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Official AQA Biology Unit 3 14th May 2013 NEW SPEC Watch

  • View Poll Results: VOTE HERE--> What do you think the 6 marker will be?
    Explaining features/functions of the lungs
    8.15%
    Ventilation
    11.11%
    Blood flow in heart
    16.30%
    Explain Transport in blood
    5.19%
    Explain Transport in plants
    5.19%
    Evaluate kidney transplants/dialysis
    28.89%
    Explain biogas generator
    31.11%
    Other (please comment with your suggestion)
    12.59%
    The effects of global warming
    8.15%
    Evaluate the use of Artificial blood
    13.33%
    Evaluate the effectiveness of sports drinks
    11.11%

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    (Original post by Hazwaz7)
    The surface is covered in microvilli, increasing its surface area to volume ratio and therefore increasing the amount of absorption that may occur as there are more surfaces that digested material may cross. The blood supply is good as capillaries run very close to the surface of the villi which helps to maintain a concentration gradient by moving absorbed material away. Also, the cells nearest to the surface are filled with mitochondria, used to supply lots of energy to the villi through respiration, needed for active transport.

    List 3 ways to reduce the risk of contamination in the production of mycoprotein? [3]
    Sterilise the fermenter before use, create an air-tight fermenter to reduce contamination and sterilise the air pumped into the fermenter.

    I can't think of any others. What would you have said?

    Why does a fermenter need to be surrounded by a jacket of cold water? [3]
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    does anyone know anything that i might have missed out? for unit 2, i didn't even realise that we needed to know about the plant tissues or anything and it ended up being the 6 marker!! it wasn't really emphasised in the revision guides, so is there anything that we need to know that i might have forgotten to learn or that should probably be learnt in a lot of depth? thanks
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    (Original post by Quantaˌ)
    Sterilise the fermenter before use, create an air-tight fermenter to reduce contamination and sterilise the air pumped into the fermenter.

    I can't think of any others. What would you have said?

    Why does a fermenter need to be surrounded by a jacket of cold water? [3]
    for your answer, you could say that the mycoprotein is heated after too in order to kill and bacteria?

    The cold water jacket keeps the system cool. If the system reaches above around 37 degrees, the mycoprotein production rate will be reduced. Due to the reaction being exothermic, it must be cooled using the water jacket to keep an optimum temperature.
    Positives and negatives of a Transplant rather than dialysis? [6]
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    (Original post by StudentWales)
    for your answer, you could say that the mycoprotein is heated after too in order to kill and bacteria?

    The cold water jacket keeps the system cool. If the system reaches above around 37 degrees, the mycoprotein production rate will be reduced. Due to the reaction being exothermic, it must be cooled using the water jacket to keep an optimum temperature.
    Positives and negatives of a Transplant rather than dialysis? [6]
    Hmmm I would put something about enzymes denaturing
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    I don't know about ventilators but for artificial blood: +don't have to be matched for blood group; can either increase blood volume (saline) or use oxygen carriers (haemoglobin capsules); good in countries where blood isn't screened (less chance of disease); has a shelf life of 3 years. - saline only useful if patient motionless (as doing less respiration), chemicals used to carry oxygen could be dangerous; encapsulated haemoglobin is undergoing trails on emergency patients so uncertain of safety.
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    (Original post by pinkgorilla)
    Somebody please answer this 6 marker. How would you answer this question to get the full 6 marks :

    Evaluate the use of artificial ventilators
    Evaluate the use of artificial blood and other heart products
    Evaluate the use of a biogas generator

    Sample answers would really be appreciated

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    sorry forgot to quote you^
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    (Original post by Fitzy07)
    I don't know about ventilators but for artificial blood: +don't have to be matched for blood group; can either increase blood volume (saline) or use oxygen carriers (haemoglobin capsules); good in countries where blood isn't screened (less chance of disease); has a shelf life of 3 years. - saline only useful if patient motionless (as doing less respiration), chemicals used to carry oxygen could be dangerous; encapsulated haemoglobin is undergoing trails on emergency patients so uncertain of safety.
    Heard of Perflurocarbons?
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    (Original post by StudentWales)
    for your answer, you could say that the mycoprotein is heated after too in order to kill and bacteria?

    The cold water jacket keeps the system cool. If the system reaches above around 37 degrees, the mycoprotein production rate will be reduced. Due to the reaction being exothermic, it must be cooled using the water jacket to keep an optimum temperature.
    Positives and negatives of a Transplant rather than dialysis? [6]
    Thanks. I forgot about heating. By the way, in your answer, I would have mentioned denaturing as well...

    The positives of a transplant include a free diet (no need to control your diet), no need to visit the hospital for dialysis and free from restrictions.

    Meanwhile, the disadvantages are the need for immosuppressant drugs, lack of donors, risk of inflection from surgery and risk of rejection.

    Explain the steps in ventilation. [4]
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    (Original post by Quantaˌ)
    Thanks. I forgot about heating. By the way, in your answer, I would have mentioned denaturing as well...

    The positives of a transplant include a free diet (no need to control your diet), no need to visit the hospital for dialysis and free from restrictions.

    Meanwhile, the disadvantages are the need for immosuppressant drugs, lack of donors, risk of inflection from surgery and risk of rejection.

