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OCR F211/F212 AS Biology Retake 2016 Watch

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    (Original post by sabahk)
    I wrote they release cytokines
    That will probably be ok, because from what I understood interleukins are a type of cytokine? Or maybe I'm wrong

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    What was the answer to that animal kingdom taxonomic level question? And mechanism that stops fat breakdown ...last question?
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    can someone post all the questions that they remember please ?
    It would be really appreciated
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    Has anyone made an unofficial markscheme yettt?????
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    (Original post by shinycheetah)
    Has anyone made an unofficial markscheme yettt?????
    Don't think there will be as others have A2 exams soon

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    ive got the paper though i can scan it and post it here and then we can discuss answers but i think there's no time for that with F214 horror approaching in a few days time ))))))))
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    (Original post by milutin767)
    ive got the paper though i can scan it and post it here and then we can discuss answers but i think there's no time for that with F214 horror approaching in a few days time ))))))))
    Yes pls
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    Here it is. Couldn't bother to write out all the answers, just the first question lol. Hopefully this post won't be deleted
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    anyone know what the role of viral RNA was
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    (Original post by Em_vdw)
    anyone know what the role of viral RNA was
    Isn't it converted to DNA by reverse transcriptase and placed inside hosts genetic information?
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    (Original post by badhand45)
    Isn't it converted to DNA by reverse transcriptase and placed inside hosts genetic information?
    it asked how RNA was used in the production of viral proteins.

    i think you just had to talk about transcription
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    (Original post by CurleysWife)
    it asked how RNA was used in the production of viral proteins.

    i think you just had to talk about transcription
    Yeah but virus are not living organisms and have no DNA for transcription to occur. It cannot replicate without the host as it cannot mske its own proteins I think. Our teacher suggested it was overlapping A2 content because she was surprised to see that in?
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    What did you say about lily for 1 mark? The one about not being in its original habitat? I sad climate change in central africa, too hot so the mud is dry
    something like that
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    Can't be overlapping A2 content but I'm sure you'd get credit for mentioning reverse transcriptase but you don't need that
    just mentioning transcription and the host/virus from the question stem
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    [QUOTE=milutin767;65671499]Can't be overlapping A2 content but I'm sure you'd get credit for mentioning reverse transcriptase but you don't need that
    just mentioning transcription and the host/virus from the question

    But because virus dont have ribosomes they can't do protein synthesis. Ah well maybe because it was a suggest question you didn't need to know thst. But because most people doing it have done A2 and our teacher whos an examiner said she wouldn't be surprised if there was synoptic links. But you know what ocr are like hahq
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    (Original post by badhand45)
    Yeah but virus are not living organisms and have no DNA for transcription to occur. It cannot replicate without the host as it cannot mske its own proteins I think. Our teacher suggested it was overlapping A2 content because she was surprised to see that in?
    The virus uses the organelles and enzymes in the host's cells to produce new copies of itself. Suggest the role of the viral RNA in the production of viral proteins.

    That was the question.
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    (Original post by CurleysWife)
    The virus uses the organelles and enzymes in the host's cells to produce new copies of itself. Suggest the role of the viral RNA in the production of viral proteins.

    That was the question.
    I wrote "RNA converted to DNA by reverse transcriptase, this converted DNA is used in protein synthesis and therfore transcribes the viral proteins" something alomg those lines
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    (Original post by badhand45)
    I wrote "RNA converted to DNA by reverse transcriptase, this converted DNA is used in protein synthesis and therfore transcribes the viral proteins" something alomg those lines
    You'll probably get an alternative answer mark because that information is A2, which is not on the AS spec and technically we aren't meant to know that yet.
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    THIS IS JUST WHAT I THOUGHT THE ANSWERS WERE, FEEL FREE TO EDIT/ADD ANY WRONG OR ALTERNATIVE ANSWERS.

