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    (Original post by Satta101)
    Thanks dude!!
    Oh my god you have an offer from Bristol! I really really hope you get it. It's probably my first choice for when I apply this year
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    (Original post by nukethemaly)
    Oh my god you have an offer from Bristol! I really really hope you get it. It's probably my first choice for when I apply this year
    Hahaha! Yeah! I really hope so too if the biology exams go really well! Applying for medicine too? Good luck!
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    Hey guys,
    How about we do a group revision for unit 4 together ??
    You know, ask each other questions or something like that ...
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    (Original post by shumen9523)
    Hey guys,
    How about we do a group revision for unit 4 together ??
    You know, ask each other questions or something like that ...
    Yeah why not?! I need help with Unit 4 as well! Lets do it!
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    (Original post by Satta101)
    Yeah why not?! I need help with Unit 4 as well! Lets do it!
    I have a chemistry exam tomorrow, but I will partake in this after wednesday!
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    (Original post by nukethemaly)
    I have a chemistry exam tomorrow, but I will partake in this after wednesday!
    Same! Are you on OCR by any chance?
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    I'll join you guys too after Chemistry tomorrow :P, final week before Unit 4!:eek:
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    (Original post by Satta101)
    Same! Are you on OCR by any chance?
    Yep Salters OCR. How are you feeling about it?
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    (Original post by Satta101)
    Yeah why not?! I need help with Unit 4 as well! Lets do it!
    Great !!
    I'll start if nobody minds ....
    Q: Compare between the structural features of bacteria and viruses.
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    (Original post by shumen9523)
    Great !!
    I'll start if nobody minds ....
    Q: Compare between the structural features of bacteria and viruses.

    Urgh fml Why is bio so hard lmao
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    (Original post by yarshad)
    Urgh fml Why is bio so hard lmao
    I know what you mean ..
    The questions in the exam require thinking and analysis but there is so little time !!
    If you have any questions, post them here so that we can keep this thread alive.
    (hey that kinda rhymes :P )
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    (Original post by shumen9523)
    I know what you mean ..
    The questions in the exam require thinking and analysis but there is so little time !!
    If you have any questions don't hesitate to post them here so that we can keep this thread alive.
    After my two exams tomorrow I promise I'll ragg out this thread :P
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    (Original post by yarshad)
    After my two exams tomorrow I promise I'll ragg out this thread :P
    Good luck
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    (Original post by shumen9523)
    Great !!
    I'll start if nobody minds ....
    Q: Compare between the structural features of bacteria and viruses.
    BACTERIA:
    - cell surface membrane, cytoplasm, cell wall, ribosomes, plasmids and sometimes pilli, mesosomes and flagellum
    - circular strand of DNA
    - can live independently
    - average diameter 0.5 to 5 um
    - mucus based out capsule (slime capsule) protecting bacteria from attack (not all bacteria)

    VIRUSES:
    - no cell surface membrane, no cytoplasm, no cell wall and no organelles. Nucleic acid (DNA/RNA) enclosed in protein coat (capsid)
    - DNA/RNA = genetic material
    - must have living organism as host
    - variety of shapes and sizes
    - may have outer membrane (envelope) stolen from the hosts cell membrane. It contains glycoproteins from the virus

    Q: Why is only 2-10% of energy transferred from producers to primary consumers?
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    2 questions would really appreciate someones help:

    Can someone give me a CLEAR and CONSISE answers please

    (b) (i) Name two types of cell that HIV enters in the immune system.
    (ii) Explain how HIV is able to enter these cells.
    (iii) Describe the sequence of events following infection of these cells by HIV, that
    may lead to the death of the patient.
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    (Original post by itsjordan)
    BACTERIA:
    - cell surface membrane, cytoplasm, cell wall, ribosomes, plasmids and sometimes pilli, mesosomes and flagellum
    - circular strand of DNA
    - can live independently
    - average diameter 0.5 to 5 um
    - mucus based out capsule (slime capsule) protecting bacteria from attack (not all bacteria)

    VIRUSES:
    - no cell surface membrane, no cytoplasm, no cell wall and no organelles. Nucleic acid (DNA/RNA) enclosed in protein coat (capsid)
    - DNA/RNA = genetic material
    - must have living organism as host
    - variety of shapes and sizes
    - may have outer membrane (envelope) stolen from the hosts cell membrane. It contains glycoproteins from the virus

    Q: Why is only 2-10% of energy transferred from producers to primary consumers?
    Nice !!
    A/-Not all of the parts of the producers are eaten
    -Not all of the food that is eaten by the primary consumers is digested
    -Some energy is lost by respiration in the plants
    Q/ Suggest how the interspecific competition might affect the abundance and distribution of a certain population (give examples to clarify your answer if you wish)
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    (Original post by nukethemaly)
    Yep Salters OCR. How are you feeling about it?
    I do OCR Chemistry A, so I don't know if we sit the same paper? :confused:
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    (Original post by shumen9523)
    Good luck
    Fankzzz
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    (Original post by Taylor Swift)
    2 questions would really appreciate someones help:

    Can someone give me a CLEAR and CONSISE answers please

    (b) (i) Name two types of cell that HIV enters in the immune system.
    (ii) Explain how HIV is able to enter these cells.
    (iii) Describe the sequence of events following infection of these cells by HIV, that
    may lead to the death of the patient.
    b) i) Macrophages + T-helper cells
    ii) T-helper cells:
    - HIV binds to specific receptors on a T-helper cell
    - The lipid envelope around the HIV fuses with the cell membrane of the T-helper cell allowing the HIV to enter into it
    Macrophages:
    - They engulf the HIV
    - They take it in by endocytosis
    - The HIV would be incorporated into a vacuole
    iii) - The viral RNA would be converted into viral DNA by the enzyme reverse transcriptase
    - Viral DNA enters into the nucleus of the cell by the enzyme Integrase
    - It controls the cell's metabolism causing more viruses to be produced
    - These escape from the T helper cell causing the T helper cell to burst
    - The viruses infect other T helper cells
    - This causes the number of T helper cells to fall
    - which causes the immune system to weaken which exposes the body to opportunistic infections such as Tuberculosis

    -
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    (Original post by Satta101)
    I do OCR Chemistry A, so I don't know if we sit the same paper? :confused:
    We're both doing unit 2
 
 
 
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