    Explain the steps in ventilation. [4]
    inhalation - ribs up and out, intercostal muscles and diaphragm contract, volume increased inside and pressure decreased, so air is drawn in

    exhalation - muscles relax and diaphragm back to domed shape, ribs down and in, smaller volume and higher pressure forces air out

    How does the body react to an increase in body temperature? [4]
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    (Original post by MacDaddi)
    inhalation - ribs up and out, intercostal muscles and diaphragm contract, volume increased inside and pressure decreased, so air is drawn in

    exhalation - muscles relax and diaphragm back to domed shape, ribs down and in, smaller volume and higher pressure forces air out

    How does the body react to an increase in body temperature? [4]
    If there is a increase in body temperature, sweating and vasodilation (blood vessels dilate) occurs. If there is a decrease in body temperature, vasocontraction (blood vessels contract) and shivering (to produce energy from respiration) occurs.

    Explain how a kidney works [6]
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    (Original post by MacDaddi)
    How does the body react to an increase in body temperature? [4]
    • sweat glands secrete sweat and evaporates from the skin to remove heat
    • blood vessels dilate so heat can be transferred into the environment
    • hairs lie flat



    Suggest disadvantages and advantages of a patient being treated with an artificial heart [5]
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    (Original post by StudentWales)
    for your answer, you could say that the mycoprotein is heated after too in order to kill and bacteria?

    The cold water jacket keeps the system cool. If the system reaches above around 37 degrees, the mycoprotein production rate will be reduced. Due to the reaction being exothermic, it must be cooled using the water jacket to keep an optimum temperature.
    Positives and negatives of a Transplant rather than dialysis? [6]
    From past papers I have noticed they always want you to specifically say it's for temperature maintenence. 2nd mark is always stating that respiration releases energy to heat up fermenter. 3rd is always about enzymes not working at their optimal OR denaturing.
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    (Original post by Quantaˌ)
    If there is a increase in body temperature, sweating and vasodilation (blood vessels dilate) occurs. If there is a decrease in body temperature, vasocontraction (blood vessels contract) and shivering (to produce energy from respiration) occurs.

    Explain how a kidney works [6]
    1. Blood is taken into the Kidney by renal arteries
    2. Blood passes through porous filter
    3. excess water, urea, glucose and ions pass through a partially permeable membrane by diffusion
    4. Some ions, water and glucose are reabsorbed into the blood and pass out through the renal vein
    5. excess ions, water and the urea are passed to the bladder as urine

    How does a healthy person's body react to low levels of blood sugar [3]
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    (Original post by Quantaˌ)
    If there is a increase in body temperature, sweating and vasodilation (blood vessels dilate) occurs. If there is a decrease in body temperature, vasocontraction (blood vessels contract) and shivering (to produce energy from respiration) occurs.

    Explain how a kidney works [6]
    The blood is filtered into the kidney tubule so the protein stays in the blood as it is too large to fit through the filter. Selective re-absorption then occurs so that all the glucose is reabsorbed by active transport, the mineral ions and water needed are also reabsorbed. All the urea and the excess mineral ions and water are released into the bladder to be released as urine.

    Explain the process of producing biogas [6]
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    (Original post by MacDaddi)
    1. Blood is taken into the Kidney by renal arteries
    2. Blood passes through porous filter
    3. excess water, urea, glucose and ions pass through a partially permeable membrane by diffusion
    4. Some ions, water and glucose are reabsorbed into the blood and pass out through the renal vein
    5. excess ions, water and the urea are passed to the bladder as urine

    How does a healthy person's body react to low levels of blood sugar [3]
    It produces glucagon to convert glycogen into glycose which can be used for respiration.

    (Original post by jonathanparkes)
    The blood is filtered into the kidney tubule so the protein stays in the blood as it is too large to fit through the filter. Selective re-absorption then occurs so that all the glucose is reabsorbed by active transport, the mineral ions and water needed are also reabsorbed. All the urea and the excess mineral ions and water are released into the bladder to be released as urine.

    Explain the process of producing biogas [6]
    Slurry is added to a biogas generator. The generator works by anaerobic fermentation and, so, the bacteria produce methane. The generator is normally insulated, as the reaction is exothermic, to keep the bacteria at 30OC- the optimum temperature for enzyme action. Stirrers may be used to mixed the contents- bacteria and the slurry.

    Did I miss anything?


    Advantages and disadvantages of biofuels [6]
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    (Original post by Quantaˌ)
    It produces glucagon to convert glycogen into glycose which can be used for respiration.

    Advantages and disadvantages of biofuels [6]
    I would say that the pancreas produces the glucagon
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    (Original post by jonathanparkes)
    The blood is filtered into the kidney tubule so the protein stays in the blood as it is too large to fit through the filter. Selective re-absorption then occurs so that all the glucose is reabsorbed by active transport, the mineral ions and water needed are also reabsorbed. All the urea and the excess mineral ions and water are released into the bladder to be released as urine.

    Explain the process of producing biogas [6]
    biogas is produced in a generator. Waste is pumped in through an inlet in which the microorganisms in the generator undergo anaerobic respiration, also known as fermentation in order to ferment the waste and produce methane, which is the fuel gas in biogas. The digested material is removed through an outlet which can be used for fertilisers. There are two types of generators, batch and continuous.

    Idk what else to say tbh I don't see how this could be a 6 marker
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    (Original post by jonathanparkes)
    I would say that the pancreas produces the glucagon
    Remember the stored glycogen is in the liver
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    quick question: does the pulmonary artery transport DEoxygenated blood? or is that wrong...
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    Have you guys done all of the past papers?
 
 
 
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