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    (Original post by terminatorsb)
    EXAM DAY!!!!!You are a Genius but we arent Pedus
    i aint a genious. im just relaxed about it. because i kno ive revised my arse off last few days.

    you'll be fine anyways mate.. is that chat thing still going from yesterday?
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    Scary times.

    Pedus how confident you feeling with the article?
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    (Original post by dynamikal)
    Scary times.

    Pedus how confident you feeling with the article?
    Not that confident. About to go through it in a bit... you?
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    Good luck you guys who have biology today im sure you will be fine. I dropped it last year, but maybe i can give you guys a testing revision question (or not) :


    How can a rat gene be inserted into a fruit fly ?
    i just know this question, because i know someone doing biology, and they were revising this
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    (Original post by Da_hopeful_1)
    Good luck you guys who have biology today im sure you will be fine. I dropped it last year, but maybe i can give you guys a testing revision question (or not) :


    How can a rat gene be inserted into a fruit fly ?
    i just know this question, because i know someone doing biology, and they were revising this
    ha thats deciation :cool:

    umm I would say get mRNA of gene use reverse transcriptase to make SS DNA. Add nucleotides + DNA polymerase to make DS DNA.

    Cut DNA of plasmid w/ restriction enzyme, ensure "sticky ends" match. Use DNA ligase to join sticky ends and then insert the gene
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    hey guys

    just want to say thanks for all your help on this thread and good luck with the exam today although i'm sure you won't need it
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    (Original post by 03eleitch)
    hey guys

    just want to say thanks for all your help on this thread and good luck with the exam today although i'm sure you won't need it

    will the paper be the hardest so far ?
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    Hey, are you guys being prepared for the pre-released paper?
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    absolutely ******** it!!! Mind blank times lol
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    C'mon guys! This is IT! We can do this! :dumbells:
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    Where does it say that we will be provided with the article in the examination? it is not mentioned in the spec :s
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    http://www.biologymad.com/resources/...omeostasis.pdf
    http://www.biologymad.com/resources/....pps#256,1,The Nervous System
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    (Original post by DTCM)
    Where does it say that we will be provided with the article in the examination? it is not mentioned in the spec :s
    Ha! I'd have hoped that the "Do not return this insert with the question paper" on the front of it kind of implies that but, if it doesn't...! Actually the specimen didn't really have any quoting / data from the article - it was more just a 'context' for the synoptic issues - even more annoying!
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    (Original post by fizzybubble)
    There haven't been any papers before. This is the first sitting.

    i mean compared to the other units
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    DO READ THIS

    pinnipedlab.ucsc.edu/media/lindemann/Ch.4_The%20brain.pdf
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    Could someone plz go over the methods for gene therapy as there is not much on it in the AS CGP book

    Thank you
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    I'm going school now for revision! Good luck everybody..& thanks for all the resources you been posting
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    yeah my snab hasn't worked for a while now
    it doesn't let me log in
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    All you need to know about Human Genome Project and GM rops!

    Spoiler:
    Show
    Discuss whether or not you think it is right to use animals such as rats and monkeys to research the
    possible effects of drugs like ecstasy on humans.?

    Students may comment that animals with advanced nervous systems are more likely to suffer than more
    primitive animals. Ability to experience pain, and self-awareness may be discussed.
    Some people consider that animals have rights so we have a duty to protect these rights. The species of
    animal may or may not affect people’s perception of an animal’s rights.
    The more closely related animals are to humans, the more useful the research. By and large, the more
    DNA animals have in common with humans, the more similar their physiology is to human physiology.
    Responses to the first two questions may lead to a discussion of the costs and benefits of animal
    research. It is more useful to use mammals than, for example, invertebrates in research on human
    physiology. As mammals have a more developed nervous system, it could be argued that it is more
    wrong to exploit them in research. People’s response to this question depends on how they value human
    life and removal of human suffering compared with animal life and suffering


    Spoiler:
    Show
    Describe the process of genetic modification.
    Genetic modification of animals should include the following steps:
    • inserting DNA into the nucleus of a fertilised egg, either by injecting, using a retrovirus or liposomes
    • implanting the egg into a surrogate female.