    1a)
    i) X = C, Y = O, Z = hydroxyl group
    ii) Draw beta glucose iii) Bond: 1,4-glycosidic bond ; disaccharide: maltose
    1b) Glycogen is an animal energy storage polysaccharide made up of alpha glucose joined together by 1,4-glycosidic bonds. It has branches due to 1,6-glycosidic bonds which allow hydrolysis at many branches for a faster rate of break down of glycogen into glucose for respiration. It is insoluble in water as it cannot form hydrogen bonds with water, and therefore does not affect the water potential of cells, can therefore be stored in cells easily.
    1c) beta pleated sheets, hydrogen, tertiary, chains, quaternary
    2a) active artificial
    2b)
    i) Viral mRNA uses host cells ribosomes to carry out transcription to produce viral proteins, process also uses tRNA.
    ii) Mutation in RNA causes a change to nucleotide base sequence, which causes different amino acids to be coded for, changing primary structure. Different primary structure causes coiling and folding at different parts of secondary structure as hydrogen bonds are formed differently. This therefore affects the tertiary structure of the protein, as bonds are formed differently (disulfide bonds, covalent bonds etc).
    iii) Less teachers taking sick leave and therefore won't be paid when not working.
    2c) lower, higher longer, shorter
    2d) T-killer cells: locate and destroy infected cells by releasing hydrogen peroxide into them. T-helper cells: release cytokines to attract B-lymphocytes T-memory cells: remain in the blood to provide immunological memory, and will divide into T-helper cells and T-killer cells upon repeat infection.
    3a)
    i) Add copper sulfate to solution, positive result will cause colour change from pale blue to lilac.
    ii) (NOT SURE ON THIS)
    3b) (NOT SURE ON ANY OF THIS)
    3c) These are examples of coenzymes and cofactors. They bind to the active site of the enzyme before the substrate binds. They link together series of enzyme-catalysed reactions. Examples include coenzyme A, NAD, FAD. (Not sure how to get 5 marks).
    4a) Organism survives on damp soil, however due to climate change the soil has dried out and therefore the organism cannot grow here.
    4b)
    i) 1: genetic diversity, 2: habitat diversity
    ii) allows us to develop medicines for human illnesses.
    iii) Plant diversity means that the crops will be more able to survive changes within the environment, whereas monocultures are unlikely to be able to survive these changes. Therefore, if there are any changes within the environment, then they will only lose some produce rather than all of their produce with a monoculture.
    4c) Use a stratified sample using a continuous belt transect. The environmental gradient would be from damp soil to dry soil (gradual change). Count all of the lilies in each quadrat and plot the number onto a graph which shows change in population against change in moisture. Repeat this experiment twice in order to increase reliability of findings.
    4d)
    i) CITES
    ii) Rio convention
    4e) Continuous variation describes the quantitative differences between organisms. There are very many intermediates between two extremes and there are no clearly distinguishable categories. Size of this organism is an example of this because it is a quantitative measurement with very many intermediates between two extremes.
    5)
    - Tar enters lines and settles on the walls of the airways and alveoli, increasing diffusion distance for oxygen to enter the blood and for carbon dioxide to leave. - Tar stimulates goblet cells to become enlarged and secrete excess mucus.
    - Tar paralyses and destroys cilia, meaning that mucus cannot be wafted away, causing a buildup of mucus in the airways and lungs.
    - Mucus containing trapped pathogens is not swept away, and pathogens divide within mucus. Presence of pathogens means lungs are more susceptible to infections.
    - Tar contains carcinogens such as benzopyrene which enters the nucleus of cells and causes a mutation in the DNA. This leads to uncontrollable mitosis and causes a mass of cells to be produced called a tumour. This is known as lung cancer.
    6a)
    i) Fungi
    ii) Does it have autotrophic nutrition?
    iii) Does it have fertilised eggs that develop into blastula?
    6b)
    i) Phylum, class, order, family
    ii) Slime moulds more closely related to plants and fungi. Evidence of classification may be that it has saprophytic nutrition, cell walls made of cellulose/chitin. Multinucleate cytoplasm.
    iii) (NOT SURE ON THIS).
    7a) Draw alanine.
    7b)
    i) Saturated fats are used in synthesis of LDLs (protein, cholesterol, saturated fats). LDLs decrease activity of receptors on liver, therefore less cholesterol taken up from blood into liver.
    ii) Increased blood cholesterol causes deposition on artery walls and damages the walls. Specialised phagocytes called monocytes repair damage, which causes growth of smooth muscle and deposition of fatty materials onto artery wall. This leads to formation of a plaque, which develops into an atheroma. This decreases width of artery lumen, increasing hydrostatic pressure of blood. This is atherosclerosis.
    7c) It is a competitive inhibitor for enzymes that break down fats in the small intestines.
    8a) Concentration.
    8b + c) Unsure on these... I thought the statements were correct lol.
    8d) Freezing retards bacterial enzymes and slows down reproduction rate of bacteria. This means that extracellular digestion cannot occur/occurs at a much slower rate and therefore food can be stored for a much longer period of time without becoming spoilt.
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    (Original post by sabahk)
    What was the answer to that animal kingdom taxonomic level question? And mechanism that stops fat breakdown ...last question?
    One of my teachers thinks you had to talk about competitive inhibitors, like oristol(spell?) acts as an inhibitor for lipase which breaks down fats, but I wrote some bs about removing water!

    And I have no clue about the one that was like why is the 3 domain classification favour above the 5 kingdoms method of classification!
 
 
 
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