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    A stimulus is detected by a receptor, which is a senseorgan. The electrical impulse travels down the sensory neurone to the centralnervous system, the spinal cord or the unconscious part of the brain. At asynapse between the sensory neurone and the relay neurone, the electricalimpulse diffuses across the gap in the form of a chemical substance. When thechemical substance reaches the relay neurone, it triggers another electricalimpulse to be sent. The same thing happens between the relay neurone and themotor neurone, and then an electrical impulse is sent along the motor neuroneto the effector. The effector is either a muscle (which contracts to bringabout movement) or a gland (which secretes hormones) which brings about a response.do you agree with this part in bold? sorry for so many questions, just want to make sure as it could be a 6 marker
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    (Original post by Nihaj)
    AQA B1!!!!! Hi guys, if you are stuck on any questions for B1 or don't understand something please feel free to ask me. It will help for your understanding and my revision.
    Basically anything to do with evolution, if you could help with the basics of it i'll know how to expand on that for an answer,
    Thanks.
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    (Original post by JSelby)
    Basically anything to do with evolution, if you could help with the basics of it i'll know how to expand on that for an answer,
    Thanks.
    Evolution refers to a change over time. It is believed that all living species evolved from simple life forms.

    Darwins theory:
    Darwin brought about the concept of natural selection
    Heres a typical answer:
    There is a variation in a species. Some variations are better suited to a habitat than others. The better suited animals are more likely to survive and reproduce. The next generation are likely to contain more individuals with the better suited genes.

    Lamarcks theory:
    Lamarck though that evolution occurred due to the inheritance of characteristics changed by the environment.
    (Lets take an example of a giraffe)
    The giraffe stretches to eat leaves. This means the giraffe's neck will stretch and become longer. The acquired characteristic is passed on to offspring
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    (Original post by jazz_xox_)
    thank you!! good luck , are you sitting your exam tomorrow?
    Yes im pretty confident :P Wish you luck
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    (Original post by jazz_xox_)
    A stimulus is detected by a receptor, which is a senseorgan. The electrical impulse travels down the sensory neurone to the centralnervous system, the spinal cord or the unconscious part of the brain. At asynapse between the sensory neurone and the relay neurone, the electricalimpulse diffuses across the gap in the form of a chemical substance. When thechemical substance reaches the relay neurone, it triggers another electricalimpulse to be sent. The same thing happens between the relay neurone and themotor neurone, and then an electrical impulse is sent along the motor neuroneto the effector. The effector is either a muscle (which contracts to bringabout movement) or a gland (which secretes hormones) which brings about a response.do you agree with this part in bold? sorry for so many questions, just want to make sure as it could be a 6 marker
    Lol this could answer a 8 mark question. Great job this will defo get you the 6 marks
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    Can someone explain the nitrogen cycle to me which is simplified but would still get 6/6
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    (Original post by Zellaforever)
    Can someone explain the nitrogen cycle to me which is simplified but would still get 6/6
    I dont believe that the nitrogen cycle is in the aqa spec but i could explain the carbon cycle to you

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    (Original post by hafsa23)
    Adult cell cloning please
    Hey.
    Adult cell cloning is pretty easy once you get the hang of it. Adult cell cloning is when an egg cell is taken from an animal, say a prize cow. Then a regular, unspecialised cell is taken from the prize cow too. The nucleus is removed from the egg cell and disposed of. The nucleus from the adult cell, is taken and fused with the egg cell membrane (using an electric shock). This cell is then left to grow until a few clones of the cells has been made, where the cloned cells can be implanted into the uterus of a surrogate mother (a random cow). These cell clusters will develop into baby clones of the prize cow.
    Sorry if it's a bit confusing, hope this helps
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    (Original post by georgiaesmehare)
    Hey.
    Adult cell cloning is pretty easy once you get the hang of it. Adult cell cloning is when an egg cell is taken from an animal, say a prize cow. Then a regular, unspecialised cell is taken from the prize cow too. The nucleus is removed from the egg cell and disposed of. The nucleus from the adult cell, is taken and fused with the egg cell membrane (using an electric shock). This cell is then left to grow until a few clones of the cells has been made, where the cloned cells can be implanted into the uterus of a surrogate mother (a random cow). These cell clusters will develop into baby clones of the prize cow.
    Sorry if it's a bit confusing, hope this helps
    i Thought the prize cow and bull were an example for cloning using embryo transplants, sorry im confuzzled
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    Auxin's please
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    (Original post by jaebum)
    Auxin's please
    When plants grow in response to light it is known as phototropism

    When plants grow in response to gravity it is known as geotropism

    Phototropism:
    When light shines at a plant auxin is produced in the shaded side of the shoot (the side opposite the light/sun) Auxin causes cells in the shoot of the plant to elongate as auxin promotes cell growth. Therefore the plant bends and grows towards the light.

    Geotropism:
    Auxin is produced in the root tip. Auxin will accumulate on the lower side of the root due to gravity. The auxin inhibits elongation in these cells so the root will eventually bend and grow in the direction of gravity
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    I need help with GM
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    (Original post by hafsa23)
    i Thought the prize cow and bull were an example for cloning using embryo transplants, sorry im confuzzled
    Yeh it is an example. Prize cow isn't the only thing that can be cloned. Any animal can be cloned but cows and bulls usually come up in these questions. Just get the general knowledge of adult cell cloning and you will be able to implement it in any answer.
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    (Original post by u_mahmood101)
    I need help with GM
    Remember that GM stands for genetically modified

    Okay so lets say a bacteria has a gene that produces poison that kills insects. And we want this gene in plants so that the plants can have poison that kills insects. This would be a 4 mark question:

    The gene from the bacteria that produces the poison is cut using enzymes. This gene is then transferred to the DNA of the plant cell at early stage of development. The plant now has the poison producing gene and can now kill insects which means the plant can live for longer.
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    I understand that genetic engineering can be used to produce human insulin in a bacterium, but how does this help with diabetes? Are the bacteria inserted into the pancreas?
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    (Original post by Ishan_2000)
    Good detail....but you missed out CNS, or spinal cord/brain! Which is a crucial part of the reflex arc.
    Also, (being picky, I know) you could add that the response is the muscle contraction.
    Reflex arcs don't require CNS as it save time. Think about it. If you are touching a hot pan you would want yor hand to move away as quickly as possible. Using your brain takes time
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    What is genetic engineering
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    (Original post by bigboxman8)
    Reflex arcs don't require CNS as it save time. Think about it. If you are touching a hot pan you would want yor hand to move away as quickly as possible. Using your brain takes time
    CNS is your spinal cord or brain. I'm pretty sure the reflex arc needs one of these to function. The CNS actually decides what to do with the receptor, and what response should happen.

    http://www.bbc.co.uk/schools/gcsebit...stemrev2.shtml
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    (Original post by jazz_xox_)
    I understand that genetic engineering can be used to produce human insulin in a bacterium, but how does this help with diabetes? Are the bacteria inserted into the pancreas?
    Bacteria reproduce rapidly, and perform asexual reproduction, so produce exact clones of themselves. So, every single bacteria offspring will have the human insulin gene in them, so can make human insulin.

    I think that scientists can easily take this insulin out of bacteria, and collect it in a jar or something, so the insulin can then be given to diabetes patients, who don't have enough insulin. Since there's lots of bacteria, there's a lot of insulin collected quickly.
 
 
 
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