    Spoiler:
    Show
    Write a short paragraph to justify one of the potential risks and one of the potential benefits of GM crops.
    Could help to feed the developing world – Approximately one third of crops worldwide are lost to disease
    and pests, and so GM crops resistant to disease and pests would increase yield. GM crops could increase
    yield in hostile conditions such as drought, and extend the amount of land available for agriculture.
    GM crops are more cost-effective – GM crops that produce chemicals with altered composition (e.g. starch
    and oils) could reduce costs in manufacturing certain products.
    Could benefit human health – GM crops could be modified to contain modified nutritional contents that
    would have health benefits. The activity sheet mentions Golden Rice – this has a high vitamin A content, and
    reduces the number of people suffering the consequences of vitamin A deficiency. Farmers producing food
    in developing countries sometimes use pesticides that are banned in developed countries. This can damage
    their health. If GM crops didn’t need pesticides, this damage to health would not happen. GM crops (pharma
    crops) could allow cheap production of drugs, including ones which are currently very expensive, and so
    unlikely to be widely available particularly in developing countries. There’s the potential to produce GM
    crops containing vaccines for certain conditions. This may allow people access to vaccines without
    specialised storage (such as refrigeration).
    Could reduce pesticide and herbicide use – Reduced chemical use would be beneficial to health and reduce
    the cost of crop production. Herbicide-tolerant crops would allow one type of herbicide to be used all year
    round, reducing the need for a complex mixture of herbicides to be applied at different times of year. Also,
    crops able to produce their own insecticides (e.g. Bt toxin) reduce the need for pesticides.
    Could preserve natural habitats – Reduced use of pesticides and herbicides could mean that there’s less
    impact on surrounding habitats. Currently, natural habitats are being cleared to allow more space for crops
    with a low yield. If higher yield crops were introduced, there would be no need to clear more habitats for
    crops.
    Will not be able to feed the world – Many people argue that worldwide hunger issues are not based on an
    inability to produce enough food. There is enough food to go around if it was distributed equally. It’s more a
    problem of politics, poverty and trading, which will not be solved using GM crops.
    Could damage organic farmers – If GM crops are able to crossbreed with organic crops, then the organic
    crops are no longer considered to be organic. This would damage the livelihood of organic farmers.
    May have unpredictable health risks – We cannot know the consequences of transferring genes across the
    species barrier. Proteins produced may be dangerous (toxic or initiate allergic responses), either directly, or
    indirectly through metabolic processes. Pharma crops may breed with conventional crops, meaning that there
    are potentially harmful chemicals entering the food chain.
    Could increase herbicide and pesticide use – The genes used for increased herbicide resistance in GM crops
    may spread to other plants, including weeds. This may allow for the development of resistant ‘superweeds’.
    Therefore, there would be increased herbicide use to kill the ‘superweeds’. GM crops able to produce
    insecticides could allow insects to develop resistance. If the insects are exposed to a constant high dose of an
    insecticide (a selection pressure), mutants resistant to the insecticide would be selected for. This would allow
    ‘superbugs’ to develop, requiring an increasing use of chemicals on crops.
    Could reduce biodiversity – It has been argued that the use of GM crops reduces the chance of other plants or
    insects existing within the crop, and hence reduces biodiversity. However, it is argued that this is essentially
    the same as farming a specific crop. Superweeds resulting from transfer of genes from GM crops to weed
    species could result in weeds outcompeting native wild species.
    Mainly benefits big biotech companies – Biotech companies have the opportunity to patent genes, techniques
    and crops they develop. This means that any profit generated by this technology is owned solely by one
    company. These companies are private companies, who are interested in the technology to make profit, not
    necessarily for the greater good of humanity.
    Raises ethical conflicts over the control of food production – As big biotech companies hold patents for these
    technologies, they have sole control. This may mean that they have too much influence over food production
    in developing countries. Many crops generated are infertile, and so farmers are unable to keep seeds from a
    crop in order to plant the following year. Therefore, if they want to grow the same GM crop the following
    year they need to buy seeds again, which many farmers in developing countries cannot afford.


    Spoiler:
    Show
    All ethical issues related to HGP and Genetic engineering
    Attached.


    To review the structure and function of synapses.
    • To look at the effect of ecstasy on serotonin synapses.


    Spoiler:
    Show
    The recreational drug ecstasy (MDMA) produces pleasurable feelings of well-being and empathy. The
    drug’s effects are due to the altered levels of serotonin in the user.
    Serotonin is a neurotransmitter found in the brain. It is involved in pathways that control mood, emotions,
    sleeping and waking, feeding and temperature regulation. Low levels of serotonin are associated with
    feelings of anxiety, depression and drowsiness. Serotonin networks stimulate part of the base of the brain,
    called the limbic system. The limbic system is responsible for ‘pleasure pathways’ that produce rewarding
    feelings in response to activities that are essential to life such as drinking, eating and sex. This reward system
    increases the probability that someone will engage in a given behaviour and continue that behaviour.

    Q3 Suggest how the molecular structure of ecstasy might relate to its action at serotonin synapses.
    Q4 Explain why taking ecstasy produces a ‘high’, i.e. feelings of well-being.
    Q5 How might the action of ecstasy increase the probability that someone will take it again?
    How do we know about the effects of ecstasy?
    Research using animal models such as rats and monkeys has provided us with detailed understanding about
    the action and toxicity of ecstasy.
    Ecstasy is a toxin which acts on the brain. Animals have an important role in toxicity studies, as society
    holds that it is not acceptable to study toxicity in living humans. In one study of the effects of ecstasy,
    monkeys were given ecstasy twice a day for four days. Control monkeys were given saline. Two weeks later,
    sections taken from the brain of a control monkey showed the presence of a lot of serotonin whereas in
    monkeys receiving ecstasy most of the serotonin had gone. It appears the serotonin that is not reabsorbed by
    the neurones is lost and the neurones can’t make serotonin fast enough to replace the serotonin that is lost.
    Brain sections showed that even seven years after taking ecstasy, the levels of serotonin in the brain had not
    returned to normal. Synapses in the serotonin pathway, destroyed during use of ecstasy, are not completely
    replaced.
    Q6 Research on monkeys suggests that serotonin production in ecstasy users is reduced, even after the
    drug has gone from the body. What effect will this have on the user?
    Attached Images
  1. File Type: pdf Ethics in bio.pdf (384.4 KB, 253 views)
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    Pedus u gonna go online on the chat room at 6BIO5??
    tell me soon
 
 
 
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