Stressed out' section, it says more noradrenaline is synthesized with repeated stress as a coping mechanism but shouldn't it be the other way around because the neurons are getting habituated? Also what exactly does noradrenaline do in the coping of stress? Thanks in advance for any help!
    So when stress is repeated, noradrenaline levels increase. BUT the number of b-adrenoreceptors decrease I think this is the adaptation. Also noradrenaline is less able to synthesise cyclic AMP as the b-adrenorecptors have decreased sensitivity.

    Its not known for sure exactly how noradrenaline works, just that its increase its likely to be an effect of stress and not a cause.

    Well thats my interpretation, hope it helps! its really confusing :woo:
 
 
 